Example Code for Arduino-PWM-driven DC Motors

Hardware Preparation

• DC Motors: x2
• Romeo Mini: x1

Software Preparation

1. Arduino IDE (download link: https://www.arduino.cc/en/software)
2. ESP32 board support package (version 2.0.0) installed via Arduino Boards Manager (follow the [Arduino Environment Configuration] steps)

Wiring Diagram

The module is powered by 5-12V. Choose an appropriate power supply voltage based on the motors.

Other Preparation Work

1. Add the ESP32 board URL to Arduino IDE: https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json
2. Install the ESP32 board support package (version 2.0.0) via Tools -> Board -> Boards Manager
3. Select "ESP32C3 Dev Module" from Tools -> Board
4. Configure USB CDC to "Enable" for serial monitor use
5. Select the correct serial port (press and hold BOOT + RST if the port is not recognized)

Sample Code

int EN1 = 0;   // M1 PWM control
int PH1 = 1;   // M1 direction control
int EN2 = 2;   // M2 PWM control
int PH2 = 10;  // M2 direction control

void setup() {
pinMode(EN1, OUTPUT);
pinMode(PH1, OUTPUT);
pinMode(EN2, OUTPUT);
pinMode(PH2, OUTPUT);
}

void loop() {
M1_Forward(200);
M2_Forward(200);
delay(5000);

M1_Backward(200);
M2_Backward(200);
delay(5000);
}

// ----- M1 control functions -----
void M1_Forward(int Speed) {
Speed ​​= constrain(Speed, 0, 255);
analogWrite(EN1, Speed);
digitalWrite(PH1, LOW);             // LOW = Forward rotation
}

void M1_Backward(int Speed) {
Speed ​​= constrain(Speed, 0, 255);
analogWrite(EN1, Speed);            // PWM value remains unchanged
digitalWrite(PH1, HIGH);            // HIGH = Reverse rotation
}

// ----- M2 control functions -----
void M2_Forward(int Speed) {
Speed ​​= constrain(Speed, 0, 255);
analogWrite(EN2, Speed);
digitalWrite(PH2, LOW);
}

void M2_Backward(int Speed) {
Speed ​​= constrain(Speed, 0, 255);
analogWrite(EN2, Speed);
digitalWrite(PH2, HIGH);
}

Result

Flash the sample program: motors M1 and M2 will first rotate forward simultaneously for 5 seconds, then rotate in reverse for 5 seconds.