nrf51822 PWM Library on mBed

[StudioNeat]

Hello, I am trying to use the 'nrf51-pwm-library' on mBed with a nrf51822 on RedBearLab Nano.

I copied the nrf_pwm.h/c files and they compile, but I never get any sort of signal out of the PWM pin. (Pin 19 on the RBL Nano is an on board LED.)

I assume there is something simple I am missing?

Here is the main.c code:

#include "mbed.h"
#include "BLEDevice.h"

#include "nrf_gpio.h"
#include "nrf_delay.h"
#include "nrf_pwm.h"




void pwm_init()
{
    nrf_pwm_config_t pwm_config = PWM_DEFAULT_CONFIG;
    
    pwm_config.mode             = PWM_MODE_BUZZER_255;
    pwm_config.num_channels     = 1;
    pwm_config.gpio_num[0]      = 19;
    
    // Initialize the PWM library
    nrf_pwm_init(&pwm_config);       
}


int main(void)
{    
    
    pwm_init();
    
    while (true)
    {
        nrf_pwm_set_value(0, 0);
        
        nrf_delay_us(500000);  
        
        nrf_pwm_set_value(0, 127);  
        
        nrf_delay_us(500000); 
        
        nrf_pwm_set_value(0, 255);  
        
        nrf_delay_us(500000); 
    }

}

[Stian Røed Hafskjold]

I was not able to make this work either. I think it has to do with how mbed handles interrupts. It stops in the call to NVIC_SetPendingIRQ(PWM_IRQn).

However, mbed has a PwmOut class that is easy to set up. You can read about it here: developer.mbed.org/.../PwmOut. The example code provided works out of the box with the nRF51-DK.

[Bharat]

Hi Stian

I am working on nRF51-DK on Mbed IDE & using the sample code link : https://os.mbed.com/handbook/PwmOut

When enabled PwmOut in my project, PWM is working ok standalone but other pheripherals like UART are not working.

It would be grateful if you suggest to resolve this issue.

Regards

Bharat Gopani