Posted on May 17, 2011 at 14:23Hi bap68
I am not sure why your PWM output is not working, but I have it working on my board using TIM3 ch1 - not controlling motors though. So the best I can do for you now is to show you how I did it - may be that would help. Below you will find some code extracts of how I did it.
Good luck.
Cheers,
Gawie
Init PWM output mode:
// Init PWM output mode
// The external signal is connected to TIM3 CH1 pin REMAPPED to (PC.06),
GPIO_InitTypeDef GPIO_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
TIM_OCInitTypeDef TIM_OCInitStruct;
TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct;
TIM_DeInit(TIM3);
TIM_OCStructInit(&TIM_OCInitStruct);
TIM_OC1Init(TIM3, &TIM_OCInitStruct);
TIM_TimeBaseStructInit(&TIM_TimeBaseInitStruct);
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseInitStruct);
// Full Remap TIM3 to PC6-9
GPIO_PinRemapConfig(GPIO_FullRemap_TIM3, ENABLE);
// TIM3 clock enable
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
// GPIOC clock enable
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);
// Enable the TIM3 global Interrupt
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
// Configure TIM3 channel 1 pin (PC.6) as output
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);
// TIM3 disable counter
TIM_Cmd(TIM3, DISABLE);
// Disable the Update Interrupt Request
TIM_ITConfig(TIM3, TIM_IT_Update, DISABLE);
Start PWM output:
// Start PWM Output
TIM_OCInitTypeDef TIM_OCInitStructure;
TIM_ARRPreloadConfig(TIM3, DISABLE);
TIM3->ARR = 0;
// Set Output Compare Chan1 on TIM3
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 0;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC1Init(TIM3, &TIM_OCInitStructure);
// Enable preload of period (ARR)
TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);
// Enable preload of pulse (CCR1)
TIM_ARRPreloadConfig(TIM3, ENABLE);
// Start Period width that will be loaded on next Update Event
TIM3->ARR = u16Period;
// Start Pulse width that will be loaded on next Update Event
TIM3->CCR1 = u16Pulse;
// Clear any pending interrupts before when enable it
TIM_ClearITPendingBit(TIM3, TIM_IT_Update);
// Enable the Update Interrupt Request
TIM_ITConfig(TIM3, TIM_IT_Update, ENABLE);
// Force an Update event to start sequence
TIM_GenerateEvent(TIM3, TIM_EventSource_Update);
// TIM enable counter
TIM_Cmd(TIM3, ENABLE);
Interrupt Service Routine:
if(TIM_GetITStatus(TIM3, TIM_IT_Update) == SET)
{
// Clear interrupt bit
TIM_ClearITPendingBit(TIM3, TIM_IT_Update);
// New Period width that will be loaded on next Update Event
TIM3->ARR = u16Period;
// New Pulse width that will be loaded on next Update Event
TIM3->CCR1 = u16Pulse;
}
You will need some condition to stop PWM output - will be unique to you
// Disable the Update Interrupt Request
TIM_ITConfig(TIM3, TIM_IT_Update, DISABLE);
