Added arbitrary buffer example

examples/mqtt_arbitrary_buffer/mqtt_arbitrary_buffer.ino

@@ -0,0 +1,155 @@
+/***************************************************
+  Adafruit MQTT Library ESP8266 Example
+
+  Must use ESP8266 Arduino from:
+    https://github.com/esp8266/Arduino
+
+  Works great with Adafruit's Huzzah ESP board & Feather
+  ----> https://www.adafruit.com/product/2471
+  ----> https://www.adafruit.com/products/2821
+
+  Adafruit invests time and resources providing this open source code,
+  please support Adafruit and open-source hardware by purchasing
+  products from Adafruit!
+
+  Written by Tony DiCola for Adafruit Industries.
+  MIT license, all text above must be included in any redistribution
+ ****************************************************/
+#include <ESP8266WiFi.h>
+#include "Adafruit_MQTT.h"
+#include "Adafruit_MQTT_Client.h"
+
+/************************* WiFi Access Point *********************************/
+
+#define WLAN_SSID       "...your SSID..."
+#define WLAN_PASS       "...your password..."
+
+/************************* Adafruit.io Setup *********************************/
+
+#define AIO_SERVER      "io.adafruit.com"
+#define AIO_SERVERPORT  1883                   // use 8883 for SSL
+#define AIO_USERNAME    "...your AIO username (see https://accounts.adafruit.com)..."
+#define AIO_KEY         "...your AIO key..."
+
+/************ Global State (you don't need to change this!) ******************/
+
+// Create an ESP8266 WiFiClient class to connect to the MQTT server.
+WiFiClient client;
+// or... use WiFiFlientSecure for SSL
+//WiFiClientSecure client;
+
+// Store the MQTT server, username, and password in flash memory.
+// This is required for using the Adafruit MQTT library.
+const char MQTT_SERVER[] PROGMEM    = AIO_SERVER;
+const char MQTT_USERNAME[] PROGMEM  = AIO_USERNAME;
+const char MQTT_PASSWORD[] PROGMEM  = AIO_KEY;
+
+// Setup the MQTT client class by passing in the WiFi client and MQTT server and login details.
+Adafruit_MQTT_Client mqtt(&client, MQTT_SERVER, AIO_SERVERPORT, MQTT_USERNAME, MQTT_PASSWORD);
+
+/****************************** Feeds ***************************************/
+
+// Setup a feed called 'photocell' for publishing.
+// Notice MQTT paths for AIO follow the form: <username>/feeds/<feedname>
+const char PHOTOCELL_FEED[] PROGMEM = AIO_USERNAME "/feeds/photocell";
+Adafruit_MQTT_Publish photocell = Adafruit_MQTT_Publish(&mqtt, PHOTOCELL_FEED);
+
+// Setup a feed called 'onoff' for subscribing to changes.
+const char ONOFF_FEED[] PROGMEM = AIO_USERNAME "/feeds/onoff";
+Adafruit_MQTT_Subscribe onoffbutton = Adafruit_MQTT_Subscribe(&mqtt, ONOFF_FEED);
+
+/*************************** Sketch Code ************************************/
+
+// Bug workaround for Arduino 1.6.6, it seems to need a function declaration
+// for some reason (only affects ESP8266, likely an arduino-builder bug).
+void MQTT_connect();
+
+void setup() {
+  Serial.begin(115200);
+  delay(10);
+
+  Serial.println(F("Adafruit MQTT demo"));
+
+  // Connect to WiFi access point.
+  Serial.println(); Serial.println();
+  Serial.print(F("Connecting to "));
+  Serial.println(WLAN_SSID);
+
+  WiFi.begin(WLAN_SSID, WLAN_PASS);
+  while (WiFi.status() != WL_CONNECTED) {
+    delay(500);
+    Serial.print(F("."));
+  }
+  Serial.println();
+
+  Serial.println(F("WiFi connected"));
+  Serial.println(F("IP address: ")); Serial.println(WiFi.localIP());
+
+  // Setup MQTT subscription for onoff feed.
+  mqtt.subscribe(&onoffbutton);
+}
+
+uint32_t x=0;
+
+void loop() {
+  // Ensure the connection to the MQTT server is alive (this will make the first
+  // connection and automatically reconnect when disconnected).  See the MQTT_connect
+  // function definition further below.
+  MQTT_connect();
+
+  // this is our 'wait for incoming subscription packets' busy subloop
+  // try to spend your time here
+
+  Adafruit_MQTT_Subscribe *subscription;
+  while ((subscription = mqtt.readSubscription(5000))) {
+    if (subscription == &onoffbutton) {
+      Serial.println(F("Got: "));
+      Serial.println((char *)onoffbutton.lastread);
+    }
+  }
+
+  // Now we can publish stuff!
+  Serial.print(F("\nSending photocell val "));
+  Serial.print(x);
+  Serial.print(F("..."));
+  if (! photocell.publish(x++)) {
+    Serial.println(F("Failed"));
+  } else {
+    Serial.println(F("OK!"));
+  }
+
+  // ping the server to keep the mqtt connection alive
+  // NOT required if you are publishing once every KEEPALIVE seconds
+  /*
+  if(! mqtt.ping()) {
+    mqtt.disconnect();
+  }
+  */
+}
+
+// Function to connect and reconnect as necessary to the MQTT server.
+// Should be called in the loop function and it will take care if connecting.
+void MQTT_connect() {
+  int8_t ret;
+
+  // Stop if already connected.
+  if (mqtt.connected()) {
+    return;
+  }
+
+  Serial.print(F("Connecting to MQTT... "));
+
+  uint8_t retries = 3;
+  while ((ret = mqtt.connect()) != 0) { // connect will return 0 for connected
+       Serial.println(mqtt.connectErrorString(ret));
+       Serial.println(F("Retrying MQTT connection in 5 seconds..."));
+       mqtt.disconnect();
+       delay(5000);  // wait 5 seconds
+       retries--;
+       if (retries == 0) {
+         // basically die and wait for WDT to reset me
+         while (1);
+       }
+  }
+  Serial.println(F("MQTT Connected!"));
+}