Client.ino

/*
Client code to get temperature and humidity
*/
#include <DHT.h>
#include <ESP8266WiFi.h>
#include <ESP8266HTTPClient.h>
#define DHTPIN 2

// AP Wi-Fi credentials
const char* ssid = "ESP_Sensor_NTW";
const char* password = "espsensorntw";

// Local ESP web-server address
String serverHost = "http://192.168.4.1/feed";
String data;

int counter = 0;

float h;
float t;

// Static network configuration
IPAddress ip(192, 168, 4, 4);
IPAddress gateway(192, 168, 4, 1);
IPAddress subnet(255, 255, 255, 0);

DHT dht(DHTPIN, DHT11);
WiFiClient client;

void setup() {
  ESP.eraseConfig();
  WiFi.persistent(false);
  Serial.begin(115200);
  Serial.println();
  Serial.println("**************************");
  Serial.println("**************************");
  Serial.println("******** BEGIN ***********");
  Serial.println("- start DHT sensor");
  dht.begin();
  delay(500);
  Serial.println("- set ESP STA mode");
  WiFi.mode(WIFI_STA);
  Serial.println("- connecting to wifi");
  WiFi.config(ip, gateway, subnet); 
  WiFi.begin(ssid, password);
  Serial.println("");
  while (WiFi.status() != WL_CONNECTED) {
    if(counter > 20){
       Serial.println("- can't connect, going to sleep");    
       delay(500);
    }
    Serial.print(".");
    counter++;
  }
  
  Serial.println("- wifi connected");
  Serial.println("- read DHT sensor");
  readDHTSensor();
  Serial.println("- build DATA stream string");
  buildDataStream();
  Serial.println("- send GET request");
  sendHttpRequest();
  Serial.println();
  Serial.println("- end of update");
  Serial.println("**************************");
  Serial.println("**************************");
}

void sendHttpRequest() {
  HTTPClient http;
  http.begin(serverHost);
  http.addHeader("Content-Type", "application/x-www-form-urlencoded");
  http.POST(data);
  http.writeToStream(&Serial);
  http.end();
}

void readDHTSensor() {
  delay(200);
  h = dht.readHumidity();
  t = dht.readTemperature();
  if (isnan(h) || isnan(t)) {
    t = 0.00;
    h = 0.00;
  }
  Serial.println("- temperature read : "+String(t));
  Serial.println("- humidity read : "+String(h));
}

void buildDataStream() {
  data = "temp1=";
  data += String(t);
  data += "&hum1=";
  data += String(h);
  Serial.println("- data stream: "+data);
}


void loop() {
  Serial.println("- read DHT sensor");
  readDHTSensor();
  Serial.println("- build DATA stream string");
  buildDataStream();
  Serial.println("- send GET request");
  sendHttpRequest();
  Serial.println();
  Serial.println("- end of update");
  delay(10000);
  }