Fix OTA disconnect issue #253 and adjust examples to changes. Add new connection state example

Author: MathewHDYT

.github/workflows/espidf-compile-v4.4.yml

@@ -54,3 +54,9 @@ jobs:
         esp_idf_version: v4.4
         target: esp32
         path: 'examples/0018-espressif_esp32_provision_device'
+    - name: Build process connection state example on v4.4
+      uses: espressif/esp-idf-ci-action@v1
+      with:
+        esp_idf_version: v4.4
+        target: esp32
+        path: 'examples/0020-espressif_esp32_connection_state'

.github/workflows/espidf-compile-v5.1.yml

@@ -54,3 +54,9 @@ jobs:
         esp_idf_version: v5.1
         target: esp32
         path: 'examples/0018-espressif_esp32_provision_device'
+    - name: Build process connection state example on v5.1
+      uses: espressif/esp-idf-ci-action@v1
+      with:
+        esp_idf_version: v5.1
+        target: esp32
+        path: 'examples/0020-espressif_esp32_connection_state'

README.md

@@ -631,7 +631,7 @@ class Custom_MQTT_Client : public IMQTT_Client {
         return MQTT_Connection_Error::NONE;
     }
 
-    void set_connect_cycle_callback(Callback<void(MQTT_Connection_State, MQTT_Connection_Error)>::function callback) override {
+    void subscribe_connection_state_changed_callback(Callback<void, MQTT_Connection_State, MQTT_Connection_Error>::function callback) override;
         // Nothing to do
     }
 

examples/0014-espressif_esp32_send_data/main/0014-espressif_esp32_send_data.cpp

@@ -156,6 +156,10 @@ extern "C" void app_main() {
             tb.connect(THINGSBOARD_SERVER, TOKEN, THINGSBOARD_PORT);
         }
 
+        while (!tb.connected()) {
+            vTaskDelay(1000 / portTICK_PERIOD_MS);
+        }
+
         tb.Send_Telemetry_Data(TEMPERATURE_KEY, esp_random());
         tb.Send_Telemetry_Data(HUMIDITY_KEY, esp_random());
 

examples/0015-espressif_esp32_process_OTA_MQTT/main/0015-espressif_esp32_process_OTA_MQTT.cpp

@@ -273,6 +273,10 @@ extern "C" void app_main() {
             tb.connect(THINGSBOARD_SERVER, TOKEN, THINGSBOARD_PORT);
         }
 
+        while (!tb.connected()) {
+            vTaskDelay(1000 / portTICK_PERIOD_MS);
+        }
+
         if (!currentFWSent) {
             currentFWSent = ota.Firmware_Send_Info(CURRENT_FIRMWARE_TITLE, CURRENT_FIRMWARE_VERSION);
         }

examples/0016-espressif_esp32_rpc/main/0016-espressif_esp32_rpc.cpp

@@ -214,6 +214,10 @@ extern "C" void app_main(void) {
             tb.connect(THINGSBOARD_SERVER, TOKEN, THINGSBOARD_PORT);
         }
 
+        while (!tb.connected()) {
+            vTaskDelay(1000 / portTICK_PERIOD_MS);
+        }
+
         if (!subscribed) {
             const std::array<RPC_Callback, MAX_RPC_SUBSCRIPTIONS> callbacks = {
               // Requires additional memory in the JsonDocument for the JsonDocument that will be copied into the response

examples/0017-espressif_esp32_process_shared_attribute_update/main/0017-espressif_esp32_process_shared_attribute_update.cpp

@@ -191,6 +191,10 @@ extern "C" void app_main(void) {
             tb.connect(THINGSBOARD_SERVER, TOKEN, THINGSBOARD_PORT);
         }
 
+        while (!tb.connected()) {
+            vTaskDelay(1000 / portTICK_PERIOD_MS);
+        }
+
         if (!subscribed) {
             // Shared attributes we want to request from the server
             constexpr std::array<const char*, MAX_ATTRIBUTES> SUBSCRIBED_SHARED_ATTRIBUTES = {FW_CHKS_KEY, FW_CHKS_ALGO_KEY, FW_SIZE_KEY, FW_TAG_KEY, FW_TITLE_KEY, FW_VER_KEY};

examples/0018-espressif_esp32_provision_device/main/0018-espressif_esp32_provision_device.cpp

@@ -256,6 +256,11 @@ void provision_device(void *pvParameters) {
         tb.disconnect();
     }
 
+    // Wait for the provisioning device to disconnect
+    while (tb.connected()) {
+        vTaskDelay(1000 / portTICK_PERIOD_MS);
+    }
+
     // Connect to the ThingsBoard server, as the provisioned client
     tb.connect(THINGSBOARD_SERVER, credentials.username.c_str(), THINGSBOARD_PORT, credentials.client_id.c_str(), credentials.password.c_str());
 

examples/0020-espressif_esp32_connection_state/CMakeLists.txt

@@ -0,0 +1,9 @@
+# For more information about build system see
+# https://docs.espressif.com/projects/esp-idf/en/latest/api-guides/build-system.html
+cmake_minimum_required(VERSION 3.5)
+
+# Set project version
+set(PROJECT_VER "0.1.1")
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+project(ESP32_CONN_STATE)

examples/0020-espressif_esp32_connection_state/README.md

@@ -0,0 +1,19 @@
+# Detecting and reacting to connection state
+
+## Devices
+| Supported Devices |
+|-------------------|
+|  ESP32            |
+
+## Framework
+
+Espressif IDF
+
+## ThingsBoard API
+-
+
+## Feature
+Allows detecting and react to changes in the connection state. Especially useful when using the `Espressif_MQTT_Client`, because both the `disconnect` and `connect` method are non-blocking.
+This means that directly calling `connect` and then attempting to send data to ThingsBoard will cause the calls to fail, because the connection has not been established yet.
+
+To fix this we can either read the current state of the device, so whether it is still connecting or already connected. Alternatively, we can subscribe a callback that will automatically inform once the connection state changes, so we are also informed if the device is now connected.