TM4C123GH6PM测高电平时间

LiKent
#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_memmap.h"
#include "inc/hw_ints.h"
#include "driverlib/debug.h"
#include "driverlib/gpio.h"
#include "driverlib/interrupt.h"
#include "driverlib/pin_map.h"
#include "driverlib/timer.h"
#include "driverlib/sysctl.h"
#include "driverlib/uart.h"
#include "driverlib/pwm.h"
#include "utils/uartstdio.h"

 unsigned int interval;
 unsigned int TimerAVal,TimerBVal;
 unsigned int distance;
 unsigned int PFlevel;
 void InitUART(void)
 {
     SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);
     SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
     GPIOPinConfigure(GPIO_PA0_U0RX);
     GPIOPinConfigure(GPIO_PA1_U0TX);
     GPIOPinTypeUART(GPIO_PORTA_BASE,GPIO_PIN_0|GPIO_PIN_1);
     UARTClockSourceSet(UART0_BASE,UART_CLOCK_PIOSC);
     UARTStdioConfig(0,115200,16000000);

 }
void InitPWM()
 {
         SysCtlPWMClockSet(SYSCTL_PWMDIV_1);
         SysCtlPeripheralEnable(SYSCTL_PERIPH_PWM1);//使能pwm1外设
         SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);//使能PF
         GPIOPinConfigure(GPIO_PF1_M1PWM5 );//设置端口复用，
         GPIOPinTypePWM(GPIO_PORTF_BASE, GPIO_PIN_1);//设置端口的pwm输出功能
         PWMGenConfigure(PWM1_BASE, PWM_GEN_2, PWM_GEN_MODE_DOWN | PWM_GEN_MODE_NO_SYNC);//下降计数，非同步
         PWMGenPeriodSet(PWM1_BASE, PWM_GEN_2, 320);//0.05MHz
         PWMPulseWidthSet(PWM1_BASE, PWM_OUT_5, 160);//占空比50%，脉冲宽度
         PWMOutputState(PWM1_BASE, PWM_OUT_5_BIT, true);
         PWMGenEnable(PWM1_BASE, PWM_GEN_2);
                 }
 /*
  * pf1 used to trigger the hc-sr04
  * pb6 used to calculate the time of high level on echo
  *PB7 used to detect rising edge then enter the Interrupt handler in which i enable
  * the timerA(PB6)
  *  */

 void PortB7IntHandler(void)
 {
    GPIOIntClear(GPIO_PORTB_BASE,GPIO_INT_PIN_7);
    TimerLoadSet(TIMER0_BASE,TIMER_A,60000);

     IntEnable(INT_TIMER0A);

     TimerEnable(TIMER0_BASE,TIMER_A);

     //UARTprintf("Enter PB7 interrupt");

 }
 void Timer0AIntHandler(void)
 {
     TimerIntClear(TIMER0_BASE,TIMER_CAPA_EVENT);
     TimerAVal=TimerValueGet(TIMER0_BASE,TIMER_A);
     TimerDisable(TIMER0_BASE,TIMER_A);
     //UARTprintf("enter timerA interrupt");
 }
 void main()
 {
     SysCtlClockSet(SYSCTL_SYSDIV_1|SYSCTL_XTAL_16MHZ|SYSCTL_USE_OSC|SYSCTL_OSC_MAIN);
     InitUART();
    InitPWM();
     UARTprintf("UART configured properly\n");

     SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);
     SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER0);

     GPIOPinTypeGPIOInput(GPIO_PORTB_BASE,GPIO_PIN_7);


//使用PF1产生周期为100us，占空比为50%的方波，触发会hc-sr04。Pb7在echo检测到上升沿进入GPIO中断
     //在中断处理函数里面，开启PB6的定时器，设置为捕获计时模式，捕获下降沿时触发中断，在中断处理函数里读取定时器的值


     GPIOIntTypeSet(GPIO_PORTB_BASE,GPIO_PIN_7,GPIO_RISING_EDGE);//PB7配置为上升沿中断
     GPIOIntEnable(GPIO_PORTB_BASE,GPIO_INT_PIN_7);
     GPIOIntRegister(GPIO_PORTB_BASE,PortB7IntHandler);
     IntEnable(INT_GPIOP7);

     GPIOPinConfigure(GPIO_PB6_T0CCP0);
     GPIOPinTypeTimer(GPIO_PORTB_BASE,GPIO_PIN_6);
     TimerConfigure(TIMER0_BASE,TIMER_CFG_SPLIT_PAIR|TIMER_CFG_A_CAP_TIME);//捕获计时模式


     IntMasterEnable();


     TimerControlEvent(TIMER0_BASE,TIMER_A,TIMER_EVENT_NEG_EDGE);//下降沿触发定时器timer0A中断

     TimerIntEnable(TIMER0_BASE,TIMER_CAPA_EVENT);//定时器捕捉下降沿产生中断


     TimerIntRegister(TIMER0_BASE,TIMER_A,Timer0AIntHandler) ;





     while(1)
     {


     interval=60000-TimerAVal;

     UARTprintf("the interval is%d\n",interval);

     }





 }