Plant Watering System with Soil Moisture Monitoring and MQTT Communication

11.12.2024 - Engine: Gemini

Indoor Plant Watering System with Soil Moisture Monitoring and MQTT Communication

Materials:

• Arduino (e.g., Uno or Nano)
• Soil moisture sensor (e.g., FC-28 or MH-Z19C)
• Water pump
• Relay module
• MQTT broker (e.g., Mosquitto)
• MQTT client (e.g., MQTT.js or Paho.js)

Setup:

1. Connect the soil moisture sensor to the Arduino:
   • Analog connection: VCC to 5V, GND to GND, Signal to A0
   • Digital connection: VCC to 5V, GND to GND, Signal to D2
2. Connect the water pump to the relay module:
   • VCC to 5V, GND to GND, Signal to IN
3. Connect the relay module to the Arduino:
   • VCC to 5V, GND to GND, IN1 to D3 (or other digital pin)
4. Connect the Arduino to the MQTT broker:
   • Ethernet shield or Wi-Fi module
5. Connect the MQTT client to the MQTT broker:
   • Install the MQTT client library (e.g., MQTT.js)
   • Establish connection to the broker

Functionality:

1. Soil Moisture Monitoring:
   • The soil moisture sensor measures the moisture content in the soil.
   • Readings are transmitted to the Arduino via the serial interface.
2. MQTT Communication:
   • The Arduino publishes soil moisture readings to the broker over MQTT.
   • The MQTT client subscribes to the topic to receive these readings.
3. Watering:
   • When soil moisture drops below a set threshold, the MQTT client sends a message to the Arduino to activate the water pump.
   • The Arduino turns on the relay module, activating the water pump.
4. Monitoring and Control:
   • The MQTT client can be used to monitor soil moisture in real-time and remotely control the watering system.

Code Sample:

MQTT Broker:

# Start Mosquitto broker
mosquitto -c /etc/mosquitto/mosquitto.conf

Arduino Code:

#include <MQTT.h>

const char *broker = "mqtt.example.com";
const char *topic = "soil-moisture";

MQTTClient client(broker, 1883);

void setup() {
  Serial.begin(9600);
  client.connect("arduino-1");
  client.subscribe(topic);
}

void loop() {
  int moisture = analogRead(A0);
  client.publish(topic, String(moisture));
}

MQTT Client Code (JavaScript):

const mqtt = require('mqtt');

const client = mqtt.connect('mqtt://mqtt.example.com');

client.on('connect', () => {
  client.subscribe(topic);
});

client.on('message', (topic, message) => {
  console.log('Soil moisture:', message.toString());
});