From a30d2030fc45da5e146ae7bd710e31649a257842 Mon Sep 17 00:00:00 2001
From: ellebi2000 <lorenzobattistelli.2000@gmail.com>
Date: Sat, 25 May 2024 12:57:03 +0200
Subject: [PATCH 01/11] added mqtt pub/sub example

---
 pico_w/mqtt/CMakeLists.txt             |   0
 pico_w/mqtt/mqtt_client/CMakeLists.txt |   0
 pico_w/mqtt/mqtt_client/lwipopts.h     |  90 ++++++++++++++
 pico_w/mqtt/mqtt_client/mqtt_client.c  | 158 +++++++++++++++++++++++++
 4 files changed, 248 insertions(+)
 create mode 100644 pico_w/mqtt/CMakeLists.txt
 create mode 100644 pico_w/mqtt/mqtt_client/CMakeLists.txt
 create mode 100644 pico_w/mqtt/mqtt_client/lwipopts.h
 create mode 100644 pico_w/mqtt/mqtt_client/mqtt_client.c

diff --git a/pico_w/mqtt/CMakeLists.txt b/pico_w/mqtt/CMakeLists.txt
new file mode 100644
index 000000000..e69de29bb
diff --git a/pico_w/mqtt/mqtt_client/CMakeLists.txt b/pico_w/mqtt/mqtt_client/CMakeLists.txt
new file mode 100644
index 000000000..e69de29bb
diff --git a/pico_w/mqtt/mqtt_client/lwipopts.h b/pico_w/mqtt/mqtt_client/lwipopts.h
new file mode 100644
index 000000000..9e71835b9
--- /dev/null
+++ b/pico_w/mqtt/mqtt_client/lwipopts.h
@@ -0,0 +1,90 @@
+#ifndef _LWIPOPTS_EXAMPLE_COMMONH_H
+#define _LWIPOPTS_EXAMPLE_COMMONH_H
+
+
+// Common settings used in most of the pico_w examples
+// (see https://www.nongnu.org/lwip/2_1_x/group__lwip__opts.html for details)
+
+// allow override in some examples
+#ifndef NO_SYS
+#define NO_SYS                      1
+#endif
+// allow override in some examples
+#ifndef LWIP_SOCKET
+#define LWIP_SOCKET                 0
+#endif
+#if PICO_CYW43_ARCH_POLL
+#define MEM_LIBC_MALLOC             1
+#else
+// MEM_LIBC_MALLOC is incompatible with non polling versions
+#define MEM_LIBC_MALLOC             0
+#endif
+#define MEM_ALIGNMENT               4
+#define MEM_SIZE                    4000
+#define MEMP_NUM_SYS_TIMEOUT        (LWIP_NUM_SYS_TIMEOUT_INTERNAL+1)
+#define MEMP_NUM_TCP_SEG            32
+#define MEMP_NUM_ARP_QUEUE          10
+#define PBUF_POOL_SIZE              24
+#define LWIP_ARP                    1
+#define LWIP_ETHERNET               1
+#define LWIP_ICMP                   1
+#define LWIP_RAW                    1
+#define TCP_WND                     (8 * TCP_MSS)
+#define TCP_MSS                     1460
+#define TCP_SND_BUF                 (8 * TCP_MSS)
+#define TCP_SND_QUEUELEN            ((4 * (TCP_SND_BUF) + (TCP_MSS - 1)) / (TCP_MSS))
+#define LWIP_NETIF_STATUS_CALLBACK  1
+#define LWIP_NETIF_LINK_CALLBACK    1
+#define LWIP_NETIF_HOSTNAME         1
+#define LWIP_NETCONN                0
+#define MEM_STATS                   0
+#define SYS_STATS                   0
+#define MEMP_STATS                  0
+#define LINK_STATS                  0
+// #define ETH_PAD_SIZE                2
+#define LWIP_CHKSUM_ALGORITHM       3
+#define LWIP_DHCP                   1
+#define LWIP_IPV4                   1
+#define LWIP_TCP                    1
+#define LWIP_UDP                    1
+#define LWIP_DNS                    1
+#define LWIP_TCP_KEEPALIVE          1
+#define LWIP_NETIF_TX_SINGLE_PBUF   1
+#define DHCP_DOES_ARP_CHECK         0
+#define LWIP_DHCP_DOES_ACD_CHECK    0
+
+#ifndef NDEBUG
+#define LWIP_DEBUG                  1
+#define LWIP_STATS                  1
+#define LWIP_STATS_DISPLAY          1
+#endif
+
+#define ETHARP_DEBUG                LWIP_DBG_OFF
+#define NETIF_DEBUG                 LWIP_DBG_OFF
+#define PBUF_DEBUG                  LWIP_DBG_OFF
+#define API_LIB_DEBUG               LWIP_DBG_OFF
+#define API_MSG_DEBUG               LWIP_DBG_OFF
+#define SOCKETS_DEBUG               LWIP_DBG_OFF
+#define ICMP_DEBUG                  LWIP_DBG_OFF
+#define INET_DEBUG                  LWIP_DBG_OFF
+#define IP_DEBUG                    LWIP_DBG_OFF
+#define IP_REASS_DEBUG              LWIP_DBG_OFF
+#define RAW_DEBUG                   LWIP_DBG_OFF
+#define MEM_DEBUG                   LWIP_DBG_OFF
+#define MEMP_DEBUG                  LWIP_DBG_OFF
+#define SYS_DEBUG                   LWIP_DBG_OFF
+#define TCP_DEBUG                   LWIP_DBG_OFF
+#define TCP_INPUT_DEBUG             LWIP_DBG_OFF
+#define TCP_OUTPUT_DEBUG            LWIP_DBG_OFF
+#define TCP_RTO_DEBUG               LWIP_DBG_OFF
+#define TCP_CWND_DEBUG              LWIP_DBG_OFF
+#define TCP_WND_DEBUG               LWIP_DBG_OFF
+#define TCP_FR_DEBUG                LWIP_DBG_OFF
+#define TCP_QLEN_DEBUG              LWIP_DBG_OFF
+#define TCP_RST_DEBUG               LWIP_DBG_OFF
+#define UDP_DEBUG                   LWIP_DBG_OFF
+#define TCPIP_DEBUG                 LWIP_DBG_OFF
+#define PPP_DEBUG                   LWIP_DBG_OFF
+#define SLIP_DEBUG                  LWIP_DBG_OFF
+#define DHCP_DEBUG                  LWIP_DBG_OFF
+#endif /* __LWIPOPTS_H__ */
\ No newline at end of file
diff --git a/pico_w/mqtt/mqtt_client/mqtt_client.c b/pico_w/mqtt/mqtt_client/mqtt_client.c
new file mode 100644
index 000000000..ed94104a9
--- /dev/null
+++ b/pico_w/mqtt/mqtt_client/mqtt_client.c
@@ -0,0 +1,158 @@
+//
+// Created by elliot on 25/05/24.
+//
+#include "pico/stdlib.h"
+#include "hardware/gpio.h"
+#include "hardware/irq.h"
+#include "hardware/adc.h"
+#include "pico/cyw43_arch.h"
+#include "lwip/apps/mqtt.h"
+
+
+// Temperature
+#define TEMPERATURE_UNITS 'C'
+
+// WiFi
+#define WIFI_SSID "Elliot"
+#define WIFI_PASSWORD "cocoelle"
+// MQTT
+#define PORT  1883
+#define MQTT_CLIENT_ID "clientID"
+#define MQTT_BROKER_IP "192.168.204.71"
+
+
+
+typedef struct {
+    mqtt_client_t* mqtt_client_inst;
+    struct mqtt_connect_client_info_t mqtt_client_info;
+    uint8_t data[MQTT_OUTPUT_RINGBUF_SIZE];
+    uint8_t topic[100];
+    uint32_t len;
+} MQTT_CLIENT_DATA_T;
+
+MQTT_CLIENT_DATA_T *mqtt;
+
+
+
+/* References for this implementation:
+ * raspberry-pi-pico-c-sdk.pdf, Section '4.1.1. hardware_adc'
+ * pico-examples/adc/adc_console/adc_console.c */
+float read_onboard_temperature(const char unit) {
+
+    /* 12-bit conversion, assume max value == ADC_VREF == 3.3 V */
+    const float conversionFactor = 3.3f / (1 << 12);
+
+    float adc = (float)adc_read() * conversionFactor;
+    float tempC = 27.0f - (adc - 0.706f) / 0.001721f;
+
+    if (unit == 'C') {
+        return tempC;
+    } else if (unit == 'F') {
+        return tempC * 9 / 5 + 32;
+    }
+
+    return -1.0f;
+}
+
+void control_led(bool on) {
+    // Public state on /state topic
+    const char* message = on ? "On" : "Off";
+    char state_topic[128];
+    snprintf(state_topic, sizeof(state_topic), "%s/state", mqtt->topic);
+    mqtt_publish(mqtt->mqtt_client_inst, state_topic, message, strlen(message), 0, 0, NULL, NULL);
+}
+
+void publish_temperature() {
+    //Public temperature on /temperature topic
+    float temperature = read_onboard_temperature(TEMPERATURE_UNITS);
+    char temp_str[16];
+    snprintf(temp_str, sizeof(temp_str), "%.2f", temperature);
+    mqtt_publish(mqtt->mqtt_client_inst, "/temperature", temp_str, strlen(temp_str), 0, 0, NULL, NULL);
+}
+static void mqtt_incoming_data_cb(void *arg, const u8_t *data, u16_t len, u8_t flags) {
+    MQTT_CLIENT_DATA_T* mqtt_client = (MQTT_CLIENT_DATA_T*)arg;
+    strncpy(mqtt_client->data, data, len);
+    mqtt_client->len = len;
+    mqtt_client->data[len] = '\0';
+    //Stampo i messaggi e  i topic
+    printf("Topic: %s, Messaggio: %s\n", mqtt_client->topic, mqtt_client->data);
+
+
+    if (strcmp(mqtt->topic, "/led") == 0)
+    {
+        if (strcmp((const char *)mqtt_client->data, "On") == 0)
+            control_led(true);
+        else if  (strcmp((const char *)mqtt_client->data, "Off") == 0)
+            control_led(false);
+    }
+
+}
+
+static void mqtt_incoming_publish_cb(void *arg, const char *topic, u32_t tot_len) {
+    MQTT_CLIENT_DATA_T* mqtt_client = (MQTT_CLIENT_DATA_T*)arg;
+    strcpy(mqtt_client->topic, topic);
+}
+
+static void mqtt_connection_cb(mqtt_client_t *client, void *arg, mqtt_connection_status_t status) {
+    MQTT_CLIENT_DATA_T* mqtt_client = (MQTT_CLIENT_DATA_T*)arg;
+    if (status == MQTT_CONNECT_ACCEPTED) {
+        mqtt_sub_unsub(client, "/temperature", 0, NULL, arg, 1);
+        printf("Connesso al topic /temperature con successo\n");
+    }
+}
+int main() {
+
+    stdio_init_all();
+
+    adc_init();
+    adc_set_temp_sensor_enabled(true);
+    adc_select_input(4);
+
+    mqtt = (MQTT_CLIENT_DATA_T*)calloc(1, sizeof(MQTT_CLIENT_DATA_T));
+    if (!mqtt) {
+        printf("Failed to inizialize MQTT client \n");
+        return 1;
+    }
+    // MQTT CLIENT INFO
+    mqtt->mqtt_client_info.client_id = MQTT_CLIENT_ID;
+    mqtt->mqtt_client_info.keep_alive = 60; // Keep alive in secondi
+
+    if (cyw43_arch_init()) {
+        printf("Failed to inizialize CYW43\n");
+        return 1;
+    }
+
+    cyw43_arch_enable_sta_mode();
+    if (cyw43_arch_wifi_connect_timeout_ms(WIFI_SSID, WIFI_PASSWORD, CYW43_AUTH_WPA2_AES_PSK, 10000)) {
+        printf("Wi-Fi error\n");
+        return 1;
+    }
+    printf("\nConnected to Wifi\n");
+
+    ip_addr_t addr;
+    if (!ip4addr_aton(MQTT_BROKER_IP, &addr)) {
+        printf("MQTT ip Address not valid !\n");
+        return 1;
+    }
+
+    mqtt->mqtt_client_inst = mqtt_client_new();
+    if (!mqtt->mqtt_client_inst) {
+        printf("MQTT client instance creation error\n");
+        return 1;
+    }
+
+    if (mqtt_client_connect(mqtt->mqtt_client_inst, &addr, PORT, mqtt_connection_cb, mqtt, &mqtt->mqtt_client_info) != ERR_OK) {
+        printf("MQTT broker connection error\n");
+        return 1;
+    }
+    printf("Successfully connected to the MQTT broker\n");
+    mqtt_set_inpub_callback(mqtt->mqtt_client_inst, mqtt_incoming_publish_cb, mqtt_incoming_data_cb, mqtt);
+
+    while (1) {
+        publish_temperature(); // Public temperature every 5 sec
+        sleep_ms(5000);
+        tight_loop_contents();
+    }
+
+    return 0;
+}
\ No newline at end of file

From 62c0a139220f7d1cfe6e09b01f3f19da461e95b3 Mon Sep 17 00:00:00 2001
From: ellebi2000 <lorenzobattistelli.2000@gmail.com>
Date: Sat, 25 May 2024 12:59:21 +0200
Subject: [PATCH 02/11] added mqtt pub/sub example

---
 pico_w/CMakeLists.txt                  |  6 +++++
 pico_w/mqtt/CMakeLists.txt             |  8 +++++++
 pico_w/mqtt/mqtt_client/CMakeLists.txt | 31 ++++++++++++++++++++++++++
 pico_w/mqtt/mqtt_client/mqtt_client.c  | 19 ++++++++++------
 4 files changed, 57 insertions(+), 7 deletions(-)

diff --git a/pico_w/CMakeLists.txt b/pico_w/CMakeLists.txt
index f66c02e95..62e08892f 100644
--- a/pico_w/CMakeLists.txt
+++ b/pico_w/CMakeLists.txt
@@ -24,5 +24,11 @@ if (PICO_CYW43_SUPPORTED) # set by PICO_BOARD=pico_w
         else()
             add_subdirectory(bt)
         endif()
+
+        if (NOT TARGET picow_bt_example_no_cyw43_lwip_background)
+            message("Skipping Pico W Mqtt examples as support is not available")
+        else()
+            add_subdirectory(mqtt)
+        endif ()
     endif()
 endif()
diff --git a/pico_w/mqtt/CMakeLists.txt b/pico_w/mqtt/CMakeLists.txt
index e69de29bb..2f018792b 100644
--- a/pico_w/mqtt/CMakeLists.txt
+++ b/pico_w/mqtt/CMakeLists.txt
@@ -0,0 +1,8 @@
+cmake_minimum_required(VERSION 3.12)
+
+project(test_mqtt C CXX ASM)
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_CXX_STANDARD 17)
+
+add_subdirectory(mqtt_client)
+pico_sdk_init()
diff --git a/pico_w/mqtt/mqtt_client/CMakeLists.txt b/pico_w/mqtt/mqtt_client/CMakeLists.txt
index e69de29bb..ff66b2fb4 100644
--- a/pico_w/mqtt/mqtt_client/CMakeLists.txt
+++ b/pico_w/mqtt/mqtt_client/CMakeLists.txt
@@ -0,0 +1,31 @@
+
+
+add_executable(mqttApp
+        mqtt_client.c
+        )
+target_link_libraries(mqttApp
+        pico_stdlib
+        hardware_adc
+        pico_cyw43_arch_lwip_threadsafe_background
+        pico_lwip_mqtt
+)
+# Initialise pico_sdk from installed location
+# (note this can come from environment, CMake cache etc)
+
+set(PICO_BOARD pico_w CACHE STRING "Board type")
+# Pull in Raspberry Pi Pico SDK (must be before project)
+if (PICO_SDK_VERSION_STRING VERSION_LESS "1.4.0")
+    message(FATAL_ERROR "Raspberry Pi Pico SDK version 1.4.0 (or later) required. Your version is ${PICO_SDK_VERSION_STRING}")
+endif()
+# Initialise the Raspberry Pi Pico SDK
+# Add executable. Default name is the project name, version 0.1
+pico_set_program_name(mqttApp "mqttApp")
+pico_set_program_version(mqttApp "0.1")
+pico_enable_stdio_uart(mqttApp 1)
+pico_enable_stdio_usb(mqttApp 1)
+target_include_directories(mqttApp PRIVATE
+        ${CMAKE_CURRENT_LIST_DIR}
+        ${CMAKE_CURRENT_LIST_DIR}/.. # for our common lwipopts or any other standard includes, if required
+)
+
+pico_add_extra_outputs(mqttApp)
\ No newline at end of file
diff --git a/pico_w/mqtt/mqtt_client/mqtt_client.c b/pico_w/mqtt/mqtt_client/mqtt_client.c
index ed94104a9..28d7d3d94 100644
--- a/pico_w/mqtt/mqtt_client/mqtt_client.c
+++ b/pico_w/mqtt/mqtt_client/mqtt_client.c
@@ -13,12 +13,12 @@
 #define TEMPERATURE_UNITS 'C'
 
 // WiFi
-#define WIFI_SSID "Elliot"
-#define WIFI_PASSWORD "cocoelle"
+#define WIFI_SSID "YOUR_WIFI_SSID"
+#define WIFI_PASSWORD "YOUR_WIFI_PASSWD"
 // MQTT
 #define PORT  1883
 #define MQTT_CLIENT_ID "clientID"
-#define MQTT_BROKER_IP "192.168.204.71"
+#define MQTT_BROKER_IP "YOUR_BROKER_IP"
 
 
 
@@ -55,8 +55,13 @@ float read_onboard_temperature(const char unit) {
 }
 
 void control_led(bool on) {
-    // Public state on /state topic
+    // Public state on /state topic and on/off led board
     const char* message = on ? "On" : "Off";
+    if (on)
+        cyw43_arch_gpio_put(CYW43_WL_GPIO_LED_PIN, 1);
+    else
+        cyw43_arch_gpio_put(CYW43_WL_GPIO_LED_PIN, 0);
+
     char state_topic[128];
     snprintf(state_topic, sizeof(state_topic), "%s/state", mqtt->topic);
     mqtt_publish(mqtt->mqtt_client_inst, state_topic, message, strlen(message), 0, 0, NULL, NULL);
@@ -75,7 +80,7 @@ static void mqtt_incoming_data_cb(void *arg, const u8_t *data, u16_t len, u8_t f
     mqtt_client->len = len;
     mqtt_client->data[len] = '\0';
     //Stampo i messaggi e  i topic
-    printf("Topic: %s, Messaggio: %s\n", mqtt_client->topic, mqtt_client->data);
+    printf("Topic: %s, Message: %s\n", mqtt_client->topic, mqtt_client->data);
 
 
     if (strcmp(mqtt->topic, "/led") == 0)
@@ -96,8 +101,8 @@ static void mqtt_incoming_publish_cb(void *arg, const char *topic, u32_t tot_len
 static void mqtt_connection_cb(mqtt_client_t *client, void *arg, mqtt_connection_status_t status) {
     MQTT_CLIENT_DATA_T* mqtt_client = (MQTT_CLIENT_DATA_T*)arg;
     if (status == MQTT_CONNECT_ACCEPTED) {
-        mqtt_sub_unsub(client, "/temperature", 0, NULL, arg, 1);
-        printf("Connesso al topic /temperature con successo\n");
+        mqtt_sub_unsub(client, "/led", 0, NULL, arg, 1);
+        printf("Connected to the /led topic successfully\n");
     }
 }
 int main() {

From f83eefefeb739329ca743b8fe73f51123ad6e96a Mon Sep 17 00:00:00 2001
From: ellebi2000 <lorenzobattistelli2000@gmail.com>
Date: Sun, 2 Jun 2024 13:42:52 +0200
Subject: [PATCH 03/11] removed unnecessary comments

---
 pico_w/mqtt/mqtt_client/CMakeLists.txt | 5 +----
 pico_w/mqtt/mqtt_client/mqtt_client.c  | 6 ++----
 2 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/pico_w/mqtt/mqtt_client/CMakeLists.txt b/pico_w/mqtt/mqtt_client/CMakeLists.txt
index ff66b2fb4..fda9fcb2d 100644
--- a/pico_w/mqtt/mqtt_client/CMakeLists.txt
+++ b/pico_w/mqtt/mqtt_client/CMakeLists.txt
@@ -9,16 +9,13 @@ target_link_libraries(mqttApp
         pico_cyw43_arch_lwip_threadsafe_background
         pico_lwip_mqtt
 )
-# Initialise pico_sdk from installed location
-# (note this can come from environment, CMake cache etc)
 
 set(PICO_BOARD pico_w CACHE STRING "Board type")
 # Pull in Raspberry Pi Pico SDK (must be before project)
 if (PICO_SDK_VERSION_STRING VERSION_LESS "1.4.0")
     message(FATAL_ERROR "Raspberry Pi Pico SDK version 1.4.0 (or later) required. Your version is ${PICO_SDK_VERSION_STRING}")
 endif()
-# Initialise the Raspberry Pi Pico SDK
-# Add executable. Default name is the project name, version 0.1
+
 pico_set_program_name(mqttApp "mqttApp")
 pico_set_program_version(mqttApp "0.1")
 pico_enable_stdio_uart(mqttApp 1)
diff --git a/pico_w/mqtt/mqtt_client/mqtt_client.c b/pico_w/mqtt/mqtt_client/mqtt_client.c
index 28d7d3d94..0441d44dc 100644
--- a/pico_w/mqtt/mqtt_client/mqtt_client.c
+++ b/pico_w/mqtt/mqtt_client/mqtt_client.c
@@ -79,9 +79,8 @@ static void mqtt_incoming_data_cb(void *arg, const u8_t *data, u16_t len, u8_t f
     strncpy(mqtt_client->data, data, len);
     mqtt_client->len = len;
     mqtt_client->data[len] = '\0';
-    //Stampo i messaggi e  i topic
-    printf("Topic: %s, Message: %s\n", mqtt_client->topic, mqtt_client->data);
 
+    printf("Topic: %s, Message: %s\n", mqtt_client->topic, mqtt_client->data);
 
     if (strcmp(mqtt->topic, "/led") == 0)
     {
@@ -90,7 +89,6 @@ static void mqtt_incoming_data_cb(void *arg, const u8_t *data, u16_t len, u8_t f
         else if  (strcmp((const char *)mqtt_client->data, "Off") == 0)
             control_led(false);
     }
-
 }
 
 static void mqtt_incoming_publish_cb(void *arg, const char *topic, u32_t tot_len) {
@@ -120,7 +118,7 @@ int main() {
     }
     // MQTT CLIENT INFO
     mqtt->mqtt_client_info.client_id = MQTT_CLIENT_ID;
-    mqtt->mqtt_client_info.keep_alive = 60; // Keep alive in secondi
+    mqtt->mqtt_client_info.keep_alive = 60; // Keep alive in sec
 
     if (cyw43_arch_init()) {
         printf("Failed to inizialize CYW43\n");

From 04f621fb7fd22a9deaf35cb1cbd741d258fe2f5e Mon Sep 17 00:00:00 2001
From: Peter Harper <peter.harper@raspberrypi.com>
Date: Wed, 29 Jan 2025 15:02:19 +0000
Subject: [PATCH 04/11] Move mqtt example to wifi folder

---
 pico_w/CMakeLists.txt                             | 6 ------
 pico_w/wifi/CMakeLists.txt                        | 1 +
 pico_w/{ => wifi}/mqtt/CMakeLists.txt             | 0
 pico_w/{ => wifi}/mqtt/mqtt_client/CMakeLists.txt | 0
 pico_w/{ => wifi}/mqtt/mqtt_client/lwipopts.h     | 0
 pico_w/{ => wifi}/mqtt/mqtt_client/mqtt_client.c  | 0
 6 files changed, 1 insertion(+), 6 deletions(-)
 rename pico_w/{ => wifi}/mqtt/CMakeLists.txt (100%)
 rename pico_w/{ => wifi}/mqtt/mqtt_client/CMakeLists.txt (100%)
 rename pico_w/{ => wifi}/mqtt/mqtt_client/lwipopts.h (100%)
 rename pico_w/{ => wifi}/mqtt/mqtt_client/mqtt_client.c (100%)

diff --git a/pico_w/CMakeLists.txt b/pico_w/CMakeLists.txt
index 62e08892f..f66c02e95 100644
--- a/pico_w/CMakeLists.txt
+++ b/pico_w/CMakeLists.txt
@@ -24,11 +24,5 @@ if (PICO_CYW43_SUPPORTED) # set by PICO_BOARD=pico_w
         else()
             add_subdirectory(bt)
         endif()
-
-        if (NOT TARGET picow_bt_example_no_cyw43_lwip_background)
-            message("Skipping Pico W Mqtt examples as support is not available")
-        else()
-            add_subdirectory(mqtt)
-        endif ()
     endif()
 endif()
diff --git a/pico_w/wifi/CMakeLists.txt b/pico_w/wifi/CMakeLists.txt
index 4599a21cd..31797084b 100644
--- a/pico_w/wifi/CMakeLists.txt
+++ b/pico_w/wifi/CMakeLists.txt
@@ -18,6 +18,7 @@ else()
     add_subdirectory_exclude_platforms(tcp_server)
     add_subdirectory_exclude_platforms(udp_beacon)
     add_subdirectory_exclude_platforms(http_client)
+    add_subdirectory_exclude_platforms(mqtt)
 
     if (NOT PICO_MBEDTLS_PATH)
         message("Skipping tls examples as PICO_MBEDTLS_PATH is not defined")
diff --git a/pico_w/mqtt/CMakeLists.txt b/pico_w/wifi/mqtt/CMakeLists.txt
similarity index 100%
rename from pico_w/mqtt/CMakeLists.txt
rename to pico_w/wifi/mqtt/CMakeLists.txt
diff --git a/pico_w/mqtt/mqtt_client/CMakeLists.txt b/pico_w/wifi/mqtt/mqtt_client/CMakeLists.txt
similarity index 100%
rename from pico_w/mqtt/mqtt_client/CMakeLists.txt
rename to pico_w/wifi/mqtt/mqtt_client/CMakeLists.txt
diff --git a/pico_w/mqtt/mqtt_client/lwipopts.h b/pico_w/wifi/mqtt/mqtt_client/lwipopts.h
similarity index 100%
rename from pico_w/mqtt/mqtt_client/lwipopts.h
rename to pico_w/wifi/mqtt/mqtt_client/lwipopts.h
diff --git a/pico_w/mqtt/mqtt_client/mqtt_client.c b/pico_w/wifi/mqtt/mqtt_client/mqtt_client.c
similarity index 100%
rename from pico_w/mqtt/mqtt_client/mqtt_client.c
rename to pico_w/wifi/mqtt/mqtt_client/mqtt_client.c

From e239bc4d23ad91447b5429431499bd4d64197e3f Mon Sep 17 00:00:00 2001
From: Peter Harper <peter.harper@raspberrypi.com>
Date: Wed, 29 Jan 2025 17:06:56 +0000
Subject: [PATCH 05/11] Tidy up mqtt example

Fix review comments and build warnings.
Use MQTT_SERVER build variable instead of hard coding IP address.
Make a DNS request for the server.
Use async timer for publishing the temperature.
---
 pico_w/wifi/mqtt/mqtt_client/CMakeLists.txt |  41 +++--
 pico_w/wifi/mqtt/mqtt_client/README         |  33 ++++
 pico_w/wifi/mqtt/mqtt_client/lwipopts.h     |  92 +---------
 pico_w/wifi/mqtt/mqtt_client/mqtt_client.c  | 193 ++++++++++++--------
 4 files changed, 181 insertions(+), 178 deletions(-)
 create mode 100644 pico_w/wifi/mqtt/mqtt_client/README

diff --git a/pico_w/wifi/mqtt/mqtt_client/CMakeLists.txt b/pico_w/wifi/mqtt/mqtt_client/CMakeLists.txt
index fda9fcb2d..3846ddd4f 100644
--- a/pico_w/wifi/mqtt/mqtt_client/CMakeLists.txt
+++ b/pico_w/wifi/mqtt/mqtt_client/CMakeLists.txt
@@ -1,28 +1,35 @@
+# Define the host name of the MQTT server in an environment variable or pass it to cmake,
+# e.g. cmake -DMQTT_SERVER=myserver ..
 
+if (DEFINED ENV{MQTT_SERVER} AND (NOT MQTT_SERVER))
+    set(MQTT_SERVER $ENV{MQTT_SERVER})
+    message("Using MQTT_SERVER from environment ('${MQTT_SERVER}')")
+endif()
+if (NOT MQTT_SERVER)
+    return()
+endif()
+
+# Define the name of an MQTT broker/server to enable this example
+set(MQTT_SERVER "${MQTT_SERVER}" CACHE INTERNAL "MQTT server for examples")
 
-add_executable(mqttApp
+set(TARGET_NAME mqtt_client)
+
+add_executable(${TARGET_NAME}
         mqtt_client.c
         )
-target_link_libraries(mqttApp
+target_link_libraries(${TARGET_NAME}
         pico_stdlib
         hardware_adc
         pico_cyw43_arch_lwip_threadsafe_background
         pico_lwip_mqtt
 )
-
-set(PICO_BOARD pico_w CACHE STRING "Board type")
-# Pull in Raspberry Pi Pico SDK (must be before project)
-if (PICO_SDK_VERSION_STRING VERSION_LESS "1.4.0")
-    message(FATAL_ERROR "Raspberry Pi Pico SDK version 1.4.0 (or later) required. Your version is ${PICO_SDK_VERSION_STRING}")
-endif()
-
-pico_set_program_name(mqttApp "mqttApp")
-pico_set_program_version(mqttApp "0.1")
-pico_enable_stdio_uart(mqttApp 1)
-pico_enable_stdio_usb(mqttApp 1)
-target_include_directories(mqttApp PRIVATE
+target_include_directories(${TARGET_NAME} PRIVATE
         ${CMAKE_CURRENT_LIST_DIR}
-        ${CMAKE_CURRENT_LIST_DIR}/.. # for our common lwipopts or any other standard includes, if required
+        ${CMAKE_CURRENT_LIST_DIR}/../.. # for our common lwipopts or any other standard includes, if required
 )
-
-pico_add_extra_outputs(mqttApp)
\ No newline at end of file
+target_compile_definitions(${TARGET_NAME} PRIVATE
+        WIFI_SSID=\"${WIFI_SSID}\"
+        WIFI_PASSWORD=\"${WIFI_PASSWORD}\"
+        MQTT_SERVER=\"${MQTT_SERVER}\"
+        )
+pico_add_extra_outputs(${TARGET_NAME})
diff --git a/pico_w/wifi/mqtt/mqtt_client/README b/pico_w/wifi/mqtt/mqtt_client/README
new file mode 100644
index 000000000..4886a4b1c
--- /dev/null
+++ b/pico_w/wifi/mqtt/mqtt_client/README
@@ -0,0 +1,33 @@
+To use this example you will need to install an MQTT server on your network.
+To install the Mosquitto MQTT client on a Raspberry Pi Linux device run the following...
+
+sudo apt install mosquitto
+sudo apt install mosquitto-clients
+
+Check it works...
+
+mosquitto_pub -t test_topic -m "Yes it works" -r
+mosquitto_sub -t test_topic -C 1
+
+To allow an external client to connect to the server you will have to change the configuration. Add the following to /etc/mosquitto/conf.d/mosquitto.conf
+
+allow_anonymous true
+listener 1883 0.0.0.0
+
+Then restart the service.
+
+sudo service mosquitto restart
+
+When building the code set the host name of the MQTT server, e.g.
+
+export MQTT_SERVER=myhost
+cmake ..
+
+The example should publish its core temperature to the /temperature topic. You can subscribe to this topic from another machine.
+
+mosquitto_sub -h $MQTT_SERVER -t '/temperature'
+
+You can turn the led on and off by publishing messages.
+
+mosquitto_pub -h $MQTT_SERVER -t '/led' -m on
+mosquitto_pub -h $MQTT_SERVER -t '/led' -m off
diff --git a/pico_w/wifi/mqtt/mqtt_client/lwipopts.h b/pico_w/wifi/mqtt/mqtt_client/lwipopts.h
index 9e71835b9..e4817116f 100644
--- a/pico_w/wifi/mqtt/mqtt_client/lwipopts.h
+++ b/pico_w/wifi/mqtt/mqtt_client/lwipopts.h
@@ -1,90 +1,12 @@
-#ifndef _LWIPOPTS_EXAMPLE_COMMONH_H
-#define _LWIPOPTS_EXAMPLE_COMMONH_H
+#ifndef _LWIPOPTS_H
+#define _LWIPOPTS_H
 
+// Generally you would define your own explicit list of lwIP options
+// (see https://www.nongnu.org/lwip/2_1_x/group__lwip__opts.html)
+//
+// This example uses a common include to avoid repetition
+#include "lwipopts_examples_common.h"
 
-// Common settings used in most of the pico_w examples
-// (see https://www.nongnu.org/lwip/2_1_x/group__lwip__opts.html for details)
-
-// allow override in some examples
-#ifndef NO_SYS
-#define NO_SYS                      1
-#endif
-// allow override in some examples
-#ifndef LWIP_SOCKET
-#define LWIP_SOCKET                 0
-#endif
-#if PICO_CYW43_ARCH_POLL
-#define MEM_LIBC_MALLOC             1
-#else
-// MEM_LIBC_MALLOC is incompatible with non polling versions
-#define MEM_LIBC_MALLOC             0
-#endif
-#define MEM_ALIGNMENT               4
-#define MEM_SIZE                    4000
 #define MEMP_NUM_SYS_TIMEOUT        (LWIP_NUM_SYS_TIMEOUT_INTERNAL+1)
-#define MEMP_NUM_TCP_SEG            32
-#define MEMP_NUM_ARP_QUEUE          10
-#define PBUF_POOL_SIZE              24
-#define LWIP_ARP                    1
-#define LWIP_ETHERNET               1
-#define LWIP_ICMP                   1
-#define LWIP_RAW                    1
-#define TCP_WND                     (8 * TCP_MSS)
-#define TCP_MSS                     1460
-#define TCP_SND_BUF                 (8 * TCP_MSS)
-#define TCP_SND_QUEUELEN            ((4 * (TCP_SND_BUF) + (TCP_MSS - 1)) / (TCP_MSS))
-#define LWIP_NETIF_STATUS_CALLBACK  1
-#define LWIP_NETIF_LINK_CALLBACK    1
-#define LWIP_NETIF_HOSTNAME         1
-#define LWIP_NETCONN                0
-#define MEM_STATS                   0
-#define SYS_STATS                   0
-#define MEMP_STATS                  0
-#define LINK_STATS                  0
-// #define ETH_PAD_SIZE                2
-#define LWIP_CHKSUM_ALGORITHM       3
-#define LWIP_DHCP                   1
-#define LWIP_IPV4                   1
-#define LWIP_TCP                    1
-#define LWIP_UDP                    1
-#define LWIP_DNS                    1
-#define LWIP_TCP_KEEPALIVE          1
-#define LWIP_NETIF_TX_SINGLE_PBUF   1
-#define DHCP_DOES_ARP_CHECK         0
-#define LWIP_DHCP_DOES_ACD_CHECK    0
 
-#ifndef NDEBUG
-#define LWIP_DEBUG                  1
-#define LWIP_STATS                  1
-#define LWIP_STATS_DISPLAY          1
 #endif
-
-#define ETHARP_DEBUG                LWIP_DBG_OFF
-#define NETIF_DEBUG                 LWIP_DBG_OFF
-#define PBUF_DEBUG                  LWIP_DBG_OFF
-#define API_LIB_DEBUG               LWIP_DBG_OFF
-#define API_MSG_DEBUG               LWIP_DBG_OFF
-#define SOCKETS_DEBUG               LWIP_DBG_OFF
-#define ICMP_DEBUG                  LWIP_DBG_OFF
-#define INET_DEBUG                  LWIP_DBG_OFF
-#define IP_DEBUG                    LWIP_DBG_OFF
-#define IP_REASS_DEBUG              LWIP_DBG_OFF
-#define RAW_DEBUG                   LWIP_DBG_OFF
-#define MEM_DEBUG                   LWIP_DBG_OFF
-#define MEMP_DEBUG                  LWIP_DBG_OFF
-#define SYS_DEBUG                   LWIP_DBG_OFF
-#define TCP_DEBUG                   LWIP_DBG_OFF
-#define TCP_INPUT_DEBUG             LWIP_DBG_OFF
-#define TCP_OUTPUT_DEBUG            LWIP_DBG_OFF
-#define TCP_RTO_DEBUG               LWIP_DBG_OFF
-#define TCP_CWND_DEBUG              LWIP_DBG_OFF
-#define TCP_WND_DEBUG               LWIP_DBG_OFF
-#define TCP_FR_DEBUG                LWIP_DBG_OFF
-#define TCP_QLEN_DEBUG              LWIP_DBG_OFF
-#define TCP_RST_DEBUG               LWIP_DBG_OFF
-#define UDP_DEBUG                   LWIP_DBG_OFF
-#define TCPIP_DEBUG                 LWIP_DBG_OFF
-#define PPP_DEBUG                   LWIP_DBG_OFF
-#define SLIP_DEBUG                  LWIP_DBG_OFF
-#define DHCP_DEBUG                  LWIP_DBG_OFF
-#endif /* __LWIPOPTS_H__ */
\ No newline at end of file
diff --git a/pico_w/wifi/mqtt/mqtt_client/mqtt_client.c b/pico_w/wifi/mqtt/mqtt_client/mqtt_client.c
index 0441d44dc..c7ae9a926 100644
--- a/pico_w/wifi/mqtt/mqtt_client/mqtt_client.c
+++ b/pico_w/wifi/mqtt/mqtt_client/mqtt_client.c
@@ -1,43 +1,48 @@
+/**
+ * Copyright (c) 2022 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
 //
 // Created by elliot on 25/05/24.
 //
 #include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include "pico/unique_id.h"
 #include "hardware/gpio.h"
 #include "hardware/irq.h"
 #include "hardware/adc.h"
-#include "pico/cyw43_arch.h"
 #include "lwip/apps/mqtt.h"
-
+#include "lwip/dns.h"
 
 // Temperature
-#define TEMPERATURE_UNITS 'C'
-
-// WiFi
-#define WIFI_SSID "YOUR_WIFI_SSID"
-#define WIFI_PASSWORD "YOUR_WIFI_PASSWD"
-// MQTT
-#define PORT  1883
-#define MQTT_CLIENT_ID "clientID"
-#define MQTT_BROKER_IP "YOUR_BROKER_IP"
+#ifndef TEMPERATURE_UNITS
+#define TEMPERATURE_UNITS 'C' // Set to 'F' for Fahrenheit
+#endif
 
+#ifndef MQTT_SERVER
+#error Need to define MQTT_SERVER
+#endif
 
+// MQTT parameters
+#ifndef MQTT_PORT
+#define MQTT_PORT 1883
+#endif
 
 typedef struct {
     mqtt_client_t* mqtt_client_inst;
     struct mqtt_connect_client_info_t mqtt_client_info;
-    uint8_t data[MQTT_OUTPUT_RINGBUF_SIZE];
-    uint8_t topic[100];
+    char data[MQTT_OUTPUT_RINGBUF_SIZE];
+    char topic[100];
     uint32_t len;
+    ip_addr_t mqtt_server_address;
 } MQTT_CLIENT_DATA_T;
 
-MQTT_CLIENT_DATA_T *mqtt;
-
-
-
 /* References for this implementation:
  * raspberry-pi-pico-c-sdk.pdf, Section '4.1.1. hardware_adc'
  * pico-examples/adc/adc_console/adc_console.c */
-float read_onboard_temperature(const char unit) {
+static float read_onboard_temperature(const char unit) {
 
     /* 12-bit conversion, assume max value == ADC_VREF == 3.3 V */
     const float conversionFactor = 3.3f / (1 << 12);
@@ -45,7 +50,7 @@ float read_onboard_temperature(const char unit) {
     float adc = (float)adc_read() * conversionFactor;
     float tempC = 27.0f - (adc - 0.706f) / 0.001721f;
 
-    if (unit == 'C') {
+    if (unit == 'C' || unit != 'F') {
         return tempC;
     } else if (unit == 'F') {
         return tempC * 9 / 5 + 32;
@@ -54,8 +59,8 @@ float read_onboard_temperature(const char unit) {
     return -1.0f;
 }
 
-void control_led(bool on) {
-    // Public state on /state topic and on/off led board
+static void control_led(MQTT_CLIENT_DATA_T *state, bool on) {
+    // Publish state on /state topic and on/off led board
     const char* message = on ? "On" : "Off";
     if (on)
         cyw43_arch_gpio_put(CYW43_WL_GPIO_LED_PIN, 1);
@@ -63,99 +68,135 @@ void control_led(bool on) {
         cyw43_arch_gpio_put(CYW43_WL_GPIO_LED_PIN, 0);
 
     char state_topic[128];
-    snprintf(state_topic, sizeof(state_topic), "%s/state", mqtt->topic);
-    mqtt_publish(mqtt->mqtt_client_inst, state_topic, message, strlen(message), 0, 0, NULL, NULL);
+    snprintf(state_topic, sizeof(state_topic), "%s/state", state->topic);
+    mqtt_publish(state->mqtt_client_inst, state_topic, message, strlen(message), 0, 0, NULL, NULL);
 }
 
-void publish_temperature() {
-    //Public temperature on /temperature topic
+static void publish_temperature(MQTT_CLIENT_DATA_T *state) {
+    static float old_temperature;
+    const char temperature_key[] = "/temperature";
     float temperature = read_onboard_temperature(TEMPERATURE_UNITS);
-    char temp_str[16];
-    snprintf(temp_str, sizeof(temp_str), "%.2f", temperature);
-    mqtt_publish(mqtt->mqtt_client_inst, "/temperature", temp_str, strlen(temp_str), 0, 0, NULL, NULL);
+    if (temperature != old_temperature) {
+        old_temperature = temperature;
+        // Publish temperature on /temperature topic
+        char temp_str[16];
+        snprintf(temp_str, sizeof(temp_str), "%.2f", temperature);
+        printf("Publishing %s to %s\n", temp_str, temperature_key);
+        mqtt_publish(state->mqtt_client_inst, temperature_key, temp_str, strlen(temp_str), 0, 0, NULL, NULL);
+    }
 }
+
 static void mqtt_incoming_data_cb(void *arg, const u8_t *data, u16_t len, u8_t flags) {
-    MQTT_CLIENT_DATA_T* mqtt_client = (MQTT_CLIENT_DATA_T*)arg;
-    strncpy(mqtt_client->data, data, len);
-    mqtt_client->len = len;
-    mqtt_client->data[len] = '\0';
+    MQTT_CLIENT_DATA_T* state = (MQTT_CLIENT_DATA_T*)arg;
+    strncpy(state->data, (const char *)data, len);
+    state->len = len;
+    state->data[len] = '\0';
 
-    printf("Topic: %s, Message: %s\n", mqtt_client->topic, mqtt_client->data);
+    printf("Topic: %s, Message: %s\n", state->topic, state->data);
 
-    if (strcmp(mqtt->topic, "/led") == 0)
+    if (strcmp(state->topic, "/led") == 0)
     {
-        if (strcmp((const char *)mqtt_client->data, "On") == 0)
-            control_led(true);
-        else if  (strcmp((const char *)mqtt_client->data, "Off") == 0)
-            control_led(false);
+        if (lwip_stricmp((const char *)state->data, "On") == 0)
+            control_led(state, true);
+        else if  (lwip_stricmp((const char *)state->data, "Off") == 0)
+            control_led(state, false);
     }
 }
 
 static void mqtt_incoming_publish_cb(void *arg, const char *topic, u32_t tot_len) {
     MQTT_CLIENT_DATA_T* mqtt_client = (MQTT_CLIENT_DATA_T*)arg;
-    strcpy(mqtt_client->topic, topic);
+    strncpy(mqtt_client->topic, topic, sizeof(mqtt_client->topic));
 }
 
+static void temperature_worker_fn(async_context_t *context, async_at_time_worker_t *worker) {
+    MQTT_CLIENT_DATA_T* state = (MQTT_CLIENT_DATA_T*)worker->user_data;
+    publish_temperature(state);
+    async_context_add_at_time_worker_in_ms(context, worker, 10000); // repeat in 10s
+}
+static async_at_time_worker_t temperature_worker = { .do_work = temperature_worker_fn };
+
 static void mqtt_connection_cb(mqtt_client_t *client, void *arg, mqtt_connection_status_t status) {
-    MQTT_CLIENT_DATA_T* mqtt_client = (MQTT_CLIENT_DATA_T*)arg;
     if (status == MQTT_CONNECT_ACCEPTED) {
         mqtt_sub_unsub(client, "/led", 0, NULL, arg, 1);
         printf("Connected to the /led topic successfully\n");
+
+        // Publish temperature every 10 sec if it's changed
+        temperature_worker.user_data = arg;
+        async_context_add_at_time_worker_in_ms(cyw43_arch_async_context(), &temperature_worker, 0);
+    } else {
+        panic("Unexpected status");
     }
 }
-int main() {
 
+static void start_client(MQTT_CLIENT_DATA_T *state) {
+    state->mqtt_client_inst = mqtt_client_new();
+    if (!state->mqtt_client_inst) {
+        panic("MQTT client instance creation error");
+    }
+    printf("IP address of this device %s\n", ipaddr_ntoa(&(netif_list->ip_addr)));
+    printf("Connecting to mqtt server at %s\n", ipaddr_ntoa(&state->mqtt_server_address));
+
+    cyw43_arch_lwip_begin();
+    if (mqtt_client_connect(state->mqtt_client_inst, &state->mqtt_server_address, MQTT_PORT, mqtt_connection_cb, state, &state->mqtt_client_info) != ERR_OK) {
+        panic("MQTT broker connection error");
+    }
+    mqtt_set_inpub_callback(state->mqtt_client_inst, mqtt_incoming_publish_cb, mqtt_incoming_data_cb, state);
+    cyw43_arch_lwip_end();
+}
+
+// Call back with a DNS result
+static void dns_found(const char *hostname, const ip_addr_t *ipaddr, void *arg) {
+    MQTT_CLIENT_DATA_T *state = (MQTT_CLIENT_DATA_T*)arg;
+    if (ipaddr) {
+        state->mqtt_server_address = *ipaddr;
+        start_client(state);
+    } else {
+        panic("dns request failed");
+    }
+}
+
+int main(void) {
     stdio_init_all();
 
     adc_init();
     adc_set_temp_sensor_enabled(true);
     adc_select_input(4);
 
-    mqtt = (MQTT_CLIENT_DATA_T*)calloc(1, sizeof(MQTT_CLIENT_DATA_T));
-    if (!mqtt) {
-        printf("Failed to inizialize MQTT client \n");
-        return 1;
-    }
-    // MQTT CLIENT INFO
-    mqtt->mqtt_client_info.client_id = MQTT_CLIENT_ID;
-    mqtt->mqtt_client_info.keep_alive = 60; // Keep alive in sec
+    static MQTT_CLIENT_DATA_T state;
+
+    // Use board unique id for the client id
+    static char client_id_buf[PICO_UNIQUE_BOARD_ID_SIZE_BYTES * 2 + 1];
+    pico_get_unique_board_id_string(client_id_buf, sizeof(client_id_buf));
+    state.mqtt_client_info.client_id = client_id_buf;
+    state.mqtt_client_info.keep_alive = 60; // Keep alive in sec
 
     if (cyw43_arch_init()) {
-        printf("Failed to inizialize CYW43\n");
-        return 1;
+        panic("Failed to inizialize CYW43");
     }
 
     cyw43_arch_enable_sta_mode();
-    if (cyw43_arch_wifi_connect_timeout_ms(WIFI_SSID, WIFI_PASSWORD, CYW43_AUTH_WPA2_AES_PSK, 10000)) {
-        printf("Wi-Fi error\n");
-        return 1;
+    if (cyw43_arch_wifi_connect_timeout_ms(WIFI_SSID, WIFI_PASSWORD, CYW43_AUTH_WPA2_AES_PSK, 30000)) {
+        panic("Failed to connect");
     }
     printf("\nConnected to Wifi\n");
 
-    ip_addr_t addr;
-    if (!ip4addr_aton(MQTT_BROKER_IP, &addr)) {
-        printf("MQTT ip Address not valid !\n");
-        return 1;
-    }
-
-    mqtt->mqtt_client_inst = mqtt_client_new();
-    if (!mqtt->mqtt_client_inst) {
-        printf("MQTT client instance creation error\n");
-        return 1;
+    // We are not in a callback so locking is needed when calling lwip
+    // Make a DNS request for the MQTT server IP address
+    cyw43_arch_lwip_begin();
+    int err = dns_gethostbyname(MQTT_SERVER, &state.mqtt_server_address, dns_found, &state);
+    cyw43_arch_lwip_end();
+
+    if (err == ERR_OK) {
+        // We have the address, just start the client
+        start_client(&state);
+    } else if (err != ERR_INPROGRESS) { // ERR_INPROGRESS means expect a callback
+        panic("dns request failed");
     }
 
-    if (mqtt_client_connect(mqtt->mqtt_client_inst, &addr, PORT, mqtt_connection_cb, mqtt, &mqtt->mqtt_client_info) != ERR_OK) {
-        printf("MQTT broker connection error\n");
-        return 1;
-    }
-    printf("Successfully connected to the MQTT broker\n");
-    mqtt_set_inpub_callback(mqtt->mqtt_client_inst, mqtt_incoming_publish_cb, mqtt_incoming_data_cb, mqtt);
-
-    while (1) {
-        publish_temperature(); // Public temperature every 5 sec
-        sleep_ms(5000);
-        tight_loop_contents();
+    while (true) {
+        cyw43_arch_poll();
+        cyw43_arch_wait_for_work_until(make_timeout_time_ms(10000));
     }
 
     return 0;
-}
\ No newline at end of file
+}

From 90e64d8d840dadbfeacc686d5f35ec7f1c78b0f3 Mon Sep 17 00:00:00 2001
From: Peter Harper <peter.harper@raspberrypi.com>
Date: Wed, 29 Jan 2025 18:16:26 +0000
Subject: [PATCH 06/11] Add support for username and password

---
 pico_w/wifi/mqtt/mqtt_client/CMakeLists.txt | 38 ++++++++++++++-------
 pico_w/wifi/mqtt/mqtt_client/README         | 27 +++++++++++++++
 pico_w/wifi/mqtt/mqtt_client/mqtt_client.c  |  7 ++++
 3 files changed, 60 insertions(+), 12 deletions(-)

diff --git a/pico_w/wifi/mqtt/mqtt_client/CMakeLists.txt b/pico_w/wifi/mqtt/mqtt_client/CMakeLists.txt
index 3846ddd4f..c2ea20927 100644
--- a/pico_w/wifi/mqtt/mqtt_client/CMakeLists.txt
+++ b/pico_w/wifi/mqtt/mqtt_client/CMakeLists.txt
@@ -8,6 +8,14 @@ endif()
 if (NOT MQTT_SERVER)
     return()
 endif()
+if (DEFINED ENV{MQTT_USERNAME} AND (NOT MQTT_USERNAME))
+    set(MQTT_USERNAME $ENV{MQTT_USERNAME})
+    message("Using MQTT_USERNAME from environment ('${MQTT_USERNAME}')")
+endif()
+if (DEFINED ENV{MQTT_PASSWORD} AND (NOT MQTT_PASSWORD))
+    set(MQTT_PASSWORD $ENV{MQTT_PASSWORD})
+    message("Using MQTT_PASSWORD from environment")
+endif()
 
 # Define the name of an MQTT broker/server to enable this example
 set(MQTT_SERVER "${MQTT_SERVER}" CACHE INTERNAL "MQTT server for examples")
@@ -15,21 +23,27 @@ set(MQTT_SERVER "${MQTT_SERVER}" CACHE INTERNAL "MQTT server for examples")
 set(TARGET_NAME mqtt_client)
 
 add_executable(${TARGET_NAME}
-        mqtt_client.c
-        )
+    mqtt_client.c
+)
 target_link_libraries(${TARGET_NAME}
-        pico_stdlib
-        hardware_adc
-        pico_cyw43_arch_lwip_threadsafe_background
-        pico_lwip_mqtt
+    pico_stdlib
+    hardware_adc
+    pico_cyw43_arch_lwip_threadsafe_background
+    pico_lwip_mqtt
 )
 target_include_directories(${TARGET_NAME} PRIVATE
-        ${CMAKE_CURRENT_LIST_DIR}
-        ${CMAKE_CURRENT_LIST_DIR}/../.. # for our common lwipopts or any other standard includes, if required
+    ${CMAKE_CURRENT_LIST_DIR}
+    ${CMAKE_CURRENT_LIST_DIR}/../.. # for our common lwipopts or any other standard includes, if required
 )
 target_compile_definitions(${TARGET_NAME} PRIVATE
-        WIFI_SSID=\"${WIFI_SSID}\"
-        WIFI_PASSWORD=\"${WIFI_PASSWORD}\"
-        MQTT_SERVER=\"${MQTT_SERVER}\"
-        )
+    WIFI_SSID=\"${WIFI_SSID}\"
+    WIFI_PASSWORD=\"${WIFI_PASSWORD}\"
+    MQTT_SERVER=\"${MQTT_SERVER}\"
+)
+if (MQTT_USERNAME AND MQTT_PASSWORD)
+    target_compile_definitions(${TARGET_NAME} PRIVATE
+        MQTT_USERNAME=\"${MQTT_USERNAME}\"
+        MQTT_PASSWORD=\"${MQTT_PASSWORD}\"
+    )
+endif()
 pico_add_extra_outputs(${TARGET_NAME})
diff --git a/pico_w/wifi/mqtt/mqtt_client/README b/pico_w/wifi/mqtt/mqtt_client/README
index 4886a4b1c..b4c124f2f 100644
--- a/pico_w/wifi/mqtt/mqtt_client/README
+++ b/pico_w/wifi/mqtt/mqtt_client/README
@@ -1,33 +1,60 @@
+# Quick start
+
 To use this example you will need to install an MQTT server on your network.
 To install the Mosquitto MQTT client on a Raspberry Pi Linux device run the following...
 
+```
 sudo apt install mosquitto
 sudo apt install mosquitto-clients
+```
 
 Check it works...
 
+```
 mosquitto_pub -t test_topic -m "Yes it works" -r
 mosquitto_sub -t test_topic -C 1
+```
 
 To allow an external client to connect to the server you will have to change the configuration. Add the following to /etc/mosquitto/conf.d/mosquitto.conf
 
+```
 allow_anonymous true
 listener 1883 0.0.0.0
+```
 
 Then restart the service.
 
+```
 sudo service mosquitto restart
+```
 
 When building the code set the host name of the MQTT server, e.g.
 
+```
 export MQTT_SERVER=myhost
 cmake ..
+```
 
 The example should publish its core temperature to the /temperature topic. You can subscribe to this topic from another machine.
 
+```
 mosquitto_sub -h $MQTT_SERVER -t '/temperature'
+```
 
 You can turn the led on and off by publishing messages.
 
+```
 mosquitto_pub -h $MQTT_SERVER -t '/led' -m on
 mosquitto_pub -h $MQTT_SERVER -t '/led' -m off
+```
+
+# Security
+
+If your server has a username and password, you can set these with the following variables.
+
+```
+export MQTT_USERNAME=user
+export MQTT_PASSWORD=pass
+```
+
+Be aware that these details are sent in plain text unless you use TLS.
diff --git a/pico_w/wifi/mqtt/mqtt_client/mqtt_client.c b/pico_w/wifi/mqtt/mqtt_client/mqtt_client.c
index c7ae9a926..43acd700c 100644
--- a/pico_w/wifi/mqtt/mqtt_client/mqtt_client.c
+++ b/pico_w/wifi/mqtt/mqtt_client/mqtt_client.c
@@ -169,6 +169,13 @@ int main(void) {
     pico_get_unique_board_id_string(client_id_buf, sizeof(client_id_buf));
     state.mqtt_client_info.client_id = client_id_buf;
     state.mqtt_client_info.keep_alive = 60; // Keep alive in sec
+#if defined(MQTT_USERNAME) && defined(MQTT_PASSWORD)
+    state.mqtt_client_info.client_user = MQTT_USERNAME;
+    state.mqtt_client_info.client_pass = MQTT_PASSWORD;
+#else
+    state.mqtt_client_info.client_user = NULL;
+    state.mqtt_client_info.client_pass = NULL;
+#endif
 
     if (cyw43_arch_init()) {
         panic("Failed to inizialize CYW43");

From d50294d2aca964450326bb8e2245bd07e3a7bf22 Mon Sep 17 00:00:00 2001
From: Peter Harper <peter.harper@raspberrypi.com>
Date: Wed, 29 Jan 2025 19:29:26 +0000
Subject: [PATCH 07/11] Add TLS support

Move the code down one level
---
 pico_w/wifi/lwipopts_examples_common.h        |  2 +
 pico_w/wifi/mqtt/CMakeLists.txt               | 82 +++++++++++++++++--
 pico_w/wifi/mqtt/{mqtt_client => }/README     | 34 ++++++++
 pico_w/wifi/mqtt/certs/.gitignore             |  2 +
 pico_w/wifi/mqtt/certs/makecerts.sh           | 43 ++++++++++
 pico_w/wifi/mqtt/certs/pub.sh                 |  9 ++
 pico_w/wifi/mqtt/certs/sub.sh                 |  9 ++
 pico_w/wifi/mqtt/lwipopts.h                   | 30 +++++++
 pico_w/wifi/mqtt/mbedtls_config.h             |  6 ++
 .../wifi/mqtt/{mqtt_client => }/mqtt_client.c | 48 +++++++++--
 pico_w/wifi/mqtt/mqtt_client/CMakeLists.txt   | 49 -----------
 pico_w/wifi/mqtt/mqtt_client/lwipopts.h       | 12 ---
 12 files changed, 251 insertions(+), 75 deletions(-)
 rename pico_w/wifi/mqtt/{mqtt_client => }/README (51%)
 create mode 100644 pico_w/wifi/mqtt/certs/.gitignore
 create mode 100755 pico_w/wifi/mqtt/certs/makecerts.sh
 create mode 100755 pico_w/wifi/mqtt/certs/pub.sh
 create mode 100755 pico_w/wifi/mqtt/certs/sub.sh
 create mode 100644 pico_w/wifi/mqtt/lwipopts.h
 create mode 100644 pico_w/wifi/mqtt/mbedtls_config.h
 rename pico_w/wifi/mqtt/{mqtt_client => }/mqtt_client.c (81%)
 delete mode 100644 pico_w/wifi/mqtt/mqtt_client/CMakeLists.txt
 delete mode 100644 pico_w/wifi/mqtt/mqtt_client/lwipopts.h

diff --git a/pico_w/wifi/lwipopts_examples_common.h b/pico_w/wifi/lwipopts_examples_common.h
index 217cb1357..3cc083c64 100644
--- a/pico_w/wifi/lwipopts_examples_common.h
+++ b/pico_w/wifi/lwipopts_examples_common.h
@@ -20,7 +20,9 @@
 #define MEM_LIBC_MALLOC             0
 #endif
 #define MEM_ALIGNMENT               4
+#ifndef MEM_SIZE
 #define MEM_SIZE                    4000
+#endif
 #define MEMP_NUM_TCP_SEG            32
 #define MEMP_NUM_ARP_QUEUE          10
 #define PBUF_POOL_SIZE              24
diff --git a/pico_w/wifi/mqtt/CMakeLists.txt b/pico_w/wifi/mqtt/CMakeLists.txt
index 2f018792b..c371d5fe6 100644
--- a/pico_w/wifi/mqtt/CMakeLists.txt
+++ b/pico_w/wifi/mqtt/CMakeLists.txt
@@ -1,8 +1,78 @@
-cmake_minimum_required(VERSION 3.12)
+# Define the host name of the MQTT server in an environment variable or pass it to cmake,
+# e.g. cmake -DMQTT_SERVER=myserver ..
 
-project(test_mqtt C CXX ASM)
-set(CMAKE_C_STANDARD 11)
-set(CMAKE_CXX_STANDARD 17)
+if (DEFINED ENV{MQTT_SERVER} AND (NOT MQTT_SERVER))
+    set(MQTT_SERVER $ENV{MQTT_SERVER})
+    message("Using MQTT_SERVER from environment ('${MQTT_SERVER}')")
+endif()
+if (NOT MQTT_SERVER)
+    return()
+endif()
+# Define the name of an MQTT broker/server to enable this example
+set(MQTT_SERVER "${MQTT_SERVER}" CACHE INTERNAL "MQTT server for examples")
 
-add_subdirectory(mqtt_client)
-pico_sdk_init()
+if (DEFINED ENV{MQTT_USERNAME} AND (NOT MQTT_USERNAME))
+    set(MQTT_USERNAME $ENV{MQTT_USERNAME})
+    message("Using MQTT_USERNAME from environment ('${MQTT_USERNAME}')")
+endif()
+set(MQTT_USERNAME "${MQTT_USERNAME}" CACHE INTERNAL "MQTT user name for examples")
+if (DEFINED ENV{MQTT_PASSWORD} AND (NOT MQTT_PASSWORD))
+    set(MQTT_PASSWORD $ENV{MQTT_PASSWORD})
+    message("Using MQTT_PASSWORD from environment")
+endif()
+set(MQTT_PASSWORD "${MQTT_PASSWORD}" CACHE INTERNAL "MQTT password for examples")
+
+# Set path to the certificate include file
+if (NOT MQTT_CERT_PATH)
+    set(MQTT_CERT_PATH ${CMAKE_CURRENT_LIST_DIR}/certs/${MQTT_SERVER})
+endif()
+
+# Set the name of the certificate include file
+if (NOT MQTT_CERT_INC)
+    set(MQTT_CERT_INC mqtt_client.inc)
+endif()
+
+set(TARGET_NAME mqtt_client)
+add_executable(${TARGET_NAME}
+    mqtt_client.c
+    )
+target_link_libraries(${TARGET_NAME}
+    pico_stdlib
+    hardware_adc
+    pico_cyw43_arch_lwip_threadsafe_background
+    pico_lwip_mqtt
+    pico_mbedtls
+    pico_lwip_mbedtls
+    )
+target_include_directories(${TARGET_NAME} PRIVATE
+    ${CMAKE_CURRENT_LIST_DIR}
+    ${CMAKE_CURRENT_LIST_DIR}/.. # for our common lwipopts or any other standard includes, if required
+    )
+target_compile_definitions(${TARGET_NAME} PRIVATE
+    WIFI_SSID=\"${WIFI_SSID}\"
+    WIFI_PASSWORD=\"${WIFI_PASSWORD}\"
+    MQTT_SERVER=\"${MQTT_SERVER}\"
+    )
+if (EXISTS "${MQTT_CERT_PATH}/${MQTT_CERT_INC}")
+    target_compile_definitions(${TARGET_NAME} PRIVATE
+        MQTT_CERT_INC=\"${MQTT_CERT_INC}\" # contains the tls certificates for MQTT_SERVER needed by the client
+        ALTCP_MBEDTLS_AUTHMODE=MBEDTLS_SSL_VERIFY_REQUIRED
+        )
+    target_include_directories(${TARGET_NAME} PRIVATE
+        ${MQTT_CERT_PATH}
+        )
+endif()
+if (MQTT_USERNAME AND MQTT_PASSWORD)
+    target_compile_definitions(${TARGET_NAME} PRIVATE
+        MQTT_USERNAME=\"${MQTT_USERNAME}\"
+        MQTT_PASSWORD=\"${MQTT_PASSWORD}\"
+    )
+endif()
+pico_add_extra_outputs(${TARGET_NAME})
+
+# Ignore warnings from lwip code
+set_source_files_properties(
+    ${PICO_LWIP_PATH}/src/apps/altcp_tls/altcp_tls_mbedtls.c
+    PROPERTIES
+    COMPILE_OPTIONS "-Wno-unused-result"
+    )
\ No newline at end of file
diff --git a/pico_w/wifi/mqtt/mqtt_client/README b/pico_w/wifi/mqtt/README
similarity index 51%
rename from pico_w/wifi/mqtt/mqtt_client/README
rename to pico_w/wifi/mqtt/README
index b4c124f2f..e1889bb61 100644
--- a/pico_w/wifi/mqtt/mqtt_client/README
+++ b/pico_w/wifi/mqtt/README
@@ -58,3 +58,37 @@ export MQTT_PASSWORD=pass
 ```
 
 Be aware that these details are sent in plain text unless you use TLS.
+
+## Using TLS
+
+To use TLS and client server authentication you need some keys and certificates for the client and server.
+The `certs/makecerts.sh` script demonstrates a way to make these.
+It creates a folder named after `MQTT_SERVER` containing all the required files.
+From these files it generates a header file `mqtt_client.inc` included by the code.
+Your server will have to be configured to use TLS and the port 8883 rather than the non-TLS port 1883.
+
+```
+listener 1883 127.0.0.1
+
+listener 8883 0.0.0.0
+allow_anonymous true
+cafile /etc/mosquitto/ca_certificates/ca.crt
+certfile /etc/mosquitto/certs/server.crt
+keyfile /etc/mosquitto/certs/server.key
+require_certificate true
+```
+
+To connect to your server with the mosquitto tools in linux you will have to pass extra parameters.
+
+```
+mosquitto_pub -h $MQTT_SERVER --cafile $MQTT_SERVER/ca.crt --key $MQTT_SERVER/client.key --cert $MQTT_SERVER/client.crt -t /led -m on
+mosquitto_sub -h $MQTT_SERVER --cafile $MQTT_SERVER/ca.crt --key $MQTT_SERVER/client.key --cert $MQTT_SERVER/client.crt -t "/temperature"
+```
+
+There are some shell scripts in the certs folder to reduce the amount of typing assuming `MQTT_SERVER` is defined.
+
+```
+cd certs
+./pub.sh /led on
+./sub.sh /temperature
+```
diff --git a/pico_w/wifi/mqtt/certs/.gitignore b/pico_w/wifi/mqtt/certs/.gitignore
new file mode 100644
index 000000000..d92150c7c
--- /dev/null
+++ b/pico_w/wifi/mqtt/certs/.gitignore
@@ -0,0 +1,2 @@
+*/
+
diff --git a/pico_w/wifi/mqtt/certs/makecerts.sh b/pico_w/wifi/mqtt/certs/makecerts.sh
new file mode 100755
index 000000000..c95b9c8f8
--- /dev/null
+++ b/pico_w/wifi/mqtt/certs/makecerts.sh
@@ -0,0 +1,43 @@
+#!/usr/bin/bash
+
+if [ "${PWD##*/}" != "certs" ]; then
+    echo Run this in the certs folder
+    exit 1
+fi
+if [ -z "$MQTT_SERVER" ]; then
+    echo Define MQTT_SERVER
+    exit 1
+fi
+SERVER_NAME=$MQTT_SERVER
+
+if [ -d "$SERVER_NAME" ]; then
+    echo Run \"rm -fr $SERVER_NAME\" to regenerate these keys
+    exit 1
+fi
+mkdir $SERVER_NAME
+echo Generating keys in $PWD/$SERVER_NAME
+
+openssl genrsa -out $SERVER_NAME/ca.key 2048
+openssl req -new -x509 -days 99999 -key $SERVER_NAME/ca.key -out $SERVER_NAME/ca.crt -subj "/C=UK/ST=Cambridgeshire/L=Cambridge/O=Raspberry Pi Ltd/OU=Software/CN=rpiroot"
+
+openssl genrsa -out $SERVER_NAME/server.key 2048
+openssl req -new -out $SERVER_NAME/server.csr -key $SERVER_NAME/server.key -subj "/C=UK/ST=Cambridgeshire/L=Cambridge/O=Raspberry Pi Ltd/OU=Software/CN=$SERVER_NAME"
+openssl x509 -req -in $SERVER_NAME/server.csr -CA $SERVER_NAME/ca.crt -CAkey $SERVER_NAME/ca.key -CAcreateserial -out $SERVER_NAME/server.crt -days 9999
+
+openssl genrsa -out $SERVER_NAME/client.key 2048
+openssl req -new -out $SERVER_NAME/client.csr -key $SERVER_NAME/client.key -subj "/C=UK/ST=Cambridgeshire/L=Cambridge/O=Raspberry Pi Ltd/OU=Software/CN=$SERVER_NAME"
+openssl x509 -req -in $SERVER_NAME/client.csr -CA $SERVER_NAME/ca.crt -CAkey $SERVER_NAME/ca.key -CAcreateserial -out $SERVER_NAME/client.crt -days 999
+
+echo -n \#define TLS_ROOT_CERT \" > $SERVER_NAME/mqtt_client.inc
+cat $SERVER_NAME/ca.crt | awk '{printf "%s\\n\\\n", $0}' >> $SERVER_NAME/mqtt_client.inc
+echo "\"" >> $SERVER_NAME/mqtt_client.inc
+echo >> $SERVER_NAME/mqtt_client.inc
+
+echo -n \#define TLS_CLIENT_KEY \" >> $SERVER_NAME/mqtt_client.inc
+cat $SERVER_NAME/client.key | awk '{printf "%s\\n\\\n", $0}' >> $SERVER_NAME/mqtt_client.inc
+echo "\"" >> $SERVER_NAME/mqtt_client.inc
+echo >> $SERVER_NAME/mqtt_client.inc
+
+echo -n \#define TLS_CLIENT_CERT \" >> $SERVER_NAME/mqtt_client.inc
+cat $SERVER_NAME/client.crt | awk '{printf "%s\\n\\\n", $0}' >> $SERVER_NAME/mqtt_client.inc
+echo "\"" >> $SERVER_NAME/mqtt_client.inc
diff --git a/pico_w/wifi/mqtt/certs/pub.sh b/pico_w/wifi/mqtt/certs/pub.sh
new file mode 100755
index 000000000..38b9b7d37
--- /dev/null
+++ b/pico_w/wifi/mqtt/certs/pub.sh
@@ -0,0 +1,9 @@
+#/usr/bin/bash
+
+if [ -z "$MQTT_SERVER" ]; then
+    echo Define MQTT_SERVER
+    exit 1
+fi
+
+mosquitto_pub -h $MQTT_SERVER --cafile $MQTT_SERVER/ca.crt --key $MQTT_SERVER/client.key --cert $MQTT_SERVER/client.crt -t "$1" -m "$2"
+
diff --git a/pico_w/wifi/mqtt/certs/sub.sh b/pico_w/wifi/mqtt/certs/sub.sh
new file mode 100755
index 000000000..54b9376ad
--- /dev/null
+++ b/pico_w/wifi/mqtt/certs/sub.sh
@@ -0,0 +1,9 @@
+#/usr/bin/bash
+
+if [ -z "$MQTT_SERVER" ]; then
+    echo Define MQTT_SERVER
+    exit 1
+fi
+
+mosquitto_sub -h $MQTT_SERVER --cafile $MQTT_SERVER/ca.crt --key $MQTT_SERVER/client.key --cert $MQTT_SERVER/client.crt -t "$1"
+
diff --git a/pico_w/wifi/mqtt/lwipopts.h b/pico_w/wifi/mqtt/lwipopts.h
new file mode 100644
index 000000000..09c11cb8b
--- /dev/null
+++ b/pico_w/wifi/mqtt/lwipopts.h
@@ -0,0 +1,30 @@
+#ifndef _LWIPOPTS_H
+#define _LWIPOPTS_H
+
+// Need more memory for TLS
+#ifdef MQTT_CERT_INC
+#define MEM_SIZE 8000
+#endif
+
+// Generally you would define your own explicit list of lwIP options
+// (see https://www.nongnu.org/lwip/2_1_x/group__lwip__opts.html)
+//
+// This example uses a common include to avoid repetition
+#include "lwipopts_examples_common.h"
+
+#define MEMP_NUM_SYS_TIMEOUT        (LWIP_NUM_SYS_TIMEOUT_INTERNAL+1)
+
+#ifdef MQTT_CERT_INC
+#define LWIP_ALTCP               1
+#define LWIP_ALTCP_TLS           1
+#define LWIP_ALTCP_TLS_MBEDTLS   1
+#ifndef NDEBUG
+#define ALTCP_MBEDTLS_DEBUG  LWIP_DBG_ON
+#endif
+/* TCP WND must be at least 16 kb to match TLS record size
+   or you will get a warning "altcp_tls: TCP_WND is smaller than the RX decrypion buffer, connection RX might stall!" */
+#undef TCP_WND
+#define TCP_WND  16384
+#endif // MQTT_CERT_INC
+
+#endif
diff --git a/pico_w/wifi/mqtt/mbedtls_config.h b/pico_w/wifi/mqtt/mbedtls_config.h
new file mode 100644
index 000000000..f182c5661
--- /dev/null
+++ b/pico_w/wifi/mqtt/mbedtls_config.h
@@ -0,0 +1,6 @@
+#ifndef MBEDTLS_CONFIG_TLS_CLIENT_H
+#define MBEDTLS_CONFIG_TLS_CLIENT_H
+
+#include "mbedtls_config_examples_common.h"
+
+#endif
\ No newline at end of file
diff --git a/pico_w/wifi/mqtt/mqtt_client/mqtt_client.c b/pico_w/wifi/mqtt/mqtt_client.c
similarity index 81%
rename from pico_w/wifi/mqtt/mqtt_client/mqtt_client.c
rename to pico_w/wifi/mqtt/mqtt_client.c
index 43acd700c..e7b437dc2 100644
--- a/pico_w/wifi/mqtt/mqtt_client/mqtt_client.c
+++ b/pico_w/wifi/mqtt/mqtt_client.c
@@ -14,7 +14,9 @@
 #include "hardware/irq.h"
 #include "hardware/adc.h"
 #include "lwip/apps/mqtt.h"
+#include "lwip/apps/mqtt_priv.h" // needed to set hostname
 #include "lwip/dns.h"
+#include "lwip/altcp_tls.h"
 
 // Temperature
 #ifndef TEMPERATURE_UNITS
@@ -25,9 +27,9 @@
 #error Need to define MQTT_SERVER
 #endif
 
-// MQTT parameters
-#ifndef MQTT_PORT
-#define MQTT_PORT 1883
+// This file includes your client certificate for client server authentication
+#ifdef MQTT_CERT_INC
+#include MQTT_CERT_INC
 #endif
 
 typedef struct {
@@ -129,6 +131,14 @@ static void mqtt_connection_cb(mqtt_client_t *client, void *arg, mqtt_connection
 }
 
 static void start_client(MQTT_CLIENT_DATA_T *state) {
+#if LWIP_ALTCP && LWIP_ALTCP_TLS
+    const int port = MQTT_TLS_PORT;
+    printf("Using TLS\n");
+#else
+    const int port = MQTT_PORT;
+    printf("Warning: Not using TLS\n");
+#endif
+
     state->mqtt_client_inst = mqtt_client_new();
     if (!state->mqtt_client_inst) {
         panic("MQTT client instance creation error");
@@ -137,9 +147,13 @@ static void start_client(MQTT_CLIENT_DATA_T *state) {
     printf("Connecting to mqtt server at %s\n", ipaddr_ntoa(&state->mqtt_server_address));
 
     cyw43_arch_lwip_begin();
-    if (mqtt_client_connect(state->mqtt_client_inst, &state->mqtt_server_address, MQTT_PORT, mqtt_connection_cb, state, &state->mqtt_client_info) != ERR_OK) {
+    if (mqtt_client_connect(state->mqtt_client_inst, &state->mqtt_server_address, port, mqtt_connection_cb, state, &state->mqtt_client_info) != ERR_OK) {
         panic("MQTT broker connection error");
     }
+#if LWIP_ALTCP && LWIP_ALTCP_TLS
+    // This is important for MBEDTLS_SSL_SERVER_NAME_INDICATION
+    mbedtls_ssl_set_hostname(altcp_tls_context(state->mqtt_client_inst->conn), MQTT_SERVER);
+#endif
     mqtt_set_inpub_callback(state->mqtt_client_inst, mqtt_incoming_publish_cb, mqtt_incoming_data_cb, state);
     cyw43_arch_lwip_end();
 }
@@ -157,6 +171,7 @@ static void dns_found(const char *hostname, const ip_addr_t *ipaddr, void *arg)
 
 int main(void) {
     stdio_init_all();
+    printf("mqtt client starting\n");
 
     adc_init();
     adc_set_temp_sensor_enabled(true);
@@ -164,6 +179,10 @@ int main(void) {
 
     static MQTT_CLIENT_DATA_T state;
 
+    if (cyw43_arch_init()) {
+        panic("Failed to inizialize CYW43");
+    }
+
     // Use board unique id for the client id
     static char client_id_buf[PICO_UNIQUE_BOARD_ID_SIZE_BYTES * 2 + 1];
     pico_get_unique_board_id_string(client_id_buf, sizeof(client_id_buf));
@@ -176,10 +195,23 @@ int main(void) {
     state.mqtt_client_info.client_user = NULL;
     state.mqtt_client_info.client_pass = NULL;
 #endif
-
-    if (cyw43_arch_init()) {
-        panic("Failed to inizialize CYW43");
-    }
+#if LWIP_ALTCP && LWIP_ALTCP_TLS
+    // TLS enabled
+#ifdef MQTT_CERT_INC
+    static const uint8_t ca_cert[] = TLS_ROOT_CERT;
+    static const uint8_t client_key[] = TLS_CLIENT_KEY;
+    static const uint8_t client_cert[] = TLS_CLIENT_CERT;
+    // This confirms the indentity of the server and the client
+    state.mqtt_client_info.tls_config = altcp_tls_create_config_client_2wayauth(ca_cert, sizeof(ca_cert),
+            client_key, sizeof(client_key), NULL, 0, client_cert, sizeof(client_cert));
+#if ALTCP_MBEDTLS_AUTHMODE != MBEDTLS_SSL_VERIFY_REQUIRED
+    WARN_printf("Warning: tls without verification is insecure\n");
+#endif
+#else
+    state->client_info.tls_config = altcp_tls_create_config_client(NULL, 0);
+    WARN_printf("Warning: tls without a certificate is insecure\n");
+#endif
+#endif
 
     cyw43_arch_enable_sta_mode();
     if (cyw43_arch_wifi_connect_timeout_ms(WIFI_SSID, WIFI_PASSWORD, CYW43_AUTH_WPA2_AES_PSK, 30000)) {
diff --git a/pico_w/wifi/mqtt/mqtt_client/CMakeLists.txt b/pico_w/wifi/mqtt/mqtt_client/CMakeLists.txt
deleted file mode 100644
index c2ea20927..000000000
--- a/pico_w/wifi/mqtt/mqtt_client/CMakeLists.txt
+++ /dev/null
@@ -1,49 +0,0 @@
-# Define the host name of the MQTT server in an environment variable or pass it to cmake,
-# e.g. cmake -DMQTT_SERVER=myserver ..
-
-if (DEFINED ENV{MQTT_SERVER} AND (NOT MQTT_SERVER))
-    set(MQTT_SERVER $ENV{MQTT_SERVER})
-    message("Using MQTT_SERVER from environment ('${MQTT_SERVER}')")
-endif()
-if (NOT MQTT_SERVER)
-    return()
-endif()
-if (DEFINED ENV{MQTT_USERNAME} AND (NOT MQTT_USERNAME))
-    set(MQTT_USERNAME $ENV{MQTT_USERNAME})
-    message("Using MQTT_USERNAME from environment ('${MQTT_USERNAME}')")
-endif()
-if (DEFINED ENV{MQTT_PASSWORD} AND (NOT MQTT_PASSWORD))
-    set(MQTT_PASSWORD $ENV{MQTT_PASSWORD})
-    message("Using MQTT_PASSWORD from environment")
-endif()
-
-# Define the name of an MQTT broker/server to enable this example
-set(MQTT_SERVER "${MQTT_SERVER}" CACHE INTERNAL "MQTT server for examples")
-
-set(TARGET_NAME mqtt_client)
-
-add_executable(${TARGET_NAME}
-    mqtt_client.c
-)
-target_link_libraries(${TARGET_NAME}
-    pico_stdlib
-    hardware_adc
-    pico_cyw43_arch_lwip_threadsafe_background
-    pico_lwip_mqtt
-)
-target_include_directories(${TARGET_NAME} PRIVATE
-    ${CMAKE_CURRENT_LIST_DIR}
-    ${CMAKE_CURRENT_LIST_DIR}/../.. # for our common lwipopts or any other standard includes, if required
-)
-target_compile_definitions(${TARGET_NAME} PRIVATE
-    WIFI_SSID=\"${WIFI_SSID}\"
-    WIFI_PASSWORD=\"${WIFI_PASSWORD}\"
-    MQTT_SERVER=\"${MQTT_SERVER}\"
-)
-if (MQTT_USERNAME AND MQTT_PASSWORD)
-    target_compile_definitions(${TARGET_NAME} PRIVATE
-        MQTT_USERNAME=\"${MQTT_USERNAME}\"
-        MQTT_PASSWORD=\"${MQTT_PASSWORD}\"
-    )
-endif()
-pico_add_extra_outputs(${TARGET_NAME})
diff --git a/pico_w/wifi/mqtt/mqtt_client/lwipopts.h b/pico_w/wifi/mqtt/mqtt_client/lwipopts.h
deleted file mode 100644
index e4817116f..000000000
--- a/pico_w/wifi/mqtt/mqtt_client/lwipopts.h
+++ /dev/null
@@ -1,12 +0,0 @@
-#ifndef _LWIPOPTS_H
-#define _LWIPOPTS_H
-
-// Generally you would define your own explicit list of lwIP options
-// (see https://www.nongnu.org/lwip/2_1_x/group__lwip__opts.html)
-//
-// This example uses a common include to avoid repetition
-#include "lwipopts_examples_common.h"
-
-#define MEMP_NUM_SYS_TIMEOUT        (LWIP_NUM_SYS_TIMEOUT_INTERNAL+1)
-
-#endif

From 53f52b247e9f512556fd6c9d6d0f49b4d28695d6 Mon Sep 17 00:00:00 2001
From: Peter Harper <peter.harper@raspberrypi.com>
Date: Thu, 30 Jan 2025 12:03:52 +0000
Subject: [PATCH 08/11] Add some more topics

print, just print the message to stdout
ping, publish uptime to pong
exit, quit the client
---
 pico_w/wifi/mqtt/mqtt_client.c | 92 ++++++++++++++++++++++++++++------
 1 file changed, 76 insertions(+), 16 deletions(-)

diff --git a/pico_w/wifi/mqtt/mqtt_client.c b/pico_w/wifi/mqtt/mqtt_client.c
index e7b437dc2..230126e69 100644
--- a/pico_w/wifi/mqtt/mqtt_client.c
+++ b/pico_w/wifi/mqtt/mqtt_client.c
@@ -39,8 +39,23 @@ typedef struct {
     char topic[100];
     uint32_t len;
     ip_addr_t mqtt_server_address;
+    bool connect_done;
+    int subscribe_count;
+    bool stop_client;
 } MQTT_CLIENT_DATA_T;
 
+#ifndef DEBUG_printf
+#ifndef NDEBUG
+#define DEBUG_printf printf
+#else
+#define DEBUG_printf(...)
+#endif
+#endif
+
+#ifndef INFO_printf
+#define INFO_printf printf
+#endif
+
 /* References for this implementation:
  * raspberry-pi-pico-c-sdk.pdf, Section '4.1.1. hardware_adc'
  * pico-examples/adc/adc_console/adc_console.c */
@@ -83,31 +98,69 @@ static void publish_temperature(MQTT_CLIENT_DATA_T *state) {
         // Publish temperature on /temperature topic
         char temp_str[16];
         snprintf(temp_str, sizeof(temp_str), "%.2f", temperature);
-        printf("Publishing %s to %s\n", temp_str, temperature_key);
+        INFO_printf("Publishing %s to %s\n", temp_str, temperature_key);
         mqtt_publish(state->mqtt_client_inst, temperature_key, temp_str, strlen(temp_str), 0, 0, NULL, NULL);
     }
 }
 
+static void sub_request_cb(void *arg, err_t err) {
+    MQTT_CLIENT_DATA_T* state = (MQTT_CLIENT_DATA_T*)arg;
+    if (err != 0) {
+        panic("subscribe request failed %d", err);
+    }
+    state->subscribe_count++;
+}
+
+static void unsub_request_cb(void *arg, err_t err) {
+    MQTT_CLIENT_DATA_T* state = (MQTT_CLIENT_DATA_T*)arg;
+    if (err != 0) {
+        panic("unsubscribe request failed %d", err);
+    }
+    state->subscribe_count--;
+    assert(state->subscribe_count >= 0);
+
+    // Stop if requested
+    if (state->subscribe_count <= 0 && state->stop_client) {
+        mqtt_disconnect(state->mqtt_client_inst);
+    }
+}
+
+static void sub_unsub_topics(MQTT_CLIENT_DATA_T* state, bool sub) {
+    mqtt_request_cb_t cb = sub ? sub_request_cb : unsub_request_cb;
+    mqtt_sub_unsub(state->mqtt_client_inst, "/led", 0, cb, state, sub);
+    mqtt_sub_unsub(state->mqtt_client_inst, "/print", 0, cb, state, sub);
+    mqtt_sub_unsub(state->mqtt_client_inst, "/ping", 0, cb, state, sub);
+    mqtt_sub_unsub(state->mqtt_client_inst, "/exit", 0, cb, state, sub);
+}
+
 static void mqtt_incoming_data_cb(void *arg, const u8_t *data, u16_t len, u8_t flags) {
     MQTT_CLIENT_DATA_T* state = (MQTT_CLIENT_DATA_T*)arg;
     strncpy(state->data, (const char *)data, len);
     state->len = len;
     state->data[len] = '\0';
 
-    printf("Topic: %s, Message: %s\n", state->topic, state->data);
-
+    DEBUG_printf("Topic: %s, Message: %s\n", state->topic, state->data);
     if (strcmp(state->topic, "/led") == 0)
     {
         if (lwip_stricmp((const char *)state->data, "On") == 0)
             control_led(state, true);
         else if  (lwip_stricmp((const char *)state->data, "Off") == 0)
             control_led(state, false);
+    } else if (strcmp(state->topic, "/print") == 0) {
+        INFO_printf("%.*s\n", len, data);
+    } else if (strcmp(state->topic, "/ping") == 0) {
+        char buf[11];
+        snprintf(buf, sizeof(buf), "%u", to_ms_since_boot(get_absolute_time()) / 1000);
+        mqtt_publish(state->mqtt_client_inst, "/pong", buf, strlen(buf), 0, 0, NULL, NULL);
+    } else if (strcmp(state->topic, "/exit") == 0) {
+        state->stop_client = true; // stop the client when ALL subscriptions are stopped
+        sub_unsub_topics(state, false); // unsubscribe
     }
 }
 
 static void mqtt_incoming_publish_cb(void *arg, const char *topic, u32_t tot_len) {
-    MQTT_CLIENT_DATA_T* mqtt_client = (MQTT_CLIENT_DATA_T*)arg;
-    strncpy(mqtt_client->topic, topic, sizeof(mqtt_client->topic));
+    MQTT_CLIENT_DATA_T* state = (MQTT_CLIENT_DATA_T*)arg;
+    strncpy(state->topic, topic, sizeof(state->topic));
 }
 
 static void temperature_worker_fn(async_context_t *context, async_at_time_worker_t *worker) {
@@ -118,14 +171,20 @@ static void temperature_worker_fn(async_context_t *context, async_at_time_worker
 static async_at_time_worker_t temperature_worker = { .do_work = temperature_worker_fn };
 
 static void mqtt_connection_cb(mqtt_client_t *client, void *arg, mqtt_connection_status_t status) {
+    MQTT_CLIENT_DATA_T* state = (MQTT_CLIENT_DATA_T*)arg;
     if (status == MQTT_CONNECT_ACCEPTED) {
-        mqtt_sub_unsub(client, "/led", 0, NULL, arg, 1);
-        printf("Connected to the /led topic successfully\n");
+        state->connect_done = true;
+        sub_unsub_topics(state, true); // subscribe;
 
         // Publish temperature every 10 sec if it's changed
-        temperature_worker.user_data = arg;
+        temperature_worker.user_data = state;
         async_context_add_at_time_worker_in_ms(cyw43_arch_async_context(), &temperature_worker, 0);
-    } else {
+    } else if (status == MQTT_CONNECT_DISCONNECTED) {
+        if (!state->connect_done) {
+            panic("Failed to connect to mqtt server");
+        }
+    }
+    else {
         panic("Unexpected status");
     }
 }
@@ -133,18 +192,18 @@ static void mqtt_connection_cb(mqtt_client_t *client, void *arg, mqtt_connection
 static void start_client(MQTT_CLIENT_DATA_T *state) {
 #if LWIP_ALTCP && LWIP_ALTCP_TLS
     const int port = MQTT_TLS_PORT;
-    printf("Using TLS\n");
+    INFO_printf("Using TLS\n");
 #else
     const int port = MQTT_PORT;
-    printf("Warning: Not using TLS\n");
+    INFO_printf("Warning: Not using TLS\n");
 #endif
 
     state->mqtt_client_inst = mqtt_client_new();
     if (!state->mqtt_client_inst) {
         panic("MQTT client instance creation error");
     }
-    printf("IP address of this device %s\n", ipaddr_ntoa(&(netif_list->ip_addr)));
-    printf("Connecting to mqtt server at %s\n", ipaddr_ntoa(&state->mqtt_server_address));
+    INFO_printf("IP address of this device %s\n", ipaddr_ntoa(&(netif_list->ip_addr)));
+    INFO_printf("Connecting to mqtt server at %s\n", ipaddr_ntoa(&state->mqtt_server_address));
 
     cyw43_arch_lwip_begin();
     if (mqtt_client_connect(state->mqtt_client_inst, &state->mqtt_server_address, port, mqtt_connection_cb, state, &state->mqtt_client_info) != ERR_OK) {
@@ -171,7 +230,7 @@ static void dns_found(const char *hostname, const ip_addr_t *ipaddr, void *arg)
 
 int main(void) {
     stdio_init_all();
-    printf("mqtt client starting\n");
+    INFO_printf("mqtt client starting\n");
 
     adc_init();
     adc_set_temp_sensor_enabled(true);
@@ -217,7 +276,7 @@ int main(void) {
     if (cyw43_arch_wifi_connect_timeout_ms(WIFI_SSID, WIFI_PASSWORD, CYW43_AUTH_WPA2_AES_PSK, 30000)) {
         panic("Failed to connect");
     }
-    printf("\nConnected to Wifi\n");
+    INFO_printf("\nConnected to Wifi\n");
 
     // We are not in a callback so locking is needed when calling lwip
     // Make a DNS request for the MQTT server IP address
@@ -232,10 +291,11 @@ int main(void) {
         panic("dns request failed");
     }
 
-    while (true) {
+    while (!state.connect_done || mqtt_client_is_connected(state.mqtt_client_inst)) {
         cyw43_arch_poll();
         cyw43_arch_wait_for_work_until(make_timeout_time_ms(10000));
     }
 
+    INFO_printf("mqtt client exiting\n");
     return 0;
 }

From 103a49601ddf5c9ec93f744866405e892295ae6e Mon Sep 17 00:00:00 2001
From: Peter Harper <peter.harper@raspberrypi.com>
Date: Thu, 30 Jan 2025 13:13:56 +0000
Subject: [PATCH 09/11] Add will topic /online

Add some defines for some magic numbers
---
 pico_w/wifi/mqtt/lwipopts.h    |  3 ++
 pico_w/wifi/mqtt/mqtt_client.c | 56 ++++++++++++++++++++++++++++------
 2 files changed, 50 insertions(+), 9 deletions(-)

diff --git a/pico_w/wifi/mqtt/lwipopts.h b/pico_w/wifi/mqtt/lwipopts.h
index 09c11cb8b..c309d5cb3 100644
--- a/pico_w/wifi/mqtt/lwipopts.h
+++ b/pico_w/wifi/mqtt/lwipopts.h
@@ -27,4 +27,7 @@
 #define TCP_WND  16384
 #endif // MQTT_CERT_INC
 
+// This defaults to 4
+#define MQTT_REQ_MAX_IN_FLIGHT 5
+
 #endif
diff --git a/pico_w/wifi/mqtt/mqtt_client.c b/pico_w/wifi/mqtt/mqtt_client.c
index 230126e69..ddd673358 100644
--- a/pico_w/wifi/mqtt/mqtt_client.c
+++ b/pico_w/wifi/mqtt/mqtt_client.c
@@ -56,6 +56,29 @@ typedef struct {
 #define INFO_printf printf
 #endif
 
+#ifndef ERROR_printf
+#define ERROR_printf printf
+#endif
+
+// how often to measure our temperature
+#define TEMP_WORKER_TIME_S 10
+
+// keep alive in seconds
+#define MQTT_KEEP_ALIVE_S 60
+
+// qos passed to mqtt_subscribe
+// At most once (QoS 0)
+// At least once (QoS 1)
+// Exactly once (QoS 2)
+#define MQTT_SUBSCRIBE_QOS 1
+#define MQTT_PUBLISH_QOS 1
+#define MQTT_PUBLISH_RETAIN 0
+
+// topic used for last will and testament
+#define MQTT_WILL_TOPIC "/online"
+#define MQTT_WILL_MSG "0"
+#define MQTT_WILL_QOS 1
+
 /* References for this implementation:
  * raspberry-pi-pico-c-sdk.pdf, Section '4.1.1. hardware_adc'
  * pico-examples/adc/adc_console/adc_console.c */
@@ -76,6 +99,12 @@ static float read_onboard_temperature(const char unit) {
     return -1.0f;
 }
 
+static void pub_request_cb(__unused void *arg, err_t err) {
+    if (err != 0) {
+        ERROR_printf("pub_request_cb failed %d", err);
+    }
+}
+
 static void control_led(MQTT_CLIENT_DATA_T *state, bool on) {
     // Publish state on /state topic and on/off led board
     const char* message = on ? "On" : "Off";
@@ -86,7 +115,7 @@ static void control_led(MQTT_CLIENT_DATA_T *state, bool on) {
 
     char state_topic[128];
     snprintf(state_topic, sizeof(state_topic), "%s/state", state->topic);
-    mqtt_publish(state->mqtt_client_inst, state_topic, message, strlen(message), 0, 0, NULL, NULL);
+    mqtt_publish(state->mqtt_client_inst, state_topic, message, strlen(message), MQTT_PUBLISH_QOS, MQTT_PUBLISH_RETAIN, pub_request_cb, state);
 }
 
 static void publish_temperature(MQTT_CLIENT_DATA_T *state) {
@@ -99,7 +128,7 @@ static void publish_temperature(MQTT_CLIENT_DATA_T *state) {
         char temp_str[16];
         snprintf(temp_str, sizeof(temp_str), "%.2f", temperature);
         INFO_printf("Publishing %s to %s\n", temp_str, temperature_key);
-        mqtt_publish(state->mqtt_client_inst, temperature_key, temp_str, strlen(temp_str), 0, 0, NULL, NULL);
+        mqtt_publish(state->mqtt_client_inst, temperature_key, temp_str, strlen(temp_str), MQTT_PUBLISH_QOS, MQTT_PUBLISH_RETAIN, pub_request_cb, state);
     }
 }
 
@@ -127,10 +156,10 @@ static void unsub_request_cb(void *arg, err_t err) {
 
 static void sub_unsub_topics(MQTT_CLIENT_DATA_T* state, bool sub) {
     mqtt_request_cb_t cb = sub ? sub_request_cb : unsub_request_cb;
-    mqtt_sub_unsub(state->mqtt_client_inst, "/led", 0, cb, state, sub);
-    mqtt_sub_unsub(state->mqtt_client_inst, "/print", 0, cb, state, sub);
-    mqtt_sub_unsub(state->mqtt_client_inst, "/ping", 0, cb, state, sub);
-    mqtt_sub_unsub(state->mqtt_client_inst, "/exit", 0, cb, state, sub);
+    mqtt_sub_unsub(state->mqtt_client_inst, "/led", MQTT_SUBSCRIBE_QOS, cb, state, sub);
+    mqtt_sub_unsub(state->mqtt_client_inst, "/print", MQTT_SUBSCRIBE_QOS, cb, state, sub);
+    mqtt_sub_unsub(state->mqtt_client_inst, "/ping", MQTT_SUBSCRIBE_QOS, cb, state, sub);
+    mqtt_sub_unsub(state->mqtt_client_inst, "/exit", MQTT_SUBSCRIBE_QOS, cb, state, sub);
 }
 
 static void mqtt_incoming_data_cb(void *arg, const u8_t *data, u16_t len, u8_t flags) {
@@ -151,7 +180,7 @@ static void mqtt_incoming_data_cb(void *arg, const u8_t *data, u16_t len, u8_t f
     } else if (strcmp(state->topic, "/ping") == 0) {
         char buf[11];
         snprintf(buf, sizeof(buf), "%u", to_ms_since_boot(get_absolute_time()) / 1000);
-        mqtt_publish(state->mqtt_client_inst, "/pong", buf, strlen(buf), 0, 0, NULL, NULL);
+        mqtt_publish(state->mqtt_client_inst, "/pong", buf, strlen(buf), MQTT_PUBLISH_QOS, MQTT_PUBLISH_RETAIN, pub_request_cb, state);
     } else if (strcmp(state->topic, "/exit") == 0) {
         state->stop_client = true; // stop the client when ALL subscriptions are stopped
         sub_unsub_topics(state, false); // unsubscribe
@@ -166,7 +195,7 @@ static void mqtt_incoming_publish_cb(void *arg, const char *topic, u32_t tot_len
 static void temperature_worker_fn(async_context_t *context, async_at_time_worker_t *worker) {
     MQTT_CLIENT_DATA_T* state = (MQTT_CLIENT_DATA_T*)worker->user_data;
     publish_temperature(state);
-    async_context_add_at_time_worker_in_ms(context, worker, 10000); // repeat in 10s
+    async_context_add_at_time_worker_in_ms(context, worker, TEMP_WORKER_TIME_S * 1000);
 }
 static async_at_time_worker_t temperature_worker = { .do_work = temperature_worker_fn };
 
@@ -176,6 +205,11 @@ static void mqtt_connection_cb(mqtt_client_t *client, void *arg, mqtt_connection
         state->connect_done = true;
         sub_unsub_topics(state, true); // subscribe;
 
+        // indicate online
+        if (state->mqtt_client_info.will_topic) {
+            mqtt_publish(state->mqtt_client_inst, state->mqtt_client_info.will_topic, "1", 1, MQTT_WILL_QOS, true, pub_request_cb, state);
+        }
+
         // Publish temperature every 10 sec if it's changed
         temperature_worker.user_data = state;
         async_context_add_at_time_worker_in_ms(cyw43_arch_async_context(), &temperature_worker, 0);
@@ -246,7 +280,7 @@ int main(void) {
     static char client_id_buf[PICO_UNIQUE_BOARD_ID_SIZE_BYTES * 2 + 1];
     pico_get_unique_board_id_string(client_id_buf, sizeof(client_id_buf));
     state.mqtt_client_info.client_id = client_id_buf;
-    state.mqtt_client_info.keep_alive = 60; // Keep alive in sec
+    state.mqtt_client_info.keep_alive = MQTT_KEEP_ALIVE_S; // Keep alive in sec
 #if defined(MQTT_USERNAME) && defined(MQTT_PASSWORD)
     state.mqtt_client_info.client_user = MQTT_USERNAME;
     state.mqtt_client_info.client_pass = MQTT_PASSWORD;
@@ -254,6 +288,10 @@ int main(void) {
     state.mqtt_client_info.client_user = NULL;
     state.mqtt_client_info.client_pass = NULL;
 #endif
+    state.mqtt_client_info.will_topic = MQTT_WILL_TOPIC;
+    state.mqtt_client_info.will_msg = MQTT_WILL_MSG;
+    state.mqtt_client_info.will_qos = MQTT_WILL_QOS;
+    state.mqtt_client_info.will_retain = true;
 #if LWIP_ALTCP && LWIP_ALTCP_TLS
     // TLS enabled
 #ifdef MQTT_CERT_INC

From 3593551361dfad53d5d96703858928d8308c3e1e Mon Sep 17 00:00:00 2001
From: Peter Harper <peter.harper@raspberrypi.com>
Date: Thu, 30 Jan 2025 14:19:17 +0000
Subject: [PATCH 10/11] Unique topic names per device

Disabled by default with MQTT_UNIQUE_TOPIC
---
 pico_w/wifi/mqtt/mqtt_client.c | 79 +++++++++++++++++++++++++---------
 1 file changed, 59 insertions(+), 20 deletions(-)

diff --git a/pico_w/wifi/mqtt/mqtt_client.c b/pico_w/wifi/mqtt/mqtt_client.c
index ddd673358..fdcd238a0 100644
--- a/pico_w/wifi/mqtt/mqtt_client.c
+++ b/pico_w/wifi/mqtt/mqtt_client.c
@@ -32,11 +32,15 @@
 #include MQTT_CERT_INC
 #endif
 
+#ifndef MQTT_TOPIC_LEN
+#define MQTT_TOPIC_LEN 100
+#endif
+
 typedef struct {
     mqtt_client_t* mqtt_client_inst;
     struct mqtt_connect_client_info_t mqtt_client_info;
     char data[MQTT_OUTPUT_RINGBUF_SIZE];
-    char topic[100];
+    char topic[MQTT_TOPIC_LEN];
     uint32_t len;
     ip_addr_t mqtt_server_address;
     bool connect_done;
@@ -79,6 +83,15 @@ typedef struct {
 #define MQTT_WILL_MSG "0"
 #define MQTT_WILL_QOS 1
 
+#ifndef MQTT_DEVICE_NAME
+#define MQTT_DEVICE_NAME "pico"
+#endif
+
+// Set to 1 to add the client name to topics, to support multiple devices using the same server
+#ifndef MQTT_UNIQUE_TOPIC
+#define MQTT_UNIQUE_TOPIC 0
+#endif
+
 /* References for this implementation:
  * raspberry-pi-pico-c-sdk.pdf, Section '4.1.1. hardware_adc'
  * pico-examples/adc/adc_console/adc_console.c */
@@ -105,6 +118,16 @@ static void pub_request_cb(__unused void *arg, err_t err) {
     }
 }
 
+static const char *full_topic(MQTT_CLIENT_DATA_T *state, const char *name) {
+#if MQTT_UNIQUE_TOPIC
+    static char full_topic[MQTT_TOPIC_LEN];
+    snprintf(full_topic, sizeof(full_topic), "/%s%s", state->mqtt_client_info.client_id, name);
+    return full_topic;
+#else
+    return name;
+#endif
+}
+
 static void control_led(MQTT_CLIENT_DATA_T *state, bool on) {
     // Publish state on /state topic and on/off led board
     const char* message = on ? "On" : "Off";
@@ -113,14 +136,12 @@ static void control_led(MQTT_CLIENT_DATA_T *state, bool on) {
     else
         cyw43_arch_gpio_put(CYW43_WL_GPIO_LED_PIN, 0);
 
-    char state_topic[128];
-    snprintf(state_topic, sizeof(state_topic), "%s/state", state->topic);
-    mqtt_publish(state->mqtt_client_inst, state_topic, message, strlen(message), MQTT_PUBLISH_QOS, MQTT_PUBLISH_RETAIN, pub_request_cb, state);
+    mqtt_publish(state->mqtt_client_inst, full_topic(state, "/led/state"), message, strlen(message), MQTT_PUBLISH_QOS, MQTT_PUBLISH_RETAIN, pub_request_cb, state);
 }
 
 static void publish_temperature(MQTT_CLIENT_DATA_T *state) {
     static float old_temperature;
-    const char temperature_key[] = "/temperature";
+    const char *temperature_key = full_topic(state, "/temperature");
     float temperature = read_onboard_temperature(TEMPERATURE_UNITS);
     if (temperature != old_temperature) {
         old_temperature = temperature;
@@ -156,32 +177,37 @@ static void unsub_request_cb(void *arg, err_t err) {
 
 static void sub_unsub_topics(MQTT_CLIENT_DATA_T* state, bool sub) {
     mqtt_request_cb_t cb = sub ? sub_request_cb : unsub_request_cb;
-    mqtt_sub_unsub(state->mqtt_client_inst, "/led", MQTT_SUBSCRIBE_QOS, cb, state, sub);
-    mqtt_sub_unsub(state->mqtt_client_inst, "/print", MQTT_SUBSCRIBE_QOS, cb, state, sub);
-    mqtt_sub_unsub(state->mqtt_client_inst, "/ping", MQTT_SUBSCRIBE_QOS, cb, state, sub);
-    mqtt_sub_unsub(state->mqtt_client_inst, "/exit", MQTT_SUBSCRIBE_QOS, cb, state, sub);
+    mqtt_sub_unsub(state->mqtt_client_inst, full_topic(state, "/led"), MQTT_SUBSCRIBE_QOS, cb, state, sub);
+    mqtt_sub_unsub(state->mqtt_client_inst, full_topic(state, "/print"), MQTT_SUBSCRIBE_QOS, cb, state, sub);
+    mqtt_sub_unsub(state->mqtt_client_inst, full_topic(state, "/ping"), MQTT_SUBSCRIBE_QOS, cb, state, sub);
+    mqtt_sub_unsub(state->mqtt_client_inst, full_topic(state, "/exit"), MQTT_SUBSCRIBE_QOS, cb, state, sub);
 }
 
 static void mqtt_incoming_data_cb(void *arg, const u8_t *data, u16_t len, u8_t flags) {
     MQTT_CLIENT_DATA_T* state = (MQTT_CLIENT_DATA_T*)arg;
+#if MQTT_UNIQUE_TOPIC
+    const char *basic_topic = state->topic + strlen(state->mqtt_client_info.client_id) + 1;
+#else
+    const char *basic_topic = state->topic;
+#endif
     strncpy(state->data, (const char *)data, len);
     state->len = len;
     state->data[len] = '\0';
 
     DEBUG_printf("Topic: %s, Message: %s\n", state->topic, state->data);
-    if (strcmp(state->topic, "/led") == 0)
+    if (strcmp(basic_topic, "/led") == 0)
     {
-        if (lwip_stricmp((const char *)state->data, "On") == 0)
+        if (lwip_stricmp((const char *)state->data, "On") == 0 || strcmp((const char *)state->data, "1") == 0)
             control_led(state, true);
-        else if  (lwip_stricmp((const char *)state->data, "Off") == 0)
+        else if (lwip_stricmp((const char *)state->data, "Off") == 0 || strcmp((const char *)state->data, "0") == 0)
             control_led(state, false);
-    } else if (strcmp(state->topic, "/print") == 0) {
+    } else if (strcmp(basic_topic, "/print") == 0) {
         INFO_printf("%.*s\n", len, data);
-    } else if (strcmp(state->topic, "/ping") == 0) {
+    } else if (strcmp(basic_topic, "/ping") == 0) {
         char buf[11];
         snprintf(buf, sizeof(buf), "%u", to_ms_since_boot(get_absolute_time()) / 1000);
-        mqtt_publish(state->mqtt_client_inst, "/pong", buf, strlen(buf), MQTT_PUBLISH_QOS, MQTT_PUBLISH_RETAIN, pub_request_cb, state);
-    } else if (strcmp(state->topic, "/exit") == 0) {
+        mqtt_publish(state->mqtt_client_inst, full_topic(state, "/pong"), buf, strlen(buf), MQTT_PUBLISH_QOS, MQTT_PUBLISH_RETAIN, pub_request_cb, state);
+    } else if (strcmp(basic_topic, "/exit") == 0) {
         state->stop_client = true; // stop the client when ALL subscriptions are stopped
         sub_unsub_topics(state, false); // unsubscribe
     }
@@ -276,9 +302,20 @@ int main(void) {
         panic("Failed to inizialize CYW43");
     }
 
-    // Use board unique id for the client id
-    static char client_id_buf[PICO_UNIQUE_BOARD_ID_SIZE_BYTES * 2 + 1];
-    pico_get_unique_board_id_string(client_id_buf, sizeof(client_id_buf));
+    // Use board unique id
+    char unique_id_buf[5];
+    pico_get_unique_board_id_string(unique_id_buf, sizeof(unique_id_buf));
+    for(int i=0; i < sizeof(unique_id_buf) - 1; i++) {
+        unique_id_buf[i] = tolower(unique_id_buf[i]);
+    }
+
+    // Generate a unique name, e.g. pico1234
+    char client_id_buf[sizeof(MQTT_DEVICE_NAME) + sizeof(unique_id_buf) - 1];
+    memcpy(&client_id_buf[0], MQTT_DEVICE_NAME, sizeof(MQTT_DEVICE_NAME) - 1);
+    memcpy(&client_id_buf[sizeof(MQTT_DEVICE_NAME) - 1], unique_id_buf, sizeof(unique_id_buf) - 1);
+    client_id_buf[sizeof(client_id_buf) - 1] = 0;
+    INFO_printf("Device name %s\n", client_id_buf);
+
     state.mqtt_client_info.client_id = client_id_buf;
     state.mqtt_client_info.keep_alive = MQTT_KEEP_ALIVE_S; // Keep alive in sec
 #if defined(MQTT_USERNAME) && defined(MQTT_PASSWORD)
@@ -288,7 +325,9 @@ int main(void) {
     state.mqtt_client_info.client_user = NULL;
     state.mqtt_client_info.client_pass = NULL;
 #endif
-    state.mqtt_client_info.will_topic = MQTT_WILL_TOPIC;
+    static char will_topic[MQTT_TOPIC_LEN];
+    strncpy(will_topic, full_topic(&state, MQTT_WILL_TOPIC), sizeof(will_topic));
+    state.mqtt_client_info.will_topic = will_topic;
     state.mqtt_client_info.will_msg = MQTT_WILL_MSG;
     state.mqtt_client_info.will_qos = MQTT_WILL_QOS;
     state.mqtt_client_info.will_retain = true;

From 39cf06ecd0d0871177a3a41a2795b22e75e6fbf7 Mon Sep 17 00:00:00 2001
From: Peter Harper <peter.harper@raspberrypi.com>
Date: Wed, 5 Feb 2025 13:15:59 +0000
Subject: [PATCH 11/11] Some MQTT updates

Change /pong to /uptime
Display a message if MQTT_SERVER is not defined
Put picow_ in the name like the other examples
Add details to the readme!
---
 README.md                       | 1 +
 pico_w/wifi/mqtt/CMakeLists.txt | 3 ++-
 pico_w/wifi/mqtt/mqtt_client.c  | 2 +-
 3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index ab13be68e..01a98ff3e 100644
--- a/README.md
+++ b/README.md
@@ -191,6 +191,7 @@ App|Description
 [picow_httpd](pico_w/wifi/httpd) | Runs a LWIP HTTP server test app
 [picow_http_client](pico_w/wifi/http_client) | Demonstrates how to make http and https requests
 [picow_http_client_verify](pico_w/wifi/http_client) | Demonstrates how to make a https request with server authentication
+[picow_mqtt_client](pico_w/wifi/mqtt) | Demonstrates how to implement an MQTT client application
 
 #### FreeRTOS examples
 
diff --git a/pico_w/wifi/mqtt/CMakeLists.txt b/pico_w/wifi/mqtt/CMakeLists.txt
index c371d5fe6..23dfa250f 100644
--- a/pico_w/wifi/mqtt/CMakeLists.txt
+++ b/pico_w/wifi/mqtt/CMakeLists.txt
@@ -6,6 +6,7 @@ if (DEFINED ENV{MQTT_SERVER} AND (NOT MQTT_SERVER))
     message("Using MQTT_SERVER from environment ('${MQTT_SERVER}')")
 endif()
 if (NOT MQTT_SERVER)
+    message("Skipping MQTT example as MQTT_SERVER is not defined")
     return()
 endif()
 # Define the name of an MQTT broker/server to enable this example
@@ -32,7 +33,7 @@ if (NOT MQTT_CERT_INC)
     set(MQTT_CERT_INC mqtt_client.inc)
 endif()
 
-set(TARGET_NAME mqtt_client)
+set(TARGET_NAME picow_mqtt_client)
 add_executable(${TARGET_NAME}
     mqtt_client.c
     )
diff --git a/pico_w/wifi/mqtt/mqtt_client.c b/pico_w/wifi/mqtt/mqtt_client.c
index fdcd238a0..b70d6885d 100644
--- a/pico_w/wifi/mqtt/mqtt_client.c
+++ b/pico_w/wifi/mqtt/mqtt_client.c
@@ -206,7 +206,7 @@ static void mqtt_incoming_data_cb(void *arg, const u8_t *data, u16_t len, u8_t f
     } else if (strcmp(basic_topic, "/ping") == 0) {
         char buf[11];
         snprintf(buf, sizeof(buf), "%u", to_ms_since_boot(get_absolute_time()) / 1000);
-        mqtt_publish(state->mqtt_client_inst, full_topic(state, "/pong"), buf, strlen(buf), MQTT_PUBLISH_QOS, MQTT_PUBLISH_RETAIN, pub_request_cb, state);
+        mqtt_publish(state->mqtt_client_inst, full_topic(state, "/uptime"), buf, strlen(buf), MQTT_PUBLISH_QOS, MQTT_PUBLISH_RETAIN, pub_request_cb, state);
     } else if (strcmp(basic_topic, "/exit") == 0) {
         state->stop_client = true; // stop the client when ALL subscriptions are stopped
         sub_unsub_topics(state, false); // unsubscribe