Circuit Documentation

Summary

This circuit is designed to monitor soil moisture levels and display the readings on a 0.96" OLED display. It also controls a water pump based on the moisture levels. The circuit uses an Arduino UNO as the main microcontroller, interfacing with a soil moisture sensor, an OLED display, a motor driver, and a water pump. The circuit is powered by multiple 9V batteries and includes switches for controlling the power and the water pump.

Component List

1. 0.96" OLED Display

   • Pins: GND, VDD, SCK, SDA
   • Description: A small OLED display used to show the soil moisture levels.
   • Purpose: Display soil moisture readings.

2. Water Pump

   • Pins: VCC, GND
   • Description: A small water pump used to water plants.
   • Purpose: Water plants based on soil moisture levels.

3. 9V Battery

   • Pins: -, +
   • Description: A 9V battery used to power various components in the circuit.
   • Purpose: Provide power to the circuit.

4. Rocker Switch

   • Pins: 1, 2
   • Description: A switch used to control the power to the Arduino UNO.
   • Purpose: Turn the Arduino UNO on and off.

5. L298N DC Motor Driver

   • Pins: OUT1, OUT2, 12V, GND, 5V, OUT3, OUT4, 5V-ENA-JMP-I, 5V-ENA-JMP-O, +5V-J1, +5V-J2, ENA, IN1, IN2, IN3, IN4, ENB
   • Description: A motor driver used to control the water pump.
   • Purpose: Control the water pump based on signals from the Arduino UNO.

6. Soil Moisture Module

   • Pins: positive, negative, Analog, Digital, Ground, VCC
   • Description: A sensor used to measure soil moisture levels.
   • Purpose: Provide soil moisture readings to the Arduino UNO.

7. Toggle Switch

   • Pins: L1, COM, L2
   • Description: A switch used to control the water pump.
   • Purpose: Manually control the water pump.

8. Arduino UNO

   • 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
   • Description: A microcontroller used to read sensor data and control the display and water pump.
   • Purpose: Main control unit of the circuit.

Wiring Details

0.96" OLED Display

• VDD connected to 5V on Arduino UNO
• GND connected to GND on Arduino UNO
• SCK connected to A5 on Arduino UNO
• SDA connected to A4 on Arduino UNO

Water Pump (Instance 1)

• VCC connected to OUT3 on L298N DC Motor Driver
• GND connected to OUT4 on L298N DC Motor Driver

Water Pump (Instance 2)

• VCC connected to COM on Toggle Switch
• GND connected to - on 9V Battery

9V Battery (Instance 1)

• + connected to 12V on L298N DC Motor Driver
• - connected to + on another 9V Battery

9V Battery (Instance 2)

• + connected to L2 on Toggle Switch
• - connected to GND on Arduino UNO

9V Battery (Instance 3)

• + connected to 1 on Rocker Switch
• - connected to 1 on another Rocker Switch

Rocker Switch (Instance 1)

• 1 connected to + on 9V Battery
• 2 connected to Vin on Arduino UNO

Rocker Switch (Instance 2)

• 1 connected to - on 9V Battery
• 2 connected to GND on Arduino UNO

L298N DC Motor Driver

• 5V connected to 3.3V on Arduino UNO
• GND connected to GND on Arduino UNO
• IN4 connected to Digital on Soil Moisture Module

Soil Moisture Module

• VCC connected to 5V on Arduino UNO
• Ground connected to GND on Arduino UNO
• Analog connected to A1 on Arduino UNO

Toggle Switch

• COM connected to VCC on Water Pump
• L2 connected to + on 9V Battery

Code Documentation

Arduino UNO Code

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

#define OLED_RESET 4
#define sensor A1

Adafruit_SSD1306 display(OLED_RESET);

void setup()
{
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C); // change the address (0x3C) as per need
  display.clearDisplay();
}

void loop() 
{ 
  int value = analogRead(sensor);
  int percent = map(value, 1024, 0, 0, 100);
  display.setTextSize(2);
  display.setTextColor(WHITE);
  display.setCursor(0,0);
  display.println("MOISTURE");
  display.print(percent);
  display.print("%");
  display.display();
  display.clearDisplay();
}

This code initializes the OLED display and reads the soil moisture level from the sensor connected to pin A1. The moisture level is then displayed on the OLED screen as a percentage. The display is updated continuously in the loop function.