Posted on June 13, 2013 at 05:35Clive,
I'm using stm32F407 for quadrature encoder counter.
encoder counter is two by using TIM2 and TIM5 for 32bit timer count.
the gpio port are gpioA15, gpioB3 for TIM2 and gpioA0, gpio A1 for TIM5.
I need to get the encoder count data up to X4.
My target linear scale encoder makes pulses every 0.5um and the moving speed is 1000mm/s.
When I tested, the count number is OK on 200mm/s speed. but the count number is not correct when the speed is 250mm/s.
So, I would like to the stm32f407's quadrature encoder counting ability.
Any Idears?
please let me have advice to solve this problem.
Thank you.
Here is the code
--------------------------------------------------------------------------
/*
* definitions for the quadrature encoder pins
*/
// Encoder 1. Channels
#define ENCLA_PIN GPIO_Pin_15
#define ENCLA_GPIO_PORT GPIOA
#define ENCLA_GPIO_CLK RCC_AHB1Periph_GPIOA
#define ENCLA_SOURCE GPIO_PinSource15
#define ENCLA_AF GPIO_AF_TIM2
#define ENCLB_PIN GPIO_Pin_3
#define ENCLB_GPIO_PORT GPIOB
#define ENCLB_GPIO_CLK RCC_AHB1Periph_GPIOB
#define ENCLB_SOURCE GPIO_PinSource3
#define ENCLB_AF GPIO_AF_TIM2
// Encoder 2. Channels
#define ENCRA_PIN GPIO_Pin_0 //GPIO_Pin_6
#define ENCRA_GPIO_PORT GPIOA //GPIOB
#define ENCRA_GPIO_CLK RCC_AHB1Periph_GPIOA
#define ENCRA_SOURCE GPIO_PinSource0
#define ENCRA_AF GPIO_AF_TIM5
#define ENCRB_PIN GPIO_Pin_1 //GPIO_Pin_7
#define ENCRB_GPIO_PORT GPIOA //GPIOB
#define ENCRB_GPIO_CLK RCC_AHB1Periph_GPIOA
#define ENCRB_SOURCE GPIO_PinSource1
#define ENCRB_AF GPIO_AF_TIM5
// determine the timers to use
#define ENCL_TIMER TIM2
#define ENCL_TIMER_CLK RCC_APB1Periph_TIM2
#define ENCR_TIMER TIM5
#define ENCR_TIMER_CLK RCC_APB1Periph_TIM5
void main()
{
EncodersInit
( );
while();
}
void EncodersInit (void)
{
//GPIO_InitTypeDef GPIO_InitStructure;
// turn on the clocks for each of the ports needed
RCC_AHB1PeriphClockCmd (ENCLA_GPIO_CLK, ENABLE);
RCC_AHB1PeriphClockCmd (ENCLB_GPIO_CLK, ENABLE);
RCC_AHB1PeriphClockCmd (ENCRA_GPIO_CLK, ENABLE);
RCC_AHB1PeriphClockCmd (ENCRB_GPIO_CLK, ENABLE);
// now configure the pins themselves
// they are all going to be inputs with pullups
GPIO_StructInit (&GPIO_InitStructure);
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_InitStructure.GPIO_Pin = ENCLA_PIN;
GPIO_Init (ENCLA_GPIO_PORT, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = ENCLB_PIN;
GPIO_Init (ENCLB_GPIO_PORT, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = ENCRA_PIN;
GPIO_Init (ENCRA_GPIO_PORT, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = ENCRB_PIN;
GPIO_Init (ENCRB_GPIO_PORT, &GPIO_InitStructure);
// Connect the pins to their Alternate Functions
GPIO_PinAFConfig (ENCLA_GPIO_PORT, ENCLA_SOURCE, ENCLA_AF);
GPIO_PinAFConfig (ENCLB_GPIO_PORT, ENCLB_SOURCE, ENCLB_AF);
GPIO_PinAFConfig (ENCRA_GPIO_PORT, ENCRA_SOURCE, ENCRA_AF);
GPIO_PinAFConfig (ENCRB_GPIO_PORT, ENCRB_SOURCE, ENCRB_AF);
// Timer peripheral clock enable
RCC_APB1PeriphClockCmd (ENCL_TIMER_CLK, ENABLE);
RCC_APB1PeriphClockCmd (ENCR_TIMER_CLK, ENABLE);
// set them up as encoder inputs
// set both inputs to rising polarity to let it use both edges
TIM_EncoderInterfaceConfig (ENCL_TIMER, TIM_EncoderMode_TI12,
TIM_ICPolarity_Rising,
TIM_ICPolarity_Rising);
TIM_SetAutoreload (ENCL_TIMER, 0xFFFFFFFF);
TIM_EncoderInterfaceConfig (ENCR_TIMER, TIM_EncoderMode_TI12,
TIM_ICPolarity_Rising,
TIM_ICPolarity_Rising);
TIM_SetAutoreload (ENCR_TIMER, 0xFFFFFFFF);
// turn on the timer/counters
TIM_Cmd (ENCL_TIMER, ENABLE);
TIM_Cmd (ENCR_TIMER, ENABLE);
EncodersReset();
}
void EncodersReset (void)
{
__disable_irq();
TIM_SetCounter (ENCL_TIMER, 0);
TIM_SetCounter (ENCR_TIMER, 0);
__enable_irq();
}
