Posted on October 01, 2014 at 08:29Hi everyone,
I want to use my encoder with 32bit general purpose timer TIM2 on my STM32F429 Discovery board. I've connected pin PA0 ( TIM2_CH1) and pin PA1 ( TIM2_CH2) to my encoder, but it didn't work. The encoder count value returned only 0 and 1. Then I changed pin PA1 to PB3 ( TIM2_CH2), and it works normally. I've tested on my friend's STM32F4 Discovery board, it also works normally when I connected PA0 and PA1 to my encoder. But I don't know why it doesn't work with my board.
Here's my code:
void RCC_Config()
{
// Enable GPIO clock
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA|RCC_AHB1Periph_GPIOB,ENABLE);
// Enable SYS clock
//RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG,ENABLE);
//Enable TIM
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);
}
void GPIO_Config()
{
GPIO_InitTypeDef GPIO_InitStructure;
//Encoder chanel
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;
GPIO_Init(GPIOA, &GPIO_InitStructure);
//Connect Timer Pins to AF Pins
GPIO_PinAFConfig(GPIOA,GPIO_PinSource1,GPIO_AF_TIM2);
GPIO_PinAFConfig(GPIOA,GPIO_PinSource0,GPIO_AF_TIM2);
}
void Encoder_Config()
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_Period = 0xFFFFFFFF;
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
TIM_ARRPreloadConfig(TIM2, ENABLE);
TIM_SetAutoreload(TIM2,0xFFFFFFFF);
//Debounce filter
// TIM_ICInitStruct.TIM_Channel=TIM_Channel_1|TIM_Channel_2;
// TIM_ICInitStruct.TIM_ICFilter=0x3;
// TIM_ICInitStruct.TIM_ICSelection=TIM_ICSelection_DirectTI;
// TIM_ICInit(TIM2, &TIM_ICInitStruct);
// set them up as encoder inputs
TIM_EncoderInterfaceConfig (TIM2, TIM_EncoderMode_TI12, TIM_ICPolarity_Rising, TIM_ICPolarity_Rising);
// turn on the timer/counters
TIM_ClearFlag(TIM2,TIM_FLAG_Update);
TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);
TIM_SetCounter(TIM2,0);
TIM_Cmd (TIM2, ENABLE);
}
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_4);
NVIC_Structure.NVIC_IRQChannel = TIM2_IRQn;
NVIC_Structure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_Structure.NVIC_IRQChannelSubPriority = 0;
NVIC_Structure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_Structure);
}
void TIM2_IRQHandler(void)
{
if (TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET)
{
if((TIM2->CR1)&0x10) // true = giam
NumEncoder -= 0xFFFFFFFF;
else
NumEncoder += 0xFFFFFFFF;
TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
}
}
Can anyone help me? I would appreciate any help in determining what my errors are. Thank you! And sorry for my bad English.
