K60的正交解码

dlyt03 · 发表于 2013-2-21 21:01:26

参考下

xxyz987 · 发表于 2013-2-27 20:02:00

larry 发表于 2012-4-2 13:51
我这里的情况指电磁组的双路脉冲检测方案

摄像头组的也用这两路捕捉，可以吗？
/*功能：FTM1、FTM2模块双路正交脉冲计数；
引脚：PTA12、PTA13、PTA10、PTA11
内容：初始化FTM1、FTM2的正交解码功能；*/

陈胜利 · 发表于 2013-3-16 22:10:54

#include "lptmr.h"

//==========================================================================
//函数名称: lptmr_internal_ref_input
//函数返回: 无
//参数说明: 无
//注意: 内部参考时钟4分频作为模块时钟，使用ptc5号引脚，alt2通道
//功能概要: 清上次寄存器的值便于本次设置
//==========================================================================
void lptmr_internal_ref_input()
{
  unsigned int compare_value=15625; //4 seconds with prescale=8 and 2Mhz fast clock

  //Reset LPTMR module
  lptmr_clear_registers();
  /* Enable LPT Module */
  SIM_SCGC5|=SIM_SCGC5_LPTIMER_MASK;

  //打开c口5号引脚的相应功能
  SIM_SCGC5 |= SIM_SCGC5_PORTC_MASK; //Turn on PORTA clock
  PORTC_PCR5=PORT_PCR_MUX(0x4); //Use ALT2 on PTC 5

  // /* Ensure Internal Reference Clock is Enabled *  /
  MCG_C1|=MCG_C1_IRCLKEN_MASK;
  //Enable fast internal ref clock by setting MCG_C2[IRCS]=1
  //If wanted to use 32Khz slow mode, set MCG_C2[IRCS]=0 instead
  MCG_C2|=MCG_C2_IRCS_MASK;

  /* Configure LPTMR */
  LPTMR0_CMR=LPTMR_CMR_COMPARE(compare_value);  //Set compare value
  LPTMR0_PSR=LPTMR_PSR_PCS(0x0)|LPTMR_PSR_PRESCALE(0x1);  //Use internal clock prescaled by8
  LPTMR0_CSR=LPTMR_CSR_TPS(0x2)|LPTMR_CSR_TMS_MASK; //use 2模块(LPT0_ALT2)(c口5引脚) 计数模式

  LPTMR0_CSR|=LPTMR_CSR_TEN_MASK; //开始计数 //Turn on LPT with default settings

}

//==========================================================================
//函数名称: lptmr_pulse_counter
//函数返回: 无
//参数说明: 输入值为要使用的引脚号
//注意: 使用1khz的LPO时钟进行计数，使用与低速状态
//功能概要: 清上次寄存器的值便于本次设置
//==========================================================================
void lptmr_pulse_counter(char pin_select)
{
  unsigned int compare_value=1000;

  //Reset LPTMR module
  lptmr_clear_registers();

  //Set up GPIO
  if(pin_select==LPTMR_ALT1)
  {
SIM_SCGC5 |= SIM_SCGC5_PORTA_MASK; //Turn on PORTA clock
PORTA_PCR19=PORT_PCR_MUX(0x6); //Use ALT6 on PTA19

//printf("Testing ALT1 pin on PORTA19\n");
//printf("\tTWR-K70F120M: ALT1 is conected to pin 18 on J15\n");
  }
  else if(pin_select==LPTMR_ALT2)
  {
SIM_SCGC5 |= SIM_SCGC5_PORTC_MASK; //Turn on PORTC clock
PORTC_PCR5=PORT_PCR_MUX(0x4); //Use ALT2 on PTC5

  }

  LPTMR0_PSR=LPTMR_PSR_PCS(0x1)|LPTMR_PSR_PBYP_MASK; //Use LPO clock but bypass glitch filter
  LPTMR0_CMR=LPTMR_CMR_COMPARE(compare_value);  //Set compare value
  LPTMR0_CSR=LPTMR_CSR_TPS(pin_select)|LPTMR_CSR_TMS_MASK; //Set LPT to use the pin selected, and put in pulse count mode, on rising edge (default)

  //printf("Press any key to start pulse counter\n");
  //in_char(); //wait for keyboard press

  LPTMR0_CSR|=LPTMR_CSR_TEN_MASK; //Turn on LPT


}

//=================================================================================
//函数名： get_counter_value
//功能  ：读编码器的计数值
//注意  ：电压不稳，频率过低可能丢脉冲
//输入  ：无
//输出  ：编码器的计数值

// On each read of the LPTMR counter register, software must first write to the  *
//LPTMR counter register with any value. This will synchronize and register the  *
// current value of the LPTMR counter register into a temporary register. The *
//contents of the temporary register are returned on each read of the LPTMR    *
// counter register.
//===============================================================================
uint16 get_counter_value()
{
  LPTMR0_CNR=0x1;
  return LPTMR0_CNR;
}

//==========================================================================
//函数名称: lptmr_clear_registers
//函数返回: 无
//参数说明:
//功能概要: 清上次寄存器的值便于本次设置
//==========================================================================
void lptmr_clear_registers()
{
  LPTMR0_CSR=0x00;
  LPTMR0_PSR=0x00;
  LPTMR0_CMR=0x00;
}