RE: Cannot drive LED using PWM

jswcomkr — Wed, 18 Dec 2019 14:47:57 GMT

Hello.

Thank you for reply.

I've solved problem.

void pwmInit(void)
{
	NRF_PWM0->PSEL.OUT[0] = 23 ;
	NRF_PWM0->PSEL.OUT[1] = 24 ; 
	NRF_PWM0->ENABLE = 0x00000001;
	NRF_PWM0->MODE = 0x00000000;
	NRF_PWM0->PRESCALER = 0x00000000;
	NRF_PWM0->COUNTERTOP = 32000;
	NRF_PWM0->DECODER = 0x00000002;
	NRF_PWM0->LOOP = 0x00000000;
	NRF_PWM0->SEQ[0].REFRESH = 0;
	NRF_PWM0->SEQ[0].ENDDELAY = 0;
	NRF_PWM0->SEQ[0].PTR = (uint32_t)(pwmDuty);
	NRF_PWM0->SEQ[0].CNT = 4;
	NRF_PWM0->TASKS_SEQSTART[0] = 1;
}

it works after remove <nrf_drv_pwm.h>

Thank you.

RE: Cannot drive LED using PWM

Edvin — Wed, 18 Dec 2019 11:10:45 GMT

Hello,

Have you tried to analyze the PWM signal using e.g. a saleae logic analyzer? Is it actually a PWM signal on the LED? Or is it simply ON?

Note that on the LEDs on the DK it may be difficult to tell the difference between 90% and 100%, while it is easy to tell the difference between 0% and 10%, or 10% and 20%