按下按钮后,我无法打破if语句。该按钮激活继电器,按下该按钮可关闭继电器。
这是我的完整代码:我是C语言的新手,因此非常感谢所有注释和建议。
#include "mcc_generated_files/mcc.h"
#define FCY 8000000UL
#include <libpic30.h>
//#define baudrate 19200
int main(void)
{
// Initialise the device
SYSTEM_Initialize();
while(1)
{
LED4_SetLow(); // Turn on 3v3 LED
LED12v_SetHigh();
LED3_SetHigh();
LED1_SetHigh();
int button;
button = UART5_Read();
if (button == 0x08)
{
RLY1_SetHigh();
RLY3_SetHigh();
if (button == 0x00)
goto finished;
}
finished:
RLY1_SetLow();
RLY3_SetLow();
}
return (0);
}
我现在按如下方式编辑了代码。可以将继电器设置为高电平,但永远不会达到条件0x00。有人可以解释吗?
#include "mcc_generated_files/mcc.h"
#define FCY 8000000UL
#include <libpic30.h>
//#define baudrate 19200
int main(void)
{
// Initialise the device
SYSTEM_Initialize();
while(1)
{
LED4_SetLow(); // Turn on 3v3 LED
LED12v_SetHigh();
LED3_SetHigh();
LED1_SetHigh();
int button;
int release;
button = UART5_Read();
release = UART5_Read();
if (button == 0x08)
{
RLY1_SetHigh();
RLY3_SetHigh();
}
if (release == 0x00)
{
RLY1_SetLow();
RLY3_SetLow();
}
__delay_ms(1000);
}
return (0);
}
我没有使用过此MCU或其库,但我认为正确的代码应与此类似:
#include "mcc_generated_files/mcc.h"
#include <libpic30.h>
#include <stdint.h>
#define BUTTON_CODE 0x8u // use named constants instead of magic numbers
void main (void)
{
// Initialise the device
SYSTEM_Initialize();
for(;;)
{
uint8_t data;
LED4_SetLow(); // Turn on 3v3 LED
LED12v_SetHigh();
LED3_SetHigh();
LED1_SetHigh();
if(UART5_Data_Ready())
{
data = UART5_Read();
if(data == BUTTON_CODE)
{
RLY1_SetHigh();
RLY3_SetHigh();
}
else
{
RLY1_SetLow();
RLY3_SetLow();
}
}
}
}