pwm on timer4 does not work ?!?!?

3tnica · ‎2009-07-09

Posted on July 09, 2009 at 11:01

3tnica · ‎2011-05-17

Posted on May 17, 2011 at 12:17

Hello everyone I have sat trying to get pwm to work on timer4 channel 1, GPIOB6(have tried with timer 3 also). But the pin is just dead, (i can toggle the pin in gpio mode).

Code:

void main(void) { GPIO_InitTypeDef GPIO_InitStructure; TIM_TimeBaseInitTypeDef TIM4_TimeBaseInitStruct; TIM_OCInitTypeDef pwm4; RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4,ENABLE); RCC_APB1PeriphResetCmd(RCC_APB1Periph_TIM4,ENABLE); TIM4_TimeBaseInitStruct.TIM_Prescaler = 720; // 10us resolution TIM4_TimeBaseInitStruct.TIM_CounterMode = TIM_CounterMode_Up; TIM4_TimeBaseInitStruct.TIM_Period = 20000; // 200 ms TIM4_TimeBaseInitStruct.TIM_ClockDivision = TIM_CKD_DIV1; TIM_TimeBaseInit(TIM4,&TIM4_TimeBaseInitStruct); TIM_ClearFlag(TIM4, TIM_FLAG_Update); pwm4.TIM_OCMode=TIM_OCMode_PWM1; pwm4.TIM_Channel=TIM_Channel_1; pwm4.TIM_Pulse=TIM_OPMode_Single; pwm4.TIM_OCPolarity=TIM_OCPolarity_High; TIM_OCInit(TIM4,&pwm4); TIM_OC1PreloadConfig(TIM4, TIM_OCPreload_Enable); TIM_ARRPreloadConfig(TIM4,ENABLE); TIM_SetCounter(TIM4,0); TIM_SetAutoreload(TIM4, 0x00000FFF); TIM_SetCompare1(TIM4, 0x000000FF); TIM_ClearITPendingBit(TIM4,TIM_FLAG_Update); TIM_ITConfig(TIM4,TIM_IT_Update,ENABLE); TIM_PrescalerConfig(TIM4,720,TIM_PSCReloadMode_Update); TIM_Cmd(TIM4,ENABLE); //while .. . }

[ This message was edited by: 3tnica on 07-01-2009 16:07 ]

3tnica · ‎2011-05-17

Posted on May 17, 2011 at 12:17

Have tried to get pwm to work on timer1 aswell but its stonedead aswell, I have tried to set the channels to both out and AF configuration, but i guess it should be AF. Does anyone have any idea what could be wrong. Help would be highly appreciated.

Best Regards

loeffel · ‎2011-05-17

Posted on May 17, 2011 at 12:17

Hi

This code initalize a 1kHz 25% PWM at timer4 channel3

// definition

#define TIMER4_PERIODE ( 0x8CA0 ) /* 1ms -> 1kHz */

#define TIMER4_CH3_COMPARE ( 0x8CA0 / 4 ) /* 25% PWM */

void Timer4Init( void ) {

TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

TIM_OCInitTypeDef TIM_OCInitStructure;

GPIO_InitTypeDef GPIO_InitStructure;

// port B clock enable already done at ''peri.c''

// RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOB, ENABLE );

// configure timer4 channel3 as alternate function push-pull for PWM output

GPIO_InitStructure.GPIO_Pin = PB_DO_FAN_OUT;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;

GPIO_Init( GPIOB, &GPIO_InitStructure );

// enable TIM4 clock

RCC_APB1PeriphClockCmd( RCC_APB1Periph_TIM4, ENABLE );

// TIM4 configuration

TIM_TimeBaseStructure.TIM_Period = TIMER4_PERIODE; // overlow get detected at reload value of timer

TIM_TimeBaseStructure.TIM_Prescaler = 0x0; // 36MHz

TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;

TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

TIM_TimeBaseInit( TIM4, &TIM_TimeBaseStructure );

// PWM1 mode configuration for channel13

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;

TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;

TIM_OCInitStructure.TIM_Pulse = TIMER4_CH3_COMPARE;

TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;

TIM_OC3Init( TIM4, &TIM_OCInitStructure );

// enable capture compare unit of channel 3

TIM_OC3PreloadConfig( TIM4, TIM_OCPreload_Enable );

// enable reload mode

TIM_ARRPreloadConfig( TIM4, ENABLE );

// TIM4 enable counter

TIM_Cmd( TIM4, ENABLE );

}

[ This message was edited by: loeffel on 08-01-2009 10:51 ]

3tnica · ‎2011-05-17

Posted on May 17, 2011 at 12:17

Hello,

added these lines to ur code and got it working, also updated my library saw that it was from 2006 and newest was 2008 =/

TIM_SetAutoreload(TIM4, 0x00000FFF);

//New tim CC 1 value

TIM_SetCompare1(TIM4, 0x00006FF);

Thankyou for the help

3tnica · ‎2011-05-17

Posted on May 17, 2011 at 12:17

Trying ur example and can not get it to work.

Does alternate function on PB_DO_FAN_OUT mean that tim4_ch3 is used instead of as gpio?

Should also say that i am using the latest libraries from ST if that matters.

Best regards

loeffel · ‎2011-05-17

Posted on May 17, 2011 at 12:17

Hi

PB_DO_FAN_OUT stands for

#define PB_DO_FAN_OUT GPIO_Pin_8

I use A STM32F101VB at this MCU the Timer4 Channel3 AF Output is at PortB Pin8. At the datasheet of your MCU you will find the port and pin you have to use.

ozenozkaya · ‎2011-05-17

Posted on May 17, 2011 at 12:17

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);