esp8266-temp-monitor.cc

#include <ESP8266WiFi.h>
#include <WEMOS_SHT3X.h>
#include "Adafruit_MQTT.h"
#include "Adafruit_MQTT_Client.h"

/************************* WiFi Access Point *********************************/

#define WLAN_SSID       "my-ssid"
#define WLAN_PASS       "my-wifi-password"

/************************* Adafruit.io Setup *********************************/

#define AIO_SERVER      "io.adafruit.com"
#define AIO_SERVERPORT  1883
#define AIO_USERNAME    "my-aio-account"
#define AIO_KEY         "my-aio-key"

/************ Global State (you don't need to change this!) ******************/

// Create an ESP8266 WiFiClient class to connect to the MQTT server.
WiFiClient client;

// Store the MQTT server, username, and password in flash memory.
// This is required for using the Adafruit MQTT library.
const char *MQTT_SERVER    = AIO_SERVER;
const char *MQTT_USERNAME  = AIO_USERNAME;
const char *MQTT_PASSWORD  = AIO_KEY;

// Setup the MQTT client class by passing in the WiFi client and MQTT server and login details.
#define DEVICE_ID "0"  // I couldn't figure out how to embed the device ID
                       // using this library, which requires strings to be in flash
Adafruit_MQTT_Client mqtt(&client, MQTT_SERVER, AIO_SERVERPORT, MQTT_USERNAME, MQTT_PASSWORD);
Adafruit_MQTT_Publish device = Adafruit_MQTT_Publish(&mqtt, AIO_USERNAME "/f/device");
Adafruit_MQTT_Publish temperature = Adafruit_MQTT_Publish(&mqtt, AIO_USERNAME "/f/temperature-" DEVICE_ID);
Adafruit_MQTT_Publish humidity = Adafruit_MQTT_Publish(&mqtt, AIO_USERNAME "/f/humidity-" DEVICE_ID);

/*************************** 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();

static String device_name;

void setup() {
  Serial.begin(115200);
  delay(10);

  device_name = String("esp8266-") + ESP.getChipId();

  // Connect to WiFi access point.
  Serial.println(); Serial.println();
  Serial.print("Connecting to ");
  Serial.println(WLAN_SSID);

  WiFi.begin(WLAN_SSID, WLAN_PASS);
  Serial.println("wifi connecting...");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.print("connected");
  Serial.println();
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
}

// 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("Connecting to MQTT... ");

  while ((ret = mqtt.connect()) != 0) { // connect will return 0 for connected
    Serial.println(mqtt.connectErrorString(ret));
    mqtt.disconnect();
    delay(5000);  // wait 5 seconds
  }
  Serial.println("MQTT Connected!");
}

static bool first_loop = true;
char last_now[64] = "--";

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();
  if (first_loop) {
    first_loop = false;
    device.publish((device_name + "online").c_str());
  }

  if (sht30.get() == 0) {
    temperature.publish(sht30.fTemp);
    humidity.publish(sht30.humidity);
  }

  // ping the server to keep the mqtt connection alive
  if (!mqtt.ping()) {
    mqtt.disconnect();
  }

  //  delay(1000 * 60 * 10);
  delay(30 * 1000);

  if (WiFi.status() != WL_CONNECTED) {
    ESP.reset();
  }
}