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How To: PWM

Pulse Width Modulation (PWM) is a method to create an analog-like signal from the microcontroller's digital output. It achieves that by fast toggling of the pin with a different ratio of logic HIGH and LOW. This ratio is called the duty cycle.

Please check the Core Module pinout to see which pins allow PWM.

9 pins can be used as PWM pins:

  TWR_PWM_P0
  TWR_PWM_P1
  TWR_PWM_P2
  TWR_PWM_P3
  TWR_PWM_P6
  TWR_PWM_P7
  TWR_PWM_P8
  TWR_PWM_P12
  TWR_PWM_P14

References​

Duty Cycle​

The duty cycle stands for how long should the pin be in the HIGH state, by changing this number you will achieve different analog-like outputs.

The values range from 0-255 where 0 means always LOW and 255 means always HIGH

info

This is just a simple example that will enable PWM signal on P6, P7 and P8 outputs. Every output has a different duty cycle: 180, 210 and 255.

Run PWM on Pins Code Example

void application_init()
{
    twr_pwm_init(TWR_PWM_P6);
    twr_pwm_set(TWR_PWM_P6, 180);
    twr_pwm_enable(TWR_PWM_P6);

    twr_pwm_init(TWR_PWM_P7);
    twr_pwm_set(TWR_PWM_P7, 210);
    twr_pwm_enable(TWR_PWM_P7);

    twr_pwm_init(TWR_PWM_P8);
    twr_pwm_set(TWR_PWM_P8, 255);
    twr_pwm_enable(TWR_PWM_P8);
}