- Tue Jan 16, 2018 10:51 pm
#73200
I started a project with an esp8266 and my MQTT server. I wanted to try the sample code I found here for the DHT22 but changed it for the DHT11. Everything seems to work except it doesn't seem to be publishing the info to the MQTT (or the serial for that matter) its connecting to MQTT and receiving info on the topic but is quiet otherwise. I know the DHT works as i have had it working with a basic setup. please help
Code: Select all
/*
MQTT
DHT22, when "temperature, c" is sent it returns the temperature in celcius
when "humidity" is sent it returns the humidity as measured by the DHT22
the signal pin is connected to a pull-ip resistor and GPIO 2
*/
#include <ESP8266WiFi.h>
#include <PubSubClient.h>
#include <DHT.h>
#define DHTTYPE DHT11
#define DHTPIN D4
// Update these with values suitable for your network.
const char* ssid = "DZQ63";
const char* password = "HF27RST8TB8STDVB";
const char* mqtt_server = "192.168.1.38";
const char* clientID = "NodeMCUDevKit";
const char* outTopic = "Wemosout";
const char* inTopic = "Wemosin";
// Initialize DHT sensor
// NOTE: For WORKING with a faster than ATmega328p 16 MHz Arduino chip, like an ESP8266,
// you need to increase the threshold for cycle counts considered a 1 or 0.
// You can do this by passing a 3rd parameter for this threshold. It's a bit
// of fiddling to find the right value, but in general the faster the CPU the
// higher the value. The default for a 16mhz AVR is a value of 6. For an
// Arduino Due that runs at 84mhz a value of 30 works.
// This is for the ESP8266 processor on ESP-01
DHT dht(DHTPIN, DHTTYPE); // 11 works fine for ESP8266
float humidity = dht.readHumidity();
float temp_f = dht.readTemperature(true);
// Generally, you should use "unsigned long" for variables that hold time
unsigned long previousMillis = 0; // will store last temp was read
const long interval = 2000; // interval at which to read sensor
WiFiClient espClient;
PubSubClient client(espClient);
char msg[50];
void setup_wifi() {
delay(10);
// We start by connecting to a WiFi network
Serial.println();
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
}
void callback(char* topic, byte* payload, unsigned int length) {
// Conver the incoming byte array to a string
payload[length] = '\0'; // Null terminator used to terminate the char array
String message = (char*)payload;
Serial.print("Message arrived on topic: [");
Serial.print(topic);
Serial.print("], ");
Serial.println(message);
if(message == "temperature, f"){
gettemperature();
Serial.print("Sending temperature:");
Serial.println(temp_f);
dtostrf(temp_f, 2, 2, msg);
client.publish(outTopic, msg);
} else if (message == "humidity"){
gettemperature();
Serial.print("Sending humidity:");
Serial.println(humidity);
dtostrf(humidity, 2, 2, msg);
client.publish(outTopic, msg);
}
}
void reconnect() {
// Loop until we're reconnected
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
// Attempt to connect
if (client.connect(clientID)) {
Serial.println("connected");
// Once connected, publish an announcement...
client.publish(outTopic, clientID);
// ... and resubscribe
client.subscribe(inTopic);
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
// Wait 5 seconds before retrying
delay(5000);
}
}
}
void setup() {
Serial.begin(115200);
setup_wifi();
client.setServer(mqtt_server, 1883);
client.setCallback(callback);
dht.begin(); // initialize temperature sensor
}
void loop() {
if (!client.connected()) {
reconnect();
}
client.loop();
}
void gettemperature() {
// Wait at least 2 seconds seconds between measurements.
// if the difference between the current time and last time you read
// the sensor is bigger than the interval you set, read the sensor
// Works better than delay for things happening elsewhere also
unsigned long currentMillis = millis();
if(currentMillis - previousMillis >= interval) {
// save the last time you read the sensor
previousMillis = currentMillis;
// Reading temperature for humidity takes about 250 milliseconds!
// Sensor readings may also be up to 2 seconds 'old' (it's a very slow sensor)
humidity = dht.readHumidity(); // Read humidity (percent)
temp_f = dht.readTemperature(true); // Read temperature as Celcius
// Check if any reads failed and exit early (to try again).
if (isnan(humidity) || isnan(temp_f)) {
Serial.println("Failed to read from DHT sensor!");
return;
}
}
}
