Project Documentation

ESP32-Based Rain and Obstacle Detection System with Relay Motor Control

Circuit Documentation

Summary

The circuit is designed to monitor environmental conditions such as voltage levels and rain presence while controlling a DC motor based on sensor inputs. It includes a voltage sensing mechanism, rain detection, and an IR sensor for object detection. The circuit uses an ESP32 microcontroller to process sensor data and control a 4-channel relay module that interfaces with a DC motor. Power management is handled by a 12V battery, a step-down power converter, and a solar charge controller connected to a solar panel. The circuit also includes a voltage sensor, an IR sensor, two rain sensor modules (detection and control boards), and passive components like a resistor and an electrolytic capacitor.

Component List

Power Components

12V Battery (mini): Provides the main power source for the circuit.
12v to 5v Step Down Power Converter: Converts the 12V battery voltage to a regulated 5V output.
Solar Charge Controller: Manages the charging of the battery from the solar panel.
Solar Panel: Generates electrical power from sunlight to charge the battery.

Sensors

Voltage Sensor DC: Measures the voltage level of the battery.
IR Sensor: Detects the presence of objects using infrared light.
YL-83 Rain Sensor - Detection Board: Detects rainwater.
YL-83 Rain Sensor - Control Board: Processes the signal from the detection board and provides digital and analog outputs.

Actuators

DC Motor: Converts electrical energy into mechanical motion.
Relay 4 Channel 5v: Electrically operated switches that control the power to the DC motor.

Microcontroller

ESP32 38 PINS: A microcontroller with Wi-Fi and Bluetooth capabilities that reads sensor data and controls the relays.

Passive Components

Electrolytic Capacitor: Used for filtering and stabilizing the power supply.
Resistor: Limits the current or divides voltages within the circuit.

Wiring Details

Power Components

12V Battery (mini):
- + to voltage sensor VCC, Relay 4 Channel 5v NO1, NO2, and step-down converter VIN+.
- - to step-down converter VIN-, DC Motor pin 2, voltage sensor GND, Relay 4 Channel 5v NO3, NC3, and another 12V Battery (mini) -.
12v to 5v Step Down Power Converter:
- VIN 9v-36v not connected.
- VIN+ to DC Motor pin 1 and Relay 4 Channel 5v COM1.
- VIN- to 12V Battery (mini) -.
- USB OUTPUT 5V not connected.
- 5v OUTPUT to voltage sensor vcc and Electrolytic Capacitor -.
- GND to voltage sensor gnd, Relay 4 Channel 5v GND.
Solar Charge Controller:
- No specific pin connections listed, but connected to solar panel and Relay 4 Channel 5v COM2, COM3.
Solar Panel:
- + to Solar Charge Controller.
- - to Solar Charge Controller.

Sensors

Voltage Sensor DC:
- signal not connected.
- vcc to step-down converter 5v OUTPUT.
- gnd to step-down converter GND.
- GND to 12V Battery (mini) -.
- VCC to 12V Battery (mini) +.
IR Sensor:
- out not connected.
- gnd to ESP32 GND.
- vcc to YL-83 Rain Sensor - Control Board VCC.
YL-83 Rain Sensor - Detection Board:
- POS to YL-83 Rain Sensor - Control Board POS.
- NEG to YL-83 Rain Sensor - Control Board NEG.
YL-83 Rain Sensor - Control Board:
- VCC to IR Sensor vcc.
- GND to ESP32 GND.
- DO not connected.
- AO not connected.
- POS to YL-83 Rain Sensor - Detection Board POS.
- NEG to YL-83 Rain Sensor - Detection Board NEG.

Actuators

DC Motor:
- pin 1 to step-down converter VIN+.
- pin 2 to 12V Battery (mini) -.
Relay 4 Channel 5v:
- GND to step-down converter GND.
- IN1 not connected.
- IN2 not connected.
- IN3 not connected.
- IN4 not connected.
- VCC to Resistor pin1.
- COM1 to step-down converter VIN+.
- COM2 to Solar Charge Controller.
- COM3 to Solar Charge Controller.
- COM4 not connected.
- NO1 to 12V Battery (mini) +.
- NO2 to 12V Battery (mini) +.
- NO3 to 12V Battery (mini) -.
- NO4 not connected.
- NC1 to 12V Battery (mini) +.
- NC2 to 12V Battery (mini) +.
- NC3 to 12V Battery (mini) -.
- NC4 not connected.

Microcontroller

ESP32 38 PINS:
- GND to IR Sensor gnd, YL-83 Rain Sensor - Control Board GND.

Passive Components

Electrolytic Capacitor:
- + to Resistor pin2.
- - to step-down converter 5v OUTPUT.
Resistor:
- pin1 to Relay 4 Channel 5v VCC.
- pin2 to Electrolytic Capacitor +.

Documented Code

#include <Arduino.h>

// Pin Definitions
const int voltageSensorPin = 34;    // Voltage sensor analog input
const int rainSensorPin = 35;       // Rain sensor analog input
const int irSensorPin = 32;         // IR sensor digital input
const int relay1Pin = 26;           // Relay channel 1 for DC motor
const int relay2Pin = 27;           // Relay channel 2 (for future use)
const int relay3Pin = 14;           // Relay channel 3 (for future use)
const int relay4Pin = 12;           // Relay channel 4 (for future use)

// Voltage sensor calibration constants
const float voltageReference = 3.3; // Reference voltage of ESP32 ADC
const int resolution = 4095;        // ADC resolution
const float voltageDividerRatio = 5.7; // Ratio of the voltage divider used in the sensor

void setup() {
  // Initialize serial communication
  Serial.begin(115200);

  // Set pin modes
  pinMode(voltageSensorPin, INPUT);
  pinMode(rainSensorPin, INPUT);
  pinMode(irSensorPin, INPUT);
  pinMode(relay1Pin, OUTPUT);
  pinMode(relay2Pin, OUTPUT);
  pinMode(relay3Pin, OUTPUT);
  pinMode(relay4Pin, OUTPUT);

  // Initialize relays to be off
  digitalWrite(relay1Pin, LOW);
  digitalWrite(relay2Pin, LOW);
  digitalWrite(relay3Pin, LOW);
  digitalWrite(relay4Pin, LOW);
}

void loop() {
  // Voltage sensing
  int voltageSensorValue = analogRead(voltageSensorPin);
  float batteryVoltage = (voltageSensorValue * voltageReference / resolution) * voltageDividerRatio;
  Serial.print("Battery Voltage: ");
  Serial.println(batteryVoltage);

  // Rain detection
  int rainSensorValue = analogRead(rainSensorPin);
  Serial.print("Rain Sensor Value: ");
  Serial.println(rainSensorValue);

  // IR sensor detection
  int irSensorValue = digitalRead(irSensorPin);
  Serial.print("IR Sensor State: ");
  Serial.println(irSensorValue);

  // Motor control based on rain and IR sensor input
  if (rainSensorValue > 500) {
    // If rain detected, stop the motor
    digitalWrite(relay1Pin, LOW);
    Serial.println("Rain detected, motor stopped.");
  } else if (irSensorValue == HIGH) {
    // If no rain and IR sensor detects an object, start the motor
    digitalWrite(relay1Pin, HIGH);
    Serial.println("IR detected, motor running.");
  } else {
    // If no rain and no IR detection, keep motor off
    digitalWrite(relay1Pin, LOW);
    Serial.println("No rain, no IR, motor stopped.");
  }

  // Add delays to reduce serial output spamming
  delay(1000);
}

This code is designed to run on an ESP32 microcontroller. It initializes the necessary pins for reading from the voltage and rain sensors, as well as for controlling the relays connected to the DC motor. The loop function reads