Real Time Weather Monitoring Station
An Internet-of-Thing (IoT) component can be configured to collect real-time environmental data by integrating NodeMCU ESP8266 development board with a temperature and humidity sensor DHT11. The student used an Arduino IDE program to set up a small scale weather monitoring station which indicate the real-time and historical environmental data over the IoT platform ThingsBoard. The procedure is available here, which shows you how to set up the real time weather monitoring station with simple IoT components.
Components
|
IoT Server Platform |
Open Source IoT Platform - ThingsBoard |
|
IoT Controller (Available to borrow) |
|
|
Resources |
Procedures and Source Code (Arduino IDE code) ThingsBoard Installation Guide: Windows / other operating systems |
The temperature and humidity sensor send the data to ThingsBoard and the sensor data is plotted as graphical statistics.
Student
| Kemp Isabel Madeleine |
Department of Computing |
(April 2021)
Part 1 - Procedure
1) Board Setup
Note:
Each pin in the DHT11 has a special use, the 3 pins are called “SVG” collectively. The “S” is equivalent to “DATA”, which outputs both temperature and humidity through serial data. “V” is equivalent to “VCC”, a power of 3.5V to 5.5V is supplied. “G” is equivalent to “GND” or “GROUND” which is connected to the ground of the circuit.
Instructions:
i) Connect “S” to “D2”
ii) Connect “V” to “3V3”
iii) Connect “G” to “GND”
Node MCU Pinout
Completed
2) ThingsBoard Installation & Dashboard Setup
Installation Instruction: Windows/ other operating systems
Setup:
i) Download the JSON file
ii) Follow the instruction
3) Source Code
Download Arduino IDE code
4) Arduino Installation & Setup
Follow the instruction
Data Visualization
To access the telemetry data,
i) Go to “Devices” section
ii) Choose the device profile “ESP8266 Demo Device”
iii) Click “Latest telemetry”
To access the dashboard,
i) Go to “Dashboard”
ii) Click “ESP8266 DHT11: Temperature & Humidity Demo Dashboard”
iii) The output should be shown as below
Part 2 - Source Code for Arduino IDE
#include "DHT.h"
#include <ESP8266WiFi.h>
#include <ThingsBoard.h>
//input wifi credentials
#define WIFI_AP "Isabel Love Bella"
#define WIFI_PASSWORD "11112222"
int status = WL_IDLE_STATUS;
unsigned long lastSend;
//input thingsboard access token and IP address
#define TOKEN "ltJhusW41LTBuQIvBEnJ"
char thingsboardServer[] = "172.20.10.2";
WiFiClient wifiClient;
ThingsBoard tb(wifiClient);
// set up DHT11
#define DHTPIN 4
#define DHTTYPE DHT11
DHT dht(DHTPIN, DHTTYPE);
//Connect to WiFi
void setup() {
Serial.begin(115200);
dht.begin();
delay(10);
InitWiFi();
lastSend = 0;
}
//if can connect to thingsboard, proceed to getting temperature and humidity data
//if cannot connect to wifi, keep reconnecting
void loop() {
if ( !tb.connected() ) {
reconnect();
}
if ( millis() - lastSend > 1000 ) { // Update and send only after 1 seconds
getAndSendTemperatureAndHumidityData();
lastSend = millis();
}
tb.loop();
}
//getting the humidity and temperature data from DHT11
void getAndSendTemperatureAndHumidityData() {
Serial.println("Collecting temperature data.");
// Reading temperature or humidity takes about 250 milliseconds!
float humidity = dht.readHumidity();
// Read temperature as Celsius (the default)
float temperature = dht.readTemperature();
// Check if any reads failed and exit early (to try again).
if (isnan(humidity) || isnan(temperature)) {
Serial.println("Failed to read from DHT sensor!");
return;
}
Serial.println("Sending data to ThingsBoard:");
Serial.print("Humidity: ");
Serial.print(humidity);
Serial.print(" %\t");
Serial.print("Temperature: ");
Serial.print(temperature);
Serial.println(" *C ");
tb.sendTelemetryFloat("temperature", temperature);
tb.sendTelemetryFloat("humidity", humidity);
}
//connecting to wifi
//if connection fails, it will try to reconnect
void InitWiFi() {
Serial.println("Connecting to AP ...");
// attempt to connect to WiFi network
WiFi.begin(WIFI_AP, WIFI_PASSWORD);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("Connected to AP");
}
//when thingsboard connection fails, they will keep trying to reconnect.
//but if your wifi credentials are wrong, or unstable, it usually fails to reconnect.
//advice is to check your wifi credentials
//computer that runs arduino is using the same wifi credentials, as the one you typed on your computer
void reconnect() {
// Loop until we're reconnected
while (!tb.connected()) {
status = WiFi.status();
if ( status != WL_CONNECTED) {
WiFi.begin(WIFI_AP, WIFI_PASSWORD);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("Connected to AP");
}
Serial.print("Connecting to ThingsBoard node ...");
if ( tb.connect(thingsboardServer, TOKEN) ) {
Serial.println( "[DONE]" );
} else {
Serial.print( "[FAILED]" );
Serial.println( " : retrying in 5 seconds]" );
// Wait 5 seconds before retrying
delay( 5000 );
}
}
}
Part 3 - Reference
DHT11–Temperature and Humidity Sensor: https://components101.com/dht11-temperature-sensor
Humiture Sensor Module: http://wiki.sunfounder.cc/index.php?title=Humiture_Sensor_Module
NodeMCU: https://en.wikipedia.org/wiki/NodeMCU
Thingsboard: https://thingsboard.io/
Temperature upload over MQTT using ESP8266 and DHT22 sensor: https://thingsboard.io/docs/samples/esp8266/temperature/