ESP8266 Community Forum

- Thu Jan 28, 2016 6:59 am #39868 ESP'ians ,
I have been messing around with a DHT script over from Adafruit's learn site where they use 2 ESP's (albeit Huzzah) to send DHT sensor information via one device and control a lamp via another device connected to their mqtt dashboard.
So I decided to use only one ESP device to do both by combining the 2 scripts as I decided it would be good to turn on/off the porch light too
My problem is it works as it should but! the DHT sampling delay time seems to give me a small window between updates to turn on or off the lamp .
Following is the code , if someone can spot the mistake I am making and help me correct it , would be appreciated .

Code: Select all/***************************************************
  Adafruit ESP8266 Sensor Module
 
  Must use ESP8266 Arduino from:
    https://github.com/esp8266/Arduino
  Works great with Adafruit's Huzzah ESP board:
  ----> https://www.adafruit.com/product/2471
  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
 ****************************************************/

// Libraries
#include <ESP8266WiFi.h>
#include "Adafruit_MQTT.h"
#include "Adafruit_MQTT_Client.h"
#include "DHT.h"

// DHT 11 sensor
#define DHTPIN 13
#define DHTTYPE DHT21  //AM2301

/************************* 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
#define AIO_USERNAME    "your ID"
#define AIO_KEY         "your key"

// DHT sensor
DHT dht(DHTPIN, DHTTYPE, 15);
// Lamp pin
const int lamp_pin = 2;

// Functions
void connect();

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

// Store the MQTT server, client ID, username, and password in flash memory.
const char MQTT_SERVER[] PROGMEM    = AIO_SERVER;

// Set a unique MQTT client ID using the AIO key + the date and time the sketch
// was compiled (so this should be unique across multiple devices for a user,
// alternatively you can manually set this to a GUID or other random value).
const char MQTT_CLIENTID[] PROGMEM  = AIO_KEY __DATE__ __TIME__;
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_CLIENTID, MQTT_USERNAME, MQTT_PASSWORD);
/****************************** Feeds ***************************************/

// Setup feeds for temperature & humidity
const char TEMPERATURE_FEED[] PROGMEM = AIO_USERNAME "/feeds/temperature";
Adafruit_MQTT_Publish temperature = Adafruit_MQTT_Publish(&mqtt, TEMPERATURE_FEED);

const char HUMIDITY_FEED[] PROGMEM = AIO_USERNAME "/feeds/humidity";
Adafruit_MQTT_Publish humidity = Adafruit_MQTT_Publish(&mqtt, HUMIDITY_FEED);

const char LAMP_FEED[] PROGMEM = AIO_USERNAME "/feeds/lamp";
Adafruit_MQTT_Subscribe lamp = Adafruit_MQTT_Subscribe(&mqtt, LAMP_FEED);

/*************************** Sketch Code ************************************/

void setup() {
  // Set lamp pin to output
  pinMode(lamp_pin, OUTPUT);
 
  // Init sensor
  dht.begin();

  Serial.begin(115200);
  Serial.println(F("Adafruit IO Example"));

  // Connect to WiFi access point.
  Serial.println(); Serial.println();
  delay(10);
  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());

  // listen for events on the lamp feed
  mqtt.subscribe(&lamp);
 
  // connect to adafruit io
  connect();

}


void loop() {
Adafruit_MQTT_Subscribe *subscription;

  // ping adafruit io a few times to make sure we remain connected
  if(! mqtt.ping(3)) {
    // reconnect to adafruit io
    if(! mqtt.connected())
      connect();
  }
// this is our 'wait for incoming subscription packets' busy subloop
  while (subscription = mqtt.readSubscription(1000)) {

    // we only care about the lamp events
    if (subscription == &lamp) {

      // convert mqtt ascii payload to int
      char *value = (char *)lamp.lastread;
      Serial.print(F("Received: "));
      Serial.println(value);

      // Apply message to lamp
      String message = String(value);
      message.trim();
      if (message == "ON") {digitalWrite(lamp_pin, HIGH);}
      if (message == "OFF") {digitalWrite(lamp_pin, LOW);}

sensor();

    }

  }


 
}

void sensor() {


  // Grab the current state of the sensor
  int humidity_data = (int)dht.readHumidity();
  int temperature_data = (int)dht.readTemperature();

  // Publish data
  if (! temperature.publish(temperature_data))
    Serial.println(F("Failed to publish temperature"));
  else
    Serial.println(F("Temperature published!"));

  if (! humidity.publish(humidity_data))
    Serial.println(F("Failed to publish humidity"));
  else
    Serial.println(F("Humidity published!"));

}
   // Repeat every 10 seconds
 // delay(10000);


void relay(){


}





// connect to adafruit io via MQTT
void connect() {

  Serial.print(F("Connecting to Adafruit IO... "));

  int8_t ret;

  while ((ret = mqtt.connect()) != 0) {

    switch (ret) {
      case 1: Serial.println(F("Wrong protocol")); break;
      case 2: Serial.println(F("ID rejected")); break;
      case 3: Serial.println(F("Server unavail")); break;
      case 4: Serial.println(F("Bad user/pass")); break;
      case 5: Serial.println(F("Not authed")); break;
      case 6: Serial.println(F("Failed to subscribe")); break;
      default: Serial.println(F("Connection failed")); break;
    }

    if(ret >= 0)
      mqtt.disconnect();

    Serial.println(F("Retrying connection..."));
    delay(5000);

  }

  Serial.println(F("Adafruit IO Connected!"));

}


- Tue Feb 09, 2016 9:59 am #40791 Anyone !

- Sun Apr 10, 2016 6:52 pm #45261 Hi there!

Not sure if I understand what are you trying to accomplish... I've an ESP01 reading temp and humidity and publishing to an MQTT server (LAN, Mosquitto). Will add a relay control soon using the same board, as you want.

The thing is I don't get why you need to wait for the DHT to update, probably this part of the code?

Code: Select all // Repeat every 10 seconds
 // delay(10000);


Waiting for 10secs will avoid reading values from the broker and therefore you won't be able to change the IO state. Is that what you meant?