TIM4 上的 STM32 旋转编码器配置 [英] STM32 Rotary Encoder config on TIM4

问题描述

我正在尝试将 TIM4 用于我的 STM32F4DISCOVERY 板上的正交编码器输入.这是我的代码:

I'm trying to use TIM4 for quadrature encoder input on my STM32F4DISCOVERY board. Here is my code :

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);

GPIO_InitTypeDef GPIO_InitStructure;
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_InitStructure.GPIO_Pin = GPIO_Pin_6| GPIO_Pin_7;
GPIO_Init(GPIOB, &GPIO_InitStructure);

GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_TIM4);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource7, GPIO_AF_TIM4);

/* Configure the timer */
TIM_EncoderInterfaceConfig(TIM4, TIM_EncoderMode_TI12, TIM_ICPolarity_Rising, TIM_ICPolarity_Rising);

/* TIM4 counter enable */
TIM_Cmd(TIM4, ENABLE);

遗憾的是，当我转动编码器时，TIM4->CNT 计数器不会移动.我与 TIM8 完美配合.这是工作 TIM8 和不工作 TIM4 的完整代码:https://gist.github.com/nraynaud/5082298

sadly, the TIM4->CNT counter won't move when I turn the encoder. I works perfectly with TIM8. Here is the full code of the working TIM8 and the not working TIM4 : https://gist.github.com/nraynaud/5082298

我在手动移动编码器后通过在 gdb 中打印 rT2() 来检查.

I check by printing rT2() in gdb after moving the encoder by hand.

推荐答案

我使用 STM32F407 从 3 个光学编码器读取编码器计数.我使用的是 ChibiOS RTOS，所以定时器结构体与 ST Peripheral 库定时器结构体略有不同，但信息基本相同.以下是我如何配置实际定时器的寄存器:

I have used an STM32F407 to read encoder counts from 3 optical encoders. I am using ChibiOS RTOS so the timer struct is slightly different from the ST Peripheral library timer struct, but the information is basically the same. Here is how I configure the registers of the actual timers:

stm32_tim_t * encoderTimers[3] = {STM32_TIM8, STM32_TIM3, STM32_TIM4};
for (auto timer : encoderTimers) {
  timer->SMCR = 3;          // Encoder mode 3
  timer->CCER = 0;          // rising edge polarity
  timer->ARR = 0xFFFF;      // count from 0-ARR or ARR-0
  timer->CCMR1 = 0xC1C1;    // f_DTS/16, N=8, IC1->TI1, IC2->TI2
  timer->CNT = 0;           // Initialize counter
  timer->EGR = 1;           // Generate an update event
  timer->CR1 = 1;           // Enable the counter
}

此外，请确保启用 RCC 的 APB1 或 APB2 寄存器中的定时器外设.类似的东西:

Also, make sure you enable the timer peripherals in the APB1 or APB2 registers of the RCC. Something like:

RCC->APB1ENR |= ((1 <<  2)  // TIM4  --  Front wheel angle measurement
             |   (1 <<  1));// TIM3  --  Steer angle measurement

最后，您需要确保正确配置 GPIO 设置.这意味着为备用功能配置 GPIO.

Finally, you need to make sure you configure the GPIO settings correctly. This means configuring the GPIO for Alternate Function.

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