pls help; pwm TIM3 from PC6 doesnt work

ozenozkaya · ‎2009-09-08

Posted on September 09, 2009 at 02:47

ozenozkaya · ‎2011-05-17

Posted on May 17, 2011 at 13:17

hi, i am trying to use TIM3 Channel 1 as PWM from PC6 as AF; but the brigthness doesnt change. what am i doing wrong?? pls help...

here is the code:

RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM3 , ENABLE);

RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);

GPIO_InitTypeDef GPIO_InitStructure;

TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

TIM_OCInitTypeDef TIM_OCInitStructure;

//this pin functions as AF; when remapping

GPIO_PinRemapConfig(GPIO_FullRemap_TIM3, ENABLE);

/*GPIOC Configuration: TIM3 channel 1 */

/* make sure that C port is opened in RCC*/

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOC, &GPIO_InitStructure);

TIM_Cmd(TIM3, DISABLE);

TIM_ARRPreloadConfig(TIM3, ENABLE);

/* Time base configuration */

TIM_TimeBaseStructure.TIM_Period = 999;

TIM_TimeBaseStructure.TIM_Prescaler = 0;

TIM_TimeBaseStructure.TIM_ClockDivision = 0;

TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

/* PWM1 Mode configuration: Channel1 */

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;

TIM_OCInitStructure.TIM_Channel = TIM_Channel_1;

TIM_OCInitStructure.TIM_Pulse = 500;

TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;

TIM_OCInit(TIM3, &TIM_OCInitStructure);

TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);

TIM_ARRPreloadConfig(TIM3, ENABLE);

/* TIM3 enable counter */

TIM_Cmd(TIM3, ENABLE);

TIM_SetCompare1(TIM3,0x10);

psd · ‎2011-05-17

Posted on May 17, 2011 at 13:17

Hi,

I am using the timers now too, but I don't use the library calls because they are too bloated for my application.

I noticed that you did not enable the output pins on channel 1 (TIM3_CCER). Maybe that is your problem.

Currently I got timer 3 channel 1 working in PWM mode without the remap, but it does not work when I turn on the remap, even though I set the GPIO pins to AFO push-pull for both possible destinations, and turned on the AFIO peripheral clock. Do you have ideas about this ?

Thanks,

Phil

psd · ‎2011-05-17

Posted on May 17, 2011 at 13:17

Hi,

In my case my problem was caused by not turning off the SWJ, which conflicted with PB4 in my chip. You may want to check this for your chip.

Phil