io.run now returns status, doesn't hang

This walks back my more agreesive solution in the interest of backwards compatibility.

It provides a new example that protects against dropped network connections.

Author: sellensr

examples/adafruitio_02_pubsub_protected/adafruitio_02_pubsub_protected.ino

@@ -0,0 +1,117 @@
+// Adafruit IO Publish/Subscribe Example with Protection
+//
+// Adafruit invests time and resources providing this open source code.
+// Please support Adafruit and open source hardware by purchasing
+// products from Adafruit!
+//
+// Written by Todd Treece for Adafruit Industries
+// Copyright (c) 2016 Adafruit Industries
+// Licensed under the MIT license.
+//
+// All text above must be included in any redistribution.
+
+/************************** Configuration ***********************************/
+// Comment out if you do not maintain an ssid.h file for your personal credentials.
+// Then add your own credentials in the config.h tab. 
+#include "ssid.h"   
+
+// edit the config.h tab and enter your Adafruit IO credentials
+// and any additional configuration needed for WiFi, cellular,
+// or ethernet clients.
+#include "config.h"
+
+/************************ Example Starts Here *******************************/
+// This pub/sub example tests the status and reconnects if the network goes down.
+
+// this int will hold the current count for our sketch
+int count = 0;
+
+// set up the 'counter' feed
+AdafruitIO_Feed *counter = io.feed("counter");
+// https://io.adafruit.com/api/docs/mqtt.html#username-errors
+//AdafruitIO_Feed *throttles = io.feed("throttle");
+//AdafruitIO_Feed *errors = io.feed("errors");
+
+void setup() {
+
+  // start the serial connection
+  Serial.begin(115200);
+
+  // wait for serial monitor to open
+  while(! Serial);
+
+  setupIO();
+}
+
+void setupIO() {
+  Serial.print("Connecting to Adafruit IO");
+
+  // connect to io.adafruit.com -- must be called before any other io calls!
+  // calling io.status() first will make the subsequent connection attempt fail.
+  io.connect();
+  counter->onMessage(handleMessage);
+
+  // wait for a connection
+  unsigned long started = millis();
+  while(io.status() < AIO_CONNECTED) {
+    if(millis() - started > 30000){ 
+      started = millis();
+      io.connect();  // try again if you run out of patience
+    }
+    Serial.print(".");
+    delay(500);
+  }
+
+  // we are connected
+  Serial.println();
+  Serial.println(io.statusText());
+  counter->get();   // https://io.adafruit.com/api/docs/mqtt.html#using-the-get-topic
+}
+
+void handleMessage(AdafruitIO_Data *data) {
+  Serial.print("\nreceived <- ");
+  Serial.println(data->value());
+}
+
+void loop() {
+
+  // io.run(); is required for all sketches.
+  // it should always be present at the top of your loop
+  // function. it keeps the client connected to
+  // io.adafruit.com, and processes any incoming data.
+  if(millis()%60000 > 30000){ 
+    WiFi.disconnect();                          // Wifi will die in the top half of every minute
+    delay(300);                                 // wait a while for the disaster to show...
+  }
+  Serial.print("\n\nTop of Loop!\nio.status: ");Serial.print(io.status()); 
+  Serial.print(": ");                           Serial.print(io.statusText());    Serial.print("\n"); 
+  Serial.print("io.networkStatus: ");           Serial.print(io.networkStatus()); Serial.print("\n"); 
+  Serial.print("io.mqttStatus: ");              Serial.print(io.mqttStatus());    Serial.print("\n"); 
+  Serial.print("WiFi.status: ");                Serial.print(WiFi.status());      Serial.print("\n"); 
+
+  // Here's where we check the network and start over if it has lost connection
+  if(io.status() < AIO_NET_CONNECTED){         
+    Serial.print("Not Net Connected to IO!!! Reconnect!!!\n\n");
+    count++;
+    setupIO(); //Start IO all over again
+  }
+
+  Serial.print("Calling io.run()...");        // io.run() will hang if network disconnected 2019-11-16
+  io.run();                                   // process messages and keep connection alive
+  Serial.print("Done\n");
+  
+  // save count to the 'counter' feed on Adafruit IO
+  Serial.print("sending -> ");
+  Serial.print(count);
+  if(counter->save(count)) Serial.print(" sent!");
+  else Serial.print(" failed to send!");
+
+  // Adafruit IO is rate limited for publishing, so a delay is required in
+  // between feed->save events. In this example, we will wait three seconds
+  // (1000 milliseconds == 1 second) during each loop.
+  // Adding the if statement allows you to generate a burst of faster saves
+  // to generate some throttling events and see how the code responds.
+  if(millis() < 90000 || millis() > 120000) delay(3000);
+  else delay(5000);
+
+}

examples/adafruitio_02_pubsub_protected/config.h

@@ -0,0 +1,67 @@
+/************************ Adafruit IO Config *******************************/
+
+// visit io.adafruit.com if you need to create an account,
+// or if you need your Adafruit IO key.
+// Uncomment these lines and add your own credentials if needed
+//#define IO_USERNAME   "your_username"
+//#define IO_KEY        "your_key"
+
+/******************************* WIFI **************************************/
+
+// the AdafruitIO_WiFi client will work with the following boards:
+//   - HUZZAH ESP8266 Breakout -> https://www.adafruit.com/products/2471
+//   - Feather HUZZAH ESP8266 -> https://www.adafruit.com/products/2821
+//   - Feather HUZZAH ESP32 -> https://www.adafruit.com/product/3405
+//   - Feather M0 WiFi -> https://www.adafruit.com/products/3010
+//   - Feather WICED -> https://www.adafruit.com/products/3056
+//   - Adafruit PyPortal -> https://www.adafruit.com/product/4116
+//   - Adafruit Metro M4 Express AirLift Lite -> https://www.adafruit.com/product/4000
+//   - Adafruit AirLift Breakout -> https://www.adafruit.com/product/4201
+//   - Adafruit AirLift Shield -> https://www.adafruit.com/product/4285
+//   - Adafruit AirLift FeatherWing -> https://www.adafruit.com/product/4264
+
+//#define WIFI_SSID   "your_ssid"
+//#define WIFI_PASS   "your_pass"
+
+// uncomment the following line if you are using airlift
+// #define USE_AIRLIFT
+
+// uncomment the following line if you are using winc1500
+#define USE_WINC1500
+
+// comment out the following lines if you are using fona or ethernet
+#include "AdafruitIO_WiFi.h"
+
+#if defined(USE_AIRLIFT) || defined(ADAFRUIT_METRO_M4_AIRLIFT_LITE)
+  // Configure the pins used for the ESP32 connection
+  #if !defined(SPIWIFI_SS) // if the wifi definition isnt in the board variant
+    // Don't change the names of these #define's! they match the variant ones
+    #define SPIWIFI SPI
+    #define SPIWIFI_SS 10  // Chip select pin
+    #define NINA_ACK 9    // a.k.a BUSY or READY pin
+    #define NINA_RESETN 6 // Reset pin
+    #define NINA_GPIO0 -1 // Not connected
+  #endif
+  AdafruitIO_WiFi io(IO_USERNAME, IO_KEY, WIFI_SSID, WIFI_PASS, SPIWIFI_SS, NINA_ACK, NINA_RESETN, NINA_GPIO0, &SPIWIFI);
+#else
+  AdafruitIO_WiFi io(IO_USERNAME, IO_KEY, WIFI_SSID, WIFI_PASS);
+#endif
+/******************************* FONA **************************************/
+
+// the AdafruitIO_FONA client will work with the following boards:
+//   - Feather 32u4 FONA -> https://www.adafruit.com/product/3027
+
+// uncomment the following two lines for 32u4 FONA,
+// and comment out the AdafruitIO_WiFi client in the WIFI section
+// #include "AdafruitIO_FONA.h"
+// AdafruitIO_FONA io(IO_USERNAME, IO_KEY);
+
+/**************************** ETHERNET ************************************/
+
+// the AdafruitIO_Ethernet client will work with the following boards:
+//   - Ethernet FeatherWing -> https://www.adafruit.com/products/3201
+
+// uncomment the following two lines for ethernet,
+// and comment out the AdafruitIO_WiFi client in the WIFI section
+// #include "AdafruitIO_Ethernet.h"
+// AdafruitIO_Ethernet io(IO_USERNAME, IO_KEY);

src/AdafruitIO.cpp

@@ -165,9 +165,18 @@ const __FlashStringHelper* AdafruitIO::statusText()
   }
 }
 
-void AdafruitIO::run(uint16_t busywait_ms)
+aio_status_t AdafruitIO::run(uint16_t busywait_ms)
 {
+  aio_status_t net_status = networkStatus();
+  // If we aren't connected, return network status -- fail quickly
+  // Previous version would just hang on a network error
+  if(net_status != AIO_NET_CONNECTED) {
+    _status = net_status;
+    return _status;
+  }
+  
   // loop until we have a connection
+  // mqttStatus() will try to reconnect before returning
   while(mqttStatus() != AIO_CONNECTED){}
 
   if(busywait_ms > 0)
@@ -241,7 +250,7 @@ aio_status_t AdafruitIO::mqttStatus()
 
   if(_mqtt->connected())
     return AIO_CONNECTED;
-
+  
   switch(_mqtt->connect(_username, _key)) {
     case 0:
       return AIO_CONNECTED;

src/AdafruitIO.h

@@ -45,7 +45,7 @@ class AdafruitIO {
     virtual ~AdafruitIO();
 
     void connect();
-    void run(uint16_t busywait_ms = 0);
+    aio_status_t run(uint16_t busywait_ms = 0);
 
     AdafruitIO_Feed* feed(const char *name);
     AdafruitIO_Feed* feed(const char *name, const char *owner);