Circuit Documentation

Summary

This circuit is designed to interface an ESP32 microcontroller with a rotary potentiometer, a pushbutton, an LED, and a resistor. The ESP32 is powered by a 5V battery and communicates via Bluetooth to act as a joystick. The potentiometer is used to control the joystick's X-axis, while the pushbutton can be used for additional input. The LED is connected through a resistor to indicate the status of the circuit.

Component List

1. 5V Battery

   • Description: Power source for the circuit.
   • Pins: Positive, Negative

2. ESP32 38 PINS

   • Description: Microcontroller with Bluetooth capabilities.
   • Pins: GND, 23, 22/SCL, 1, 2, 21/SDA, 19, 18, 5, 17/TX2, 16/RX2, 4, 0, 15, D1, D0, CLK, 3V3, EN, VP, VN, 34, 35, 32, 33, 25, 26, 27, 14, 12, 13, D2, D3, 11, 5V/VIN

3. PR-Rotary Potentiometer

   • Description: Variable resistor used to control the joystick's X-axis.
   • Pins: GND, OUT, VCC

4. LED: Two Pin (red)

   • Description: Indicator LED.
   • Pins: Cathode, Anode

5. Resistor

   • Description: Limits current to the LED.
   • Pins: Pin1, Pin2
   • Properties:
     • Resistance: 200 Ohms

6. Pushbutton

   • Description: User input button.
   • Pins: Pin 3 (out), Pin 4 (out), Pin 1 (in), Pin 2 (in)

Wiring Details

5V Battery

• Positive connected to ESP32 38 PINS pin 5V/VIN
• Negative connected to ESP32 38 PINS pin GND

ESP32 38 PINS

• GND connected to:
  • 5V Battery pin Negative
  • PR-Rotary Potentiometer pin GND
  • LED: Two Pin (red) pin Cathode
  • Pushbutton pin Pin 4 (out)
• 5V/VIN connected to 5V Battery pin Positive
• 23 connected to Resistor pin Pin2
• 18 connected to Pushbutton pin Pin 1 (in)
• 3V3 connected to PR-Rotary Potentiometer pin VCC
• 25 connected to PR-Rotary Potentiometer pin OUT

PR-Rotary Potentiometer

• GND connected to ESP32 38 PINS pin GND
• OUT connected to ESP32 38 PINS pin 25
• VCC connected to ESP32 38 PINS pin 3V3

LED: Two Pin (red)

• Cathode connected to ESP32 38 PINS pin GND
• Anode connected to Resistor pin Pin1

Resistor

• Pin1 connected to LED: Two Pin (red) pin Anode
• Pin2 connected to ESP32 38 PINS pin 23

Pushbutton

• Pin 4 (out) connected to ESP32 38 PINS pin GND
• Pin 1 (in) connected to ESP32 38 PINS pin 18

Code Documentation

Code for ESP32 Microcontroller

#include <BleGamepad.h>

BleGamepad bleGamepad("ESP32 Joystick", "ESP32 Dev Kit", 100); // Device name and information

const int potPin = 25; // ADC pin for potentiometer

void setup() {
  Serial.begin(9600);
  Serial.println("Starting BLE Joystick...");
  
  // Initialize BLE joystick
  bleGamepad.begin();
}

void loop() {
  if (bleGamepad.isConnected()) {
    // Read potentiometer value
    int rawValue = analogRead(potPin);

    // Map value to joystick range (-32767 to 32767)
    int joystickValue = map(rawValue, 0, 4095, -32767, 32767);

    // Send X-axis value
    bleGamepad.setAxes(joystickValue, 0, 0, 0, 0, 0); // Set X-axis, other axes 0

    // Small delay for transmission stability
    delay(10);
  }
}

Code File Information

• File Name: sketch.ino
• Description: This code initializes the ESP32 as a Bluetooth joystick. It reads the value from the rotary potentiometer and maps it to the X-axis of the joystick. The joystick value is then sent via Bluetooth.