WiFiDHT/WiFiDHTOLED.ino

#include <PubSubClient.h>
#include <ESP8266WiFi.h>
#include <DHTesp.h>

#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#include "credential.h"

#define SLEEP_MINUTES 1

DHTesp dht;

char* mqtt_server = "ashpool.lan";

WiFiClient wclient;

PubSubClient client(wclient, mqtt_server, 1883);

String nodeID;


#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

void setup() {
    Serial.begin(115200);
    nodeID = "ESP_" + String(ESP.getChipId(), 16);

    Serial.println("DHT MQTT Logger:" + nodeID + " Starting\n");

    dht.setup(D4, DHTesp::DHT22);

    Wire.begin(D6, D5);

    if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3c)) {
      Serial.println("SSD1306 allocation failed");
    }

    wifi_set_sleep_type(LIGHT_SLEEP_T);
    wifi();

    if (client.connect((char*) nodeID.c_str())) {
      Serial.println("Connected to MQTT broker");
    }

    display.display();
    display.drawPixel(10, 10, SSD1306_WHITE);
    display.clearDisplay();
    display.setTextSize(4);
    display.setTextColor(SSD1306_WHITE);
    
}

void wifi() {
  WiFi.persistent(false);
  WiFi.mode(WIFI_OFF);
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid_name, ssid_pass);  // Access WiFi, details from credential.h
   
  Serial.print("Connecting to ");
  Serial.print(ssid_name);
  Serial.print(" ...");

  while (WiFi.status() != WL_CONNECTED) {   // Wait for WiFi to connect
    delay(250);
    Serial.print(".");
  }

  Serial.println('\n');
  Serial.println("WiFi connection established");
  Serial.print("Device's IP address is ");
  Serial.println(WiFi.localIP());                        // Show device's IP address
}

template <typename T>
void publish(const char * topic, T msg)
{
  if (!client.connected()) {
      client.connect((char*) nodeID.c_str());
    }
  
  client.publish(nodeID + "/" + topic, String(msg));
  Serial.println(nodeID + "/" + topic + ": " + String(msg));
}

void loop() {
  delay(dht.getMinimumSamplingPeriod());
  
  Serial.println ( "------------------------" ) ;

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

  float h = dht.getHumidity();
  float t = dht.getTemperature();
  float hic = dht.computeHeatIndex(t, h, false);
  
  publish("temp", t);
  publish("relative_humidity", h);
  publish("heat_index", String(hic));

  display.clearDisplay();
  display.setCursor(10,0);
  display.println(String(t));
  display.display();

  delay(SLEEP_MINUTES * 60 * 1000L);
  
}