ESP32 Basics

// Motor Driver PWM Outputs
#define MOTOR1_RPWM  4
#define MOTOR1_LPWM  16
#define MOTOR2_RPWM  17
#define MOTOR2_LPWM  18
#define MOTOR3_RPWM  19
#define MOTOR3_LPWM  21
#define MOTOR4_RPWM  22
#define MOTOR4_LPWM  23

// Motor Encoders (using input-capable pins)
#define ENC1_A  32
#define ENC1_B  33
#define ENC2_A  25
#define ENC2_B  26
#define ENC3_A  27
#define ENC3_B  14
#define ENC4_A  12
#define ENC4_B  13

// I2C for IMU
#define SDA_PIN  21  // Default I2C SDA
#define SCL_PIN  22  // Default I2C SCL

// Optional: Status LED
#define STATUS_LED  2  // Built-in LED

// Optional: Emergency Stop Button
#define ESTOP_BTN  15

// Set pin as output
pinMode(LED_PIN, OUTPUT);
digitalWrite(LED_PIN, HIGH);  // 3.3V
digitalWrite(LED_PIN, LOW);   // 0V

// Set pin as input
pinMode(BUTTON_PIN, INPUT_PULLUP);  // Enable internal pull-up
int state = digitalRead(BUTTON_PIN);

// Configure PWM
int channel = 0;       // PWM channel (0-15)
int frequency = 5000;  // 5kHz
int resolution = 8;    // 8-bit (0-255)

ledcSetup(channel, frequency, resolution);
ledcAttachPin(MOTOR_PIN, channel);

// Set duty cycle
ledcWrite(channel, 128);  // 50% duty cycle (128/255)

// Read analog value (0-4095 for 12-bit ADC)
int value = analogRead(ANALOG_PIN);

// Convert to voltage (0-3.3V)
float voltage = value * (3.3 / 4095.0);

// Set ADC resolution (9-12 bits)
analogReadResolution(12);  // Default

// Set ADC attenuation (voltage range)
analogSetAttenuation(ADC_11db);  // 0-3.3V range

#include <Wire.h>

void setup() {
  Wire.begin(SDA_PIN, SCL_PIN);  // Initialize I2C
  Wire.setClock(400000);         // 400kHz fast mode
}

// I2C Scanner
void scanI2C() {
  for (byte address = 1; address < 127; address++) {
    Wire.beginTransmission(address);
    byte error = Wire.endTransmission();
    
    if (error == 0) {
      Serial.print("I2C device found at 0x");
      if (address < 16) Serial.print("0");
      Serial.println(address, HEX);
    }
  }
}

volatile long encoderCount = 0;

void IRAM_ATTR encoderISR() {
  encoderCount++;
}

void setup() {
  pinMode(ENCODER_PIN, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(ENCODER_PIN), 
                  encoderISR, RISING);
}

#include <WiFi.h>

void setup() {
  WiFi.begin("SSID", "password");
  
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  
  Serial.println("\nConnected!");
  Serial.println(WiFi.localIP());
}

#include <BluetoothSerial.h>

BluetoothSerial SerialBT;

void setup() {
  SerialBT.begin("ESP32_Robot");  // Bluetooth device name
  Serial.println("Bluetooth started");
}

void loop() {
  if (SerialBT.available()) {
    char c = SerialBT.read();
    Serial.write(c);
  }
}