Servo

Module: arduino::driver::motor::servo

Minimal hobby servo driver for ATmega328P / Arduino Uno.

Timer1 is used

The servo driver uses Timer1, so normal PWM on D9 and D10 is taken over while servos are attached.

Pins

Supported servo pins:

• D9
• D10

Constants

• MIN_PULSE_US = 544
• MAX_PULSE_US = 2400
• DEFAULT_PULSE_US = 1500

Functions

macro void attach(ServoPin pin);
macro void detach(ServoPin pin);
macro void write_angle(ServoPin pin, int angle);
macro void write_us(ServoPin pin, ushort pulse_us);

attach

Enables servo output on the pin and moves it to the default center pulse, 1500 us.

detach

Stops driving the servo pin.

write_angle

Moves a servo using an angle in degrees. Values are clamped to 0..180.

write_us

Moves a servo using a pulse width in microseconds. Values are clamped to 544..2400.

Example

module servo_example;

import arduino::driver::motor::servo;
import arduino::time;

fn void main() @export("start") {
    servo::attach(D9);

    while (true) {
        servo::write_angle(D9, 0);
        time::delay_ms(1000);

        servo::write_angle(D9, 90);
        time::delay_ms(1000);

        servo::write_angle(D9, 180);
        time::delay_ms(1000);
    }
}