/*0001*/ void ENC_Init(void)
/*0002*/ {
/*0003*/ TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
/*0004*/ TIM_ICInitTypeDef TIM_ICInitStructure;
/*0005*/
/*0006*/ /* Encoder unit connected to TIM3, 4X mode */
/*0007*/ GPIO_InitTypeDef GPIO_InitStructure;
/*0008*/ NVIC_InitTypeDef NVIC_InitStructure;
/*0009*/
/*0010*/ /* TIM3 clock source enable */
/*0011*/ RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
/*0012*/ /* Enable GPIOA, clock */
/*0013*/ RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
/*0014*/
/*0015*/ GPIO_StructInit(&GPIO_InitStructure);
/*0016*/ /* Configure PA.06,07 as encoder input */
/*0017*/ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
/*0018*/ GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
/*0019*/ GPIO_Init(GPIOA, &GPIO_InitStructure);
/*0020*/
/*0021*/ /* Enable the TIM3 Update Interrupt */
/*0022*/ NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
/*0023*/ NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = TIMx_PRE_EMPTION_PRIORITY;
/*0024*/ NVIC_InitStructure.NVIC_IRQChannelSubPriority = TIMx_SUB_PRIORITY;
/*0025*/ NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
/*0026*/ NVIC_Init(&NVIC_InitStructure);
/*0027*/
/*0028*/ /* Timer configuration in Encoder mode */
/*0029*/ TIM_DeInit(ENCODER_TIMER);
/*0030*/ TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
/*0031*/
/*0032*/ TIM_TimeBaseStructure.TIM_Prescaler = 0x0; // No prescaling
/*0033*/ TIM_TimeBaseStructure.TIM_Period = ENCODER_TIM_PERIOD;
/*0034*/ TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
/*0035*/ TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
/*0036*/ TIM_TimeBaseInit(ENCODER_TIMER, &TIM_TimeBaseStructure);
/*0037*/
/*0038*/ TIM_EncoderInterfaceConfig(ENCODER_TIMER, TIM_EncoderMode_TI12,
/*0039*/ TIM_ICPolarity_Rising, TIM_ICPolarity_Rising);
/*0040*/ TIM_ICStructInit(&TIM_ICInitStructure);
/*0041*/ TIM_ICInitStructure.TIM_ICFilter = ICx_FILTER;
/*0042*/ TIM_ICInit(ENCODER_TIMER, &TIM_ICInitStructure);
/*0043*/
/*0044*/ // Clear all pending interrupts
/*0045*/ TIM_ClearFlag(ENCODER_TIMER, TIM_FLAG_Update);
/*0046*/ TIM_ITConfig(ENCODER_TIMER, TIM_IT_Update, ENABLE);
/*0047*/ //Reset counter
/*0048*/ TIM2->CNT = COUNTER_RESET;
/*0049*/
/*0050*/ // ENC_Clear_Speed_Buffer();
/*0051*/
/*0052*/ TIM_Cmd(ENCODER_TIMER, ENABLE);
/*0053*/ }
/*0054*/
/*0055*/ 以下为获取一次计数值，此算法来自lxyppc，可以规避超过16位的情况，具体细节见http://bbs.21ic.com/viewthread.php?tid=110623的讨论
/*0056*/
/*0057*/ s16 ENC_Get_Electrical_Angle(void)
/*0058*/ {
/*0059*/ static u16 lastCount = 0;
/*0060*/
/*0061*/ u16 curCount = ENCODER_TIMER->CNT;
/*0062*/ s32 dAngle = curCount - lastCount;
/*0063*/
/*0064*/ if(dAngle >= MAX_COUNT){
/*0065*/ dAngle -= ENCODER_TIM_PERIOD;
/*0066*/ }else if(dAngle < -MAX_COUNT){
/*0067*/ dAngle += ENCODER_TIM_PERIOD;
/*0068*/ }
/*0069*/ lastCount = curCount;
/*0070*/ return (s16)dAngle;
/*0071*/ }
/*0072*/
/*0073*/ 以下为系统滴答的初始化和中断函数
/*0074*/
/*0075*/ void TB_Init(void)
/*0076*/ {
/*0077*/ /* Setup SysTick Timer for 10 msec interrupts */
/*0078*/ if (SysTick_Config(SystemFrequency / 100))
/*0079*/ {
/*0080*/ /* Capture error */
/*0081*/ while (1);
/*0082*/ }
/*0083*/ }
/*0084*/
/*0085*/ void SysTick_Handler(void)
/*0086*/ {
/*0087*/ /*if (hTimebase_display_500us != 0)
|*0088*| {
|*0089*| hTimebase_display_500us --;
|*0090*| }
|*0091*| */
/*0092*/ if (hSpeedMeas_Timebase_500us !=0)
/*0093*/ {
/*0094*/ hSpeedMeas_Timebase_500us--;
/*0095*/ }
/*0096*/ else
/*0097*/ {
/*0098*/ hSpeedMeas_Timebase_500us = SPEED_SAMPLING_TIME;
/*0099*/
/*0100*/ CurrentCount += ENC_Get_Electrical_Angle();
/*0101*/
/*0102*/ //ENC_Calc_Average_Speed must be called ONLY every SPEED_MEAS_TIMEBASE ms
/*0103*/ //ENC_Calc_Average_Speed();
/*0104*/ }
/*0105*/ } |
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