LPC1769 UART通信问题

2019-07-15 17:08发布

真的是超级新手，完全小白，希望能有大师指点一下，非常感谢！
我的任务是用串口助手从PC向单片机通过UART0发送一个信号，然后再用UART3将这个信号传递给外部连接的电池（中间通过RS485收发器转换电平，P2.12是作为RS485收发器的Enable引脚）。电池收到信号后，通过UART3返回信号到单片机，再经过UART0返回到电脑显示在串口助手上。

现在发送和接受都有问题，但是我真的太新手，完全不知道该从哪里下手解决问题。
我觉得UART的初始化和timer的初始化应该是没有问题的，主要问题应该在UART0_IRQHander和UART3_IRQHander里，希望各位前辈能提提意见，不胜感谢！

#ifdef __USE_CMSIS
#include "LPC17xx.h"
#endif

#include "stdutils.h"

#define SBIT_WordLenght 0x00u
#define SBIT_DLAB       0x07u
#define SBIT_FIFO       0x00u
#define SBIT_RxFIFO       0x01u
#define SBIT_TxFIFO       0x02u

#define SBIT_RDR          0x00u
#define SBIT_THRE       0x05u

uint8_t Uart0RecvBuf;
uint8_t Uart3RecvBuf;

#define SBIT_TIMER0  1
#define SBIT_TIMER1  2

#define SBIT_MR0I 0
#define SBIT_MR0R 1

#define SBIT_CNTEN 0

#define PCLK_TIMER0  2
#define PCLK_TIMER1  4
#define MiliToMicroSec(x)  (x)  // ms is multiplied by 1000 to get us

extern unsigned int SystemCoreClock;
unsigned int getPrescalarForUs0(uint8_t timerPclkBit);

// Function to initialize the UART0 and UART3 at specific baud rate
void uart_init(uint32_t baudrate)
{
uint32_t var_UartPclk_u32_0,var_Pclk_u32_0,var_RegValue_u32_0;
uint32_t var_UartPclk_u32_3,var_Pclk_u32_3,var_RegValue_u32_3;

LPC_SC->PCONP |= (1<<3)|(1<<25);    //enable UART0,UART3 power/clock control bit

LPC_PINCON->PINSEL0 &= ~0x000000FF;
LPC_PINCON->PINSEL0 |= 0x0000005A;          // Enable TxD3 P0.0 and P0.1,TxD0 P0.2 and p0.3

LPC_UART0->FCR = (1<<SBIT_FIFO) | (1<<SBIT_RxFIFO) | (1<<SBIT_TxFIFO); // Enable FIFO and reset Rx/Tx FIFO buffers
LPC_UART0->LCR = (0x03<<SBIT_WordLenght) | (1<<SBIT_DLAB);          // 8bit data, 1Stop bit, No parity
LPC_UART3->FCR = (1<<SBIT_FIFO) | (1<<SBIT_RxFIFO) | (1<<SBIT_TxFIFO); // Enable FIFO and reset Rx/Tx FIFO buffers
LPC_UART3->LCR = (0x03<<SBIT_WordLenght) | (1<<SBIT_DLAB);          // 8bit data, 1Stop bit, No parity

var_UartPclk_u32_0 = (LPC_SC->PCLKSEL0 >> 6) & 0x03;
var_UartPclk_u32_3 = (LPC_SC->PCLKSEL1 >> 18) & 0x03;

switch( var_UartPclk_u32_0 )
{
case 0x00:
      var_Pclk_u32_0 = SystemCoreClock/4;
      break;
case 0x01:
      var_Pclk_u32_0 = SystemCoreClock;
      break;
case 0x02:
      var_Pclk_u32_0 = SystemCoreClock/2;
      break;
case 0x03:
      var_Pclk_u32_0 = SystemCoreClock/8;
      break;
}
var_RegValue_u32_0 = ( var_Pclk_u32_0 / (16 * baudrate ));
LPC_UART0->DLL =  var_RegValue_u32_0 & 0xFF;
LPC_UART0->DLM = (var_RegValue_u32_0 >> 0x08) & 0xFF;

switch( var_UartPclk_u32_3 )
{
case 0x00:
      var_Pclk_u32_3 = SystemCoreClock/4;
      break;
case 0x01:
      var_Pclk_u32_3 = SystemCoreClock;
      break;
case 0x02:
      var_Pclk_u32_3 = SystemCoreClock/2;
      break;
case 0x03:
      var_Pclk_u32_3 = SystemCoreClock/8;
      break;
}
var_RegValue_u32_3 = ( var_Pclk_u32_3 / (16 * baudrate ));
LPC_UART3->DLL =  var_RegValue_u32_3 & 0xFF;
LPC_UART3->DLM = (var_RegValue_u32_3 >> 0x08) & 0xFF;

util_BitClear(LPC_UART0->LCR,(SBIT_DLAB));  // Clear DLAB after setting DLL,DLM
util_BitClear(LPC_UART3->LCR,(SBIT_DLAB));

LPC_UART0->IER = 0x01;       //enable RDA interrupt
LPC_UART3->IER = 0x01;

NVIC_EnableIRQ(UART0_IRQn);
NVIC_EnableIRQ(UART3_IRQn);
}

unsigned int getPrescalarForUs0(uint8_t timerPclkBit)
{
unsigned int pclk,prescalarForUs;
pclk = (LPC_SC->PCLKSEL0 >> timerPclkBit) & 0x03;  /* get the pclk info for required timer */

switch ( pclk )                                  /* Decode the bits to determine the pclk*/
{
case 0x00:
      pclk = SystemCoreClock/4;
      break;

case 0x01:
      pclk = SystemCoreClock;
      break;

case 0x02:
      pclk = SystemCoreClock/2;
      break;

case 0x03:
      pclk = SystemCoreClock/8;
      break;

default:
      pclk = SystemCoreClock/4;
      break;
}

prescalarForUs =pclk/1000000;                   /* Prescalar for 1us (1000000Counts/sec) */

return prescalarForUs;
}

//Initialize P2.12 as RS485-Transceiver Enable
void Pin_Init(void)
{
      LPC_PINCON->PINSEL4 &= (~(1<<24)&(1<<25));  //set p2.12 as GPIO
      LPC_GPIO2->FIODIR |= (1<<12);       //set P2.12 as output
}

//Data send from PC to Battery
//UART0 Receive (from PC)
uint8_t uart0_Receive()
{
      while(util_IsBitCleared(LPC_UART0->LSR,SBIT_RDR));  // Wait till the data is received
      return(LPC_UART0->RBR);                            // Read received data
}
void uart3_Transmit(uint8_t ch)
{
while(util_IsBitCleared(LPC_UART3->LSR,SBIT_THRE)); // Wait for Previous transmission
LPC_UART3->THR=ch;                               // Load the data to be transmitted
}

//Data receive from Battery to PC
//UART3 Receive (from Battery)
uint8_t uart3_Receive()
{
      while(util_IsBitCleared(LPC_UART3->LSR,SBIT_RDR));  // Wait till the data is received
      return(LPC_UART3->RBR);                            // Read received data
}
void uart0_Transmit(uint8_t ch)
{
while(util_IsBitCleared(LPC_UART0->LSR,SBIT_THRE)); // Wait for Previous transmission
LPC_UART0->THR=ch;                               // Load the data to be transmitted
}

//PC interface receive:
void UART0_IRQHandler(void)
{
      NVIC_EnableIRQ(TIMER0_IRQn);                         // Enable Timer0
      //NVIC_DisableIRQ(UART0_IRQn);                         // Disable UART0_Interrupt

      if(((LPC_UART0->IIR>>1) & 0x07) == 0x02)
      {
            LPC_UART0->IER = 0x00;
            LPC_GPIO2->FIOSET |= (1<<12);                      // Set P2.12 to high
            Uart0RecvBuf = uart0_Receive();                      // UART0 Receive
            LPC_UART0->IER = 0x01;                               // Enable RDA Interrupt
            uart3_Transmit(Uart0RecvBuf);                      // UART3 Transmit
      }
}

void UART3_IRQHandler(void)
{
      NVIC_EnableIRQ(TIMER1_IRQn);                         // Enable Timer1
      //NVIC_DisableIRQ(UART3_IRQn);                         // Disable UART3_Interrupt

      if(((LPC_UART3->IIR>>1) & 0x03) == 0x02)
      {
            LPC_UART3->IER = 0x00;
            LPC_GPIO2->FIOCLR |= (1<<12);                      // Set P2.12 to low
            Uart3RecvBuf = uart3_Receive();                      // UART0 Receive
            LPC_UART3->IER = 0x01;                               // Enable RDA Interrupt
            uart0_Transmit(Uart3RecvBuf);                      // UART0 Transmit
      }
}

//Initialize timer
void Timer_Init()
{
      LPC_SC->PCONP |= (1<<SBIT_TIMER0)|(1<<SBIT_TIMER1) ; // Power ON Timer0,1

LPC_TIM0->MCR  = (1<<SBIT_MR0I) | (1<<SBIT_MR0R);    // Clear TC on MR0 match and Generate Interrupt
LPC_TIM0->PR = getPrescalarForUs0(PCLK_TIMER0);    // Prescalar for 1us */
LPC_TIM0->MR0  = MiliToMicroSec(100);                // Load timer value to generate 100us delay
LPC_TIM0->TCR  = (1 <<SBIT_CNTEN);                   // Start timer by setting the Counter Enable

LPC_TIM1->MCR  = (1<<SBIT_MR0I) | (1<<SBIT_MR0R);    /* Clear TC on MR0 match and Generate Interrupt*/
LPC_TIM1->PR = getPrescalarForUs0(PCLK_TIMER1);    /* Prescalar for 1us */
LPC_TIM1->MR0  = MiliToMicroSec(100);                /* Load timer value to generate 500ms delay*/
LPC_TIM1->TCR  = (1 <<SBIT_CNTEN);                   /* Start timer by setting the Counter Enable*/
}

void TIMER0_IRQHandler(void)
{
unsigned int isrMask;
NVIC_DisableIRQ(TIMER0_IRQn); // Disable Timer0

isrMask = LPC_TIM0->IR;
LPC_TIM0->IR = isrMask;       // Clear the Interrupt Bit

LPC_GPIO2->FIOCLR |= (1<<12); // Reset P2.12
}
void TIMER1_IRQHandler(void)
{
unsigned int isrMask;
NVIC_DisableIRQ(TIMER1_IRQn); // Disable Timer1

isrMask = LPC_TIM1->IR;
LPC_TIM1->IR = isrMask;       // Clear the Interrupt Bit

LPC_GPIO2->FIOSET |= (1<<12); // Reset P2.12
}

int main()
{
SystemInit();
Pin_Init();
uart_init(115200);  // Initialize the UART0 and UART3
Timer_Init();

while(1)
{

}
}

友情提示: 此问题已得到解决，问题已经关闭,关闭后问题禁止继续编辑，回答。