Circuit Documentation

Summary

This circuit is designed to monitor soil moisture levels using multiple soil moisture sensors, display the data on an I2C LCD screen, and control a water pump via a relay. The system is powered by an Arduino UNO microcontroller, which reads data from the sensors and controls the relay and LCD screen. A DHT11 sensor is also included to monitor temperature and humidity.

Component List

1. Arduino UNO

   • Description: Microcontroller board based on the ATmega328P.
   • Pins: UNUSED, IOREF, Reset, 3.3V, 5V, GND, Vin, A0, A1, A2, A3, A4, A5, SCL, SDA, AREF, D13, D12, D11, D10, D9, D8, D7, D6, D5, D4, D3, D2, D1, D0

2. Soil Moisture Sensor

   • Description: Sensor to measure soil moisture levels.
   • Pins: VCC, GND, SIG

3. 9V Battery

   • Description: Power source for the water pump.
   • Pins: -, +

4. 12V SINGLE CHANNEL RELAY

   • Description: Relay module to control the water pump.
   • Pins: NC, COM, NO, IN, GND, VCC

5. Mini Diaphragm Water Pump

   • Description: Water pump to irrigate the soil.
   • Pins: Positive (+), Negative (-)

6. I2C LCD 16x2 Screen

   • Description: LCD screen to display sensor data.
   • Pins: SCL, SDA, VCC (5V), GND, VDD, VO, RS, RW, E, D0, D1, D2, D3, D4, D5, D6, D7, BLA, BLK

7. DHT11 Sensor V2

   • Description: Sensor to measure temperature and humidity.
   • Pins: GND, DAT, VCC

Wiring Details

Arduino UNO

• 3.3V connected to VCC of all Soil Moisture Sensors.
• 5V connected to VCC of 12V SINGLE CHANNEL RELAY, DHT11 Sensor V2, and I2C LCD 16x2 Screen.
• GND connected to GND of all Soil Moisture Sensors, 12V SINGLE CHANNEL RELAY, DHT11 Sensor V2, and I2C LCD 16x2 Screen.
• A0 connected to SIG of Soil Moisture Sensor 1.
• A1 connected to SIG of Soil Moisture Sensor 2.
• A2 connected to SIG of Soil Moisture Sensor 3.
• A4 connected to SDA of I2C LCD 16x2 Screen.
• A5 connected to SCL of I2C LCD 16x2 Screen.
• D7 connected to DAT of DHT11 Sensor V2.
• D8 connected to IN of 12V SINGLE CHANNEL RELAY.

Soil Moisture Sensor 1

• VCC connected to 3.3V of Arduino UNO.
• GND connected to GND of Arduino UNO.
• SIG connected to A0 of Arduino UNO.

Soil Moisture Sensor 2

• VCC connected to 3.3V of Arduino UNO.
• GND connected to GND of Arduino UNO.
• SIG connected to A1 of Arduino UNO.

Soil Moisture Sensor 3

• VCC connected to 3.3V of Arduino UNO.
• GND connected to GND of Arduino UNO.
• SIG connected to A2 of Arduino UNO.

9V Battery

• - connected to Negative (-) of Mini Diaphragm Water Pump.
• + connected to COM of 12V SINGLE CHANNEL RELAY.

12V SINGLE CHANNEL RELAY

• VCC connected to 5V of Arduino UNO.
• GND connected to GND of Arduino UNO.
• IN connected to D8 of Arduino UNO.
• COM connected to + of 9V Battery.
• NO connected to Positive (+) of Mini Diaphragm Water Pump.

Mini Diaphragm Water Pump

• Positive (+) connected to NO of 12V SINGLE CHANNEL RELAY.
• Negative (-) connected to - of 9V Battery.

I2C LCD 16x2 Screen

• SCL connected to A5 of Arduino UNO.
• SDA connected to A4 of Arduino UNO.
• VCC (5V) connected to 5V of Arduino UNO.
• GND connected to GND of Arduino UNO.

DHT11 Sensor V2

• VCC connected to 5V of Arduino UNO.
• GND connected to GND of Arduino UNO.
• DAT connected to D7 of Arduino UNO.

Documented Code

Arduino UNO Code (sketch.ino)

void setup() {
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:

}

Additional Documentation (documentation.txt)