PWM with a piezo buzzer,How can I change the PWM frequency?

[Mike]

I use the nrf51822qfaa,s110 v8.00,SDK V10.0. I use PWM module with a piezo buzzer. Now I need change the buzzer frequency, How can I change the PWM frequency?

for example:

/* 2-channel PWM, 200Hz, output on DK LED pins. */
app_pwm_config_t pwm1_cfg = APP_PWM_DEFAULT_CONFIG_2CH(5000L, BSP_LED_0, BSP_LED_1);

[Mahesh Venkitachalam]

The first parameter of APP_PWM_DEFAULT_CONFIG_2CH is the PWM period in microseconds.

So in the above code, 5000 us => 1000000/5000 Hz == 200 Hz. So to set the buzzer frequency to f, set the value as 1000000/f.

Also, if you just need PWM on one pin, you can use APP_PWM_DEFAULT_CONFIG_1CH.

[Mahesh Venkitachalam]

Here's a previous discussion on this topic: devzone.nordicsemi.com/.../