Circuit Documentation

Summary

This document provides a comprehensive overview of a circuit designed to control a set of gearmotors using an ESP32 microcontroller and an L298N DC motor driver. The circuit includes various components such as gearmotors, a 12V battery, switches, an IR sensor, an MQ-3 alcohol sensor, a TP4056 charging module, a polymer lithium-ion battery, buzzers, LEDs, and resistors. The ESP32 microcontroller is programmed to interact with these components, enabling control and feedback mechanisms for a potential robotic or automated system.

Component List

Microcontrollers

• ESP32 (30 pin): A microcontroller with WiFi and Bluetooth capabilities, featuring a wide range of GPIO pins for interfacing with various sensors and actuators.

Motors

• Gearmotor DC Wheels (Right and Left): DC motors with gear reduction that are typically used for driving wheels in robotic applications.

Power Supply

• Battery 12V: A 12-volt battery providing the main power source for the motors and motor driver.
• Polymer Lithium Ion Battery - 850mAh: A rechargeable battery used to power the ESP32 and other low-power components.
• TP4056: A charging module designed for lithium-ion batteries, providing safe charging and power management.

Control

• L298N DC motor driver: An H-bridge motor driver capable of driving two DC motors or one stepper motor.
• Rocker Switch: A switch used to control the power flow from the battery to the motor driver and charging module.

Sensors

• IR Sensor: An infrared sensor used for proximity detection or line tracking.
• MQ-3 Alcohol Sensor: A sensor used to detect alcohol levels in the air.

Indicators

• Buzzer: An audible signaling device.
• LED (Red): Light-emitting diodes used as visual indicators.

Passive Components

• Resistor (330 Ohms): Resistors used to limit current to the LEDs.

Wiring Details

ESP32 (30 pin)

• D33: Connected to L298N DC motor driver ENB.
• D25: Connected to L298N DC motor driver IN4.
• D26: Connected to L298N DC motor driver IN3.
• D27: Connected to L298N DC motor driver IN2.
• D14: Connected to L298N DC motor driver IN1.
• D12: Connected to L298N DC motor driver ENA.
• GND: Common ground with the battery, buzzer, L298N DC motor driver, IR sensor, MQ-3 alcohol sensor, and TP4056.
• Vin: Connected to L298N DC motor driver 5V.
• D18: Connected to a 330 Ohm resistor leading to an LED.
• D5: Connected to a 330 Ohm resistor leading to an LED.
• D4: Connected to the buzzer.
• 3V3: Power supply for the IR sensor and MQ-3 alcohol sensor.

Gearmotors

• DC Wheels Right and Left: Connected to the L298N DC motor driver's output pins.

Battery 12V

• + (Positive): Connected to one terminal of the rocker switch.
• - (Negative): Common ground with the circuit.

Rocker Switch

• Terminal 1: Connected to the 12V battery positive.
• Terminal 2: Connected to the L298N DC motor driver 12V input and the TP4056 B+ pin.

L298N DC motor driver

• OUT1, OUT2, OUT3, OUT4: Connected to the gearmotor DC wheels.
• 12V: Powered through the rocker switch from the 12V battery.
• GND: Common ground with the circuit.
• 5V: Power output to the ESP32 Vin pin.
• ENA, ENB, IN1, IN2, IN3, IN4: Controlled by the ESP32 GPIO pins.

IR Sensor

• Out: Connected to the ESP32 GPIO pin.
• GND: Common ground with the circuit.
• VCC: Powered by the ESP32 3V3 pin.

MQ-3 Alcohol Sensor

• A0: Connected to the ESP32 GPIO pin.
• GND: Common ground with the circuit.
• VCC: Powered by the ESP32 3V3 pin.

TP4056

• OUT-: Connected to the ESP32 GND.
• OUT+: Connected to the ESP32 Vin.
• B-: Connected to the polymer lithium-ion battery GND.
• B+: Connected to the polymer lithium-ion battery VCC through a rocker switch.

Polymer Lithium Ion Battery - 850mAh

• GND: Connected to the TP4056 B-.
• VCC: Connected to the TP4056 B+ through a rocker switch.

Buzzer

• PIN: Connected to the ESP32 GPIO pin.
• GND: Common ground with the circuit.

LED (Red)

• Cathode: Connected to the common cathode of another LED.
• Anode: Connected to a 330 Ohm resistor which is then connected to the ESP32 GPIO pin.

Resistor (330 Ohms)

• Pin 1: Connected to the ESP32 GPIO pin.
• Pin 2: Connected to the anode of the LED.

Documented Code

ESP32 (30 pin) - sketch.ino

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

}

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

}

Note: The provided code is a template and does not include specific functionality. It needs to be populated with the logic to control the motors, read sensors, and activate indicators based on the application requirements.