ESP01-DHT22

De Knowledge base

Première réalisation un capteur de température WIFI. Comme on va utiliser un DHT11-22 (ici un DHT22 car le DHT11 n'est pas du tout précis) on va par la même occasion un capteur d'humidité.

Le schema electrique

ESP01-DHT22.png

Les deux poussoirs avec leurs "pull-up" ne sont là que pour la programmation peut les retirer après.

le code

// www.arduinesp.com
//
// Plot DTH11 data on MARE.PINON-HEBERT.FR an ESP8266
// April 11 2015
// Author: Jeroen Beemster
// Website: www.arduinesp.com
 
#include <DHT.h>
#include <ESP8266WiFi.h>
 
// replace with your channel’s thingspeak API key,
String apiKey = "4XZ9NA14HQZ7BYD7";
const char* ssid = "ssid";
const char* password = "********";
 
const char* server = "mare.pinon-hebert.fr";
#define DHTPIN 2 // what pin we’re connected to
 
DHT dht(DHTPIN, DHT22);
WiFiClient client;
 
void setup() {
Serial.begin(115200);
delay(10);
dht.begin();
 
WiFi.begin(ssid, password);
 
Serial.println();
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");
 
}
 
void loop() {
 
float h = dht.readHumidity();
float t = dht.readTemperature();
if (isnan(h) || isnan(t)) {
  Serial.println("Failed to read from DHT sensor!");
  delay(2000);
  return;
}
 
if (client.connect(server,80)) { 
String postStr = apiKey;
postStr +="&field1=";
postStr += String(t);
postStr +="&field2=";
postStr += String(h);
postStr += "\r\n\r\n";
 
client.print("POST /update HTTP/1.1\n");
client.print("Host: api.thingspeak.com\n");
client.print("Connection: close\n");
client.print("X-THINGSPEAKAPIKEY: "+apiKey+"\n");
client.print("Content-Type: application/x-www-form-urlencoded\n");
client.print("Content-Length: ");
client.print(postStr.length());
client.print("\n\n");
client.print(postStr);
 
Serial.print("Temperature: ");
Serial.print(t);
Serial.print(" degrees Celcius Humidity: ");
Serial.print(h);
Serial.println("% send to Thingspeak");
}
client.stop();
 
Serial.println("Waiting...");
// thingspeak needs minimum 15 sec delay between updates
delay(10000);
}