nRF51822 PWM strange behavior

[Vrabec]

Hi.

I'm using latest version of nrf51-pwm-library to test if PWM works fine, but unfortunately, it's not. I have very simple program which should fade LED from 255 to 0 in infinite loop, but instead fading, I can see LED light on 100% and then turn off (blink instead fade). When I debug, I notice, LED is on (without any fading) when i > 0 and LED is off when i == 0.

Any suggestions? Btw no softdevice is used so far.

This is how my code look like:

#include <stdbool.h>
#include <stdint.h>
#include "nrf.h"
#include "nrf_gpio.h"
#include "nrf_delay.h"
#include "nrf_pwm.h"
#include "boards.h"

int main(void)
{
    nrf_pwm_config_t pwm_config = PWM_DEFAULT_CONFIG;
    
    pwm_config.mode             = PWM_MODE_LED_255;
    pwm_config.num_channels     = 1;
    pwm_config.gpio_num[0]      = 9;   
    
    // Initialize the PWM library
    nrf_pwm_init(&pwm_config);

		for(uint8_t i = 255; i >= 0; i--){
			nrf_pwm_set_value(0, i);
			nrf_delay_ms(100);
		}
}

[Stefan Birnir Sverrisson]

Hi Vrabec

Thank you for your question.

I can not reproduce the issue with your code, using nrf_pwm.h, SDK 7.0.1 and nRF51-DK. What SDK version and hardware are you using?

[Vrabec]

Thank you for detailed explanation. I already ordered nRF51822 rev. 3.