等到用户输入值并将其分配给 var

Question

这是一个微不足道的问题，但在过去的几天里它仍然让我驯服。 我试图获取用户输入并等到用户输入值，但我的程序没有这样做。 如果有人可以帮助我，我将不胜感激。

这个想法是程序应该打印用户应该使用键盘输入值的消息并等待输入键盘输入。 并且根据输入，某些端口引脚数据寄存器应设置为高，以便最终调用端口中断处理程序。

/**
* main.c
*/
#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#include "tm4c1294ncpdt.h"
#include "int_handler.h"
#include "inc/hw_memmap.h"

#include "driverlib/sysctl.h"
#include "driverlib/rom.h"
#include "driverlib/gpio.h"
#include "driverlib/pin_map.h"
#include "driverlib/rom_map.h"
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"

//states[3]=[0,0,0]; //S0,S1,Error
/**
 * main.c
 * 2 out 3,3V
 * 2 in 3,3V
 */
int main(void)
{
    // Port Clock Gating Control Port A
    SYSCTL_RCGCGPIO_R |= 0x00000001;
    while((SYSCTL_PRGPIO_R & 0x00000001) == 0);
    // Set INPUT direction I/O pin PA6
    GPIO_PORTA_AHB_DIR_R &= 0xBF;
    // Digital I/O pins PA6 enable
    GPIO_PORTA_AHB_DEN_R |= 0x40;
    GPIO_PORTA_AHB_DATA_R &= 0x00;
    //GPIO_PORTA_AHB_AFSEL_R &= ~0x40; // disable alt funct on PA6 (default setting)

    //GPIO_PORTA_AHB_PCTL_R &= ~0x0F000000;// configure PA6 as GPIO (default setting)
    //GPIO_PORTA_AHB_AMSEL_R &= ~0x40;// disable analog functionality on PA6 (default setting)
    GPIO_PORTA_AHB_IS_R &= ~0x40;   // PA6 is edge-sensitive (default setting)
    GPIO_PORTA_AHB_IBE_R &= ~0x40;  // PA6 is not both edges (default setting)
    GPIO_PORTA_AHB_IEV_R |= 0x40;   // PA6 rising edge event
    GPIO_PORTA_AHB_ICR_R = 0x40;    // clear flag6
    GPIO_PORTA_AHB_IM_R |= 0x40;    // enable interrupt on PA6
                                // GPIO PortC=priority 2
    NVIC_EN0_R |= (1<<0); // enable PortA interrupt (Int#0/Vec#16) in NVIC


    // Port Clock Gating Control Port B
    SYSCTL_RCGCGPIO_R |= 0x00000002;
    while((SYSCTL_PRGPIO_R & 0x00000002) == 0);
    // Set output direction I/O pins PB0 to PB7
    GPIO_PORTB_AHB_DIR_R |= 0xFF;
    // Digital I/O pins PB2 to PB3 enable
    GPIO_PORTB_AHB_DEN_R |= 0x0C;

    // Port Clock Gating Control Port C
    SYSCTL_RCGCGPIO_R |= 0x00000004;
    while((SYSCTL_PRGPIO_R & 0x00000004) == 0);
    // Set output direction I/O pins PC0 to PC7
    GPIO_PORTC_AHB_DIR_R |= 0xFF;
    // Digital I/O pins PC4 to PC7 enable
    GPIO_PORTC_AHB_DEN_R |= 0xF0;


    // Port Clock Gating Control Port D
    SYSCTL_RCGCGPIO_R |= 0x00000008;
    while((SYSCTL_PRGPIO_R & 0x00000008) == 0);
    // Set output direction I/O pins PD3
    GPIO_PORTD_AHB_DIR_R |= 0x0F;
    GPIO_PORTD_AHB_DIR_R &= 0x0F;     // Set INPUT direction I/O pins PD7
    // Digital I/O pins PD3 AND PD7 enable
    GPIO_PORTD_AHB_DEN_R |= 0x88;

    GPIO_PORTD_AHB_IS_R &= ~0x80;   // PD7 is edge-sensitive (default setting)
    GPIO_PORTD_AHB_IBE_R &= ~0x80;  // PD7 is not both edges (default setting)
    GPIO_PORTD_AHB_IEV_R |= 0x80;   // PD7 rising edge event
    GPIO_PORTD_AHB_ICR_R = 0x80;    // clear flag6
    GPIO_PORTD_AHB_IM_R |= 0x80;    // enable interrupt on PA6

    NVIC_EN0_R |= (1<<3); // enable PortD interrupt (Int#3/Vec#19) in NVIC



    // Port Clock Gating Control Port E
    SYSCTL_RCGCGPIO_R |= (1 << 4);
    while((SYSCTL_PRGPIO_R & (1 << 4)) == 0);
    // Set INPUT direction I/O pins PE0 to PE3
    GPIO_PORTE_AHB_DIR_R &= 0xF0;
    GPIO_PORTE_AHB_DIR_R |= 0xF0;// Set OUTPUT direction I/O pins PE5
    // Digital I/O pins PE0 to PE3 AND PE5 enable
    GPIO_PORTE_AHB_DEN_R |= 0x2F;

    GPIO_PORTE_AHB_IS_R &= ~0x0F;   // PE0 to PE3 is edge-sensitive (default setting)
    GPIO_PORTE_AHB_IBE_R &= ~0x0F;  // PA6 is not both edges (default setting)
    GPIO_PORTE_AHB_IEV_R |= 0x0F;   // PA6 rising edge event
    GPIO_PORTE_AHB_ICR_R = 0x0F;    // clear flag6
    GPIO_PORTE_AHB_IM_R |= 0x0F;    // enable interrupt on PA6
                                // GPIO PortC=priority 2
    NVIC_EN0_R |= (1<<4); // enable PortE interrupt (Int#4/Vec#20) in NVIC


    // Port Clock Gating Control Port M
    SYSCTL_RCGCGPIO_R |= (1 << 11);
    while((SYSCTL_PRGPIO_R & (1 << 11)) == 0);
    // Set input direction I/O pins PM4 and PM5
    GPIO_PORTM_DIR_R &= ~(0x30);
    // Digital I/O pins PM4 and PM5 enable
    GPIO_PORTM_DEN_R |= 0x30;

    GPIO_PORTM_IS_R &= ~0x30;   // PE0 to PE3 is edge-sensitive (default setting)
    GPIO_PORTM_IBE_R &= ~0x30;  // PA6 is not both edges (default setting)
    GPIO_PORTM_IEV_R |= 0x30;   // PA6 rising edge event
    GPIO_PORTM_ICR_R = 0x30;    // clear flag6
    GPIO_PORTM_IM_R |= 0x30;    // enable interrupt on PA6
                                  // GPIO PortC=priority 2
    NVIC_EN2_R |= (1<<8); // enable PortM interrupt (Int#72/Vec#88) in NVIC

    while(1){
        //DEMO
        //Placing instructions with keyboard
        int i;
        char name='m';
        //fflush(stdout);
        printf("Please enter l or r");
        fflush(stdout);


        //gets(name);
        //scanf(" %c", &name);
        //fgets(name,5,stdin);
        //getchar();

        while(name != 'l' && name != 'r'){
            scanf("%c", &name);
        }

        printf("U entered %c", name);
        fflush(stdout);
        if(name=='l')//PE0 is high
        {
            GPIO_PORTE_AHB_DATA_R |= 0x01; // PE0 high
            for(i=0;i<500000;i++);
            GPIO_PORTE_AHB_DATA_R &= 0x00; // PE0 LOW
        }
        else if(name=='r'){
            GPIO_PORTE_AHB_DATA_R |= 0x02; // PE1 high
            for(i=0;i<500000;i++);
            GPIO_PORTE_AHB_DATA_R &= 0x00; // PE1 LOW
        }
        else{
            printf("Pls enter l or r");
            fflush (stdout);

        }

    }
}

Answer 1

由于name是char ，您不应该与strcmp进行比较。

用

while(name != 'l' && name != 'r'){
    scanf("%c", &name);
}
//name cannot have values other than 'l' and 'r' here

//...

if(name == 'l'){
//...
}else{
//...
}