PWM driving a Buzzer

[vn2000]

I am using SDK V15 with an nRF52DK and Keil compiler.

I have difficulty finding an example to use a GPIO to drive a Piezo Buzzer. The requirement is very simple: use a GPIO to generate a sound frequency of about 18 Khz to the Buzzer.

The PWM examples in the SDK are so convoluted and difficult to understand. I looked at other examples in the forum and many are outdated, some cannot be compiled, others are compiled but crashed, etc..

I would appreciate if someone can provide a simple example to drive a Buzzer at 18 Khz.

[vn2000]

Since I was running the buzzer at 10Khz, I can see the signal with the duty cycle varying during the buzz. After it is complete, I can still see the same 10Khz signal but with a fixed duty cycle at around. 10%.

Anyway I used the app_pwm_disable() and it goes back to be quiet. 

The issue is resolved. Thank you for your help.