ESP32 Forum

Code: Select all

#include <driver/mcpwm.h>

#define SERVO_MIN_PULSEWIDTH_US (1000) // Minimum pulse width in microsecond
#define SERVO_MAX_PULSEWIDTH_US (2000) // Maximum pulse width in microsecond
#define SERVO_MAX_DEGREE        (90)   // Maximum angle in degree upto which servo can rotate

#define SERVO_PULSE_GPIO        (21)   // GPIO connects to the PWM signal line

uint32_t convert_servo_angle_to_duty_us(int angle)
{
    return (angle + SERVO_MAX_DEGREE) * (SERVO_MAX_PULSEWIDTH_US - SERVO_MIN_PULSEWIDTH_US) / (2 * SERVO_MAX_DEGREE) + SERVO_MIN_PULSEWIDTH_US;
}

void setup() {
  Serial.begin(115200);
  mcpwm_gpio_init(MCPWM_UNIT_0, MCPWM0A, SERVO_PULSE_GPIO);

  mcpwm_config_t pwm_config;
  pwm_config.frequency = 50;
  pwm_config.cmpr_a = 0;
  pwm_config.counter_mode = MCPWM_UP_COUNTER;
  pwm_config.duty_mode = MCPWM_DUTY_MODE_0;

  mcpwm_init(MCPWM_UNIT_0, MCPWM_TIMER_0, &pwm_config);
}

void loop() {
  for (int angle = -SERVO_MAX_DEGREE; angle < SERVO_MAX_DEGREE; angle++) {
      Serial.printf("Angle of rotation: %d\n", angle);
      mcpwm_set_duty_in_us(MCPWM_UNIT_0, MCPWM_TIMER_0, MCPWM_OPR_A, convert_servo_angle_to_duty_us(angle));
      delay(100); //Add delay, since it takes time for servo to rotate, generally 100ms/60degree rotation under 5V power supply
  }
  delay(1000);
}