作为一名使用PIC单片机近三十年的工程师，我最早从PIC16F87X系列起步，逐步深入至更集成、功能更丰富的型号。在智慧农业、工业控制等实际项目中，PIC32MX是我频繁使用的核心芯片。其丰富的外设与六串口设计，非常适合构建多通道通信与控制系统。本次我将以一款实际投产数年的核心控制板为例，控制板MCU型号为PIC32MX534F064H，详解其六串口架构与不同波特率灵活配置的实现方法。

该控制板集成了以下6大功能：

1、2路RS485数据收发(可接LED屏、各种传感器、或与其他控制板通信)；

2、1路UART-TTL（可接摄像头等）；

3、1路4G模块数据收发（移远或中移4G模块）；

4、1路LORA无线数据收发或RS485数据收发；

5、2路无源开关量输入；

6、太阳能供电（带充电管理）或直流电源直接供电；

一、硬件设计：串口电路详解

PIC32MX534F064H具备六个独立UART模块，本设计中：

  • UART1 可通过跳线切换为LORA无线或RS485有线通信，增强系统灵活性。
  • UART2 通过电平转换电路连接4G模块，实现无线远程通信。
  • UART3、UART6为RS485有线通信，可接LED屏、触摸屏、各种传感器等。
  • UART4 为UART-TTL，可接摄像头等。
  • UART5 在本控制板上没有使用。

UART1、UART2可以设置为中断接收数据，UART3- UART6只能是查询接收数据。

RS485接口电路

二、串口例程：

PIC单片机输入输出寄存器的控制字设置与其他如MSP430系列单片机不一样，一般其他系列单片机某一I/O口输出置1、输入置0；PIC则相反，输出置0、输入置1，你可以把0想成O（对应OUT），把1想成I（对应IN），这样会不容易设置错。

以下是串口示例（80M主频），串口1波特率9600，串口2波特率115200，串口3、4、6波特率都是9600，都是8N1格式，数据在不同串口间可透传，具体配置及程序如下：

#include<p32mx534f064h.h>

#pragma config FPLLMUL=MUL_20,FPLLIDIV=DIV_2,FPLLODIV=DIV_1,FWDTEN=OFF
#pragma config POSCMOD=HS,FNOSC=PRIPLL,FPBDIV=DIV_1


#define SYS_FREQ                          (80000000L)


unsigned char dres_485=1, flag_rev=0,flag_rev2=0,flag_rev3,flag_rev4,flag_rev5,flag_rev6;


unsigned int  time_tnt,time_tnt2,time_tnt3,time_tnt4,time_tnt5,time_tnt6, ,rev_rnt=0,rev_rnt2=0,rev_rnt3,rev_rnt4,rev_rnt5,rev_rnt6,tran_rnt1=0,tran_rnt2=0,tran_rnt3,tran_rnt4,tran_rnt5,tran_rnt6;




unsigned char trans[200];


unsigned char reciv[200];


unsigned char trans2[200];


unsigned char reciv2[200];


unsigned char trans3[200];


unsigned char reciv3[200];


unsigned char trans4[200];


unsigned char reciv4[200];


unsigned char trans5[200];


unsigned char reciv5[200];


unsigned char trans6[200];


unsigned char reciv6[200];


void delay(unsigned int a)


               {


               int i,j;


               for(i=0;i<a;i++)


                               for(j=0;j<100;j++)


                                              ;


               }


void uart_send1(unsigned char dat) //串口1发送数据


{


               U1STAbits.UTXEN=1;


               U1TXREG=dat;


               while(!U1STAbits.TRMT);


}


void uart_send2(unsigned char dat) //串口2发送数据


{


               U2STAbits.UTXEN=1;


               U2TXREG=dat;


               while(!U2STAbits.TRMT);


}


void uart_send3(unsigned char dat)


{


               U3STAbits.UTXEN=1;


               U3TXREG=dat;


               while(!U3STAbits.TRMT);


}


void uart_send4(unsigned char dat)


{


               U4STAbits.UTXEN=1;


               U4TXREG=dat;


               while(!U4STAbits.TRMT);


}


void uart_send5(unsigned char dat)


{


               U5STAbits.UTXEN=1;


               U5TXREG=dat;


               while(!U5STAbits.TRMT);


}


void uart_send6(unsigned char dat)


{


               U6STAbits.UTXEN=1;


               U6TXREG=dat;


               while(!U6STAbits.TRMT);


}


void main() {


    unsigned int i,j; 


                               AD1PCFG=0XFFFF;


                               


                               TRISB=0x0180;


               


                               PORTB=0x0000;


                               TRISC=0;


                               PORTC=0x0000;


                               TRISD=0x0204;


                               PORTD=0x0000;


                               TRISE=0x0000;


                               PORTE=0x0000;


                               TRISF=0x0010;


                               PORTF=0x0000;


                               TRISG=0x0280;


                               PORTG=0x0000;


                               DDPCON = 0x00 ;  //关闭EJTAG口，


                               OSCCON&=0xfffd;


SYSTEMConfig(SYS_FREQ, SYS_CFG_WAIT_STATES | SYS_CFG_PCACHE);


ConfigIntTimer1(T1_INT_ON | T1_INT_PRIOR_5 | T1_INT_SUB_PRIOR_1);


INTConfigureSystem(INT_SYSTEM_CONFIG_MULT_VECTOR);


UARTSetLineControl(UART1, UART_DATA_SIZE_8_BITS | UART_PARITY_NONE | UART_STOP_BITS_1);


                           UARTConfigure(UART1, UART_ENABLE_HIGH_SPEED|UART_ENABLE_PINS_TX_RX_ONLY);


                           UARTSetDataRate(UART1, SYS_FREQ,9600);


                           UARTSetFifoMode(UART1, UART_INTERRUPT_ON_RX_NOT_EMPTY);




                           ConfigIntUART1(UART_RX_INT_EN | UART_INT_PR6 | UART_INT_SUB_PR2);


                           EnableIntU1RX;


                           UARTEnable(UART1, UART_ENABLE_FLAGS(UART_PERIPHERAL | UART_RX | UART_TX));




                           UARTSetLineControl(UART2, UART_DATA_SIZE_8_BITS | UART_PARITY_NONE | UART_STOP_BITS_1);


                           UARTConfigure(UART2, UART_ENABLE_HIGH_SPEED|UART_ENABLE_PINS_TX_RX_ONLY);


                           UARTSetDataRate(UART2, SYS_FREQ, 115200);


                           UARTSetFifoMode(UART2, UART_INTERRUPT_ON_RX_NOT_EMPTY);




                           ConfigIntUART2(UART_RX_INT_EN | UART_INT_PR6 | UART_INT_SUB_PR2);


                           EnableIntU2RX;


                           UARTEnable(UART2, UART_ENABLE_FLAGS(UART_PERIPHERAL | UART_RX | UART_TX));




                           UARTSetLineControl(UART3, UART_DATA_SIZE_8_BITS | UART_PARITY_NONE | UART_STOP_BITS_1);


                           UARTConfigure(UART3, UART_ENABLE_HIGH_SPEED|UART_ENABLE_PINS_TX_RX_ONLY);


                           UARTSetDataRate(UART3, SYS_FREQ, 9600);


                           UARTSetFifoMode(UART3, UART_INTERRUPT_ON_RX_NOT_EMPTY);




                           UARTEnable(UART3, UART_ENABLE_FLAGS(UART_PERIPHERAL | UART_RX | UART_TX));




                           UARTSetLineControl(UART4, UART_DATA_SIZE_8_BITS | UART_PARITY_NONE | UART_STOP_BITS_1);


                           UARTConfigure(UART4, UART_ENABLE_HIGH_SPEED|UART_ENABLE_PINS_TX_RX_ONLY);


                           UARTSetDataRate(UART4, SYS_FREQ, 9600);


                           UARTSetFifoMode(UART4, UART_INTERRUPT_ON_RX_NOT_EMPTY);




                           UARTEnable(UART4, UART_ENABLE_FLAGS(UART_PERIPHERAL | UART_RX | UART_TX));




                           UARTSetLineControl(UART5, UART_DATA_SIZE_8_BITS | UART_PARITY_NONE | UART_STOP_BITS_1);


                           UARTConfigure(UART5, UART_ENABLE_HIGH_SPEED|UART_ENABLE_PINS_TX_RX_ONLY);


                           UARTSetDataRate(UART5, SYS_FREQ, 115200);


                           UARTSetFifoMode(UART5, UART_INTERRUPT_ON_RX_NOT_EMPTY);




                           UARTEnable(UART5, UART_ENABLE_FLAGS(UART_PERIPHERAL | UART_RX | UART_TX));




                           UARTSetLineControl(UART6, UART_DATA_SIZE_8_BITS | UART_PARITY_NONE | UART_STOP_BITS_1);


                           UARTConfigure(UART6, UART_ENABLE_HIGH_SPEED|UART_ENABLE_PINS_TX_RX_ONLY);


                           UARTSetDataRate(UART6, SYS_FREQ, 9600);


                           UARTSetFifoMode(UART6, UART_INTERRUPT_ON_RX_NOT_EMPTY);




                           UARTEnable(UART6, UART_ENABLE_FLAGS(UART_PERIPHERAL | UART_RX | UART_TX));


//其他初始化


INTEnableInterrupts();


                           OpenTimer1(T1_ON | T1_PS_1_1 | T1_SOURCE_INT,4000); //分频设置为1


delay(10000);


while(1) {


if(U3STAbits.URXDA)


                                          {


                                                         reciv3[rev_rnt3]=UARTGetDataByte(UART3);


                                                         


                                                         rev_rnt3+=1;


                                                         time_tnt3=0;


                                                         flag_rev3=1;


                                          } 


                                          if(U4STAbits.URXDA)


                                          {


                                                         reciv4[rev_rnt4]=UARTGetDataByte(UART4);


                                                         


                                                         rev_rnt4+=1;


                                                         time_tnt4=0;


                                                         flag_rev4=1;


                                          } 


                                          if(U5STAbits.URXDA)


                                          {


                                                         reciv5[rev_rnt5]=tmp3=UARTGetDataByte(UART5);


                                                         


                                                         rev_rnt5+=1;


                                                         time_tnt5=0;


                                                         flag_rev5=1;


                                          }


                                          if(U6STAbits.URXDA)


                                          {


                                                         reciv6[rev_rnt6]=UARTGetDataByte(UART6);


                                                         


                                                         rev_rnt6+=1;


                                                         time_tnt6=0;


                                                         flag_rev6=1;


                                          }


        // 主循环，可加入其他任务


    }


}




void __ISR(_UART1_VECTOR, IPL6SOFT) IntUart1Handler(void)


{


  


  if (INTGetFlag(INT_SOURCE_UART_RX(UART1)))


    {


      


             reciv[rev_rnt]=UARTGetDataByte(UART1);


              


              


                     rev_rnt+=1;


                     time_tnt=0;


                     flag_rev=1;


              


                            




    }  


      INTClearFlag(INT_SOURCE_UART_RX(UART1));




      


}


void __ISR(_UART2_VECTOR, IPL6SOFT) IntUart2Handler(void)


{


  


  if (INTGetFlag(INT_SOURCE_UART_RX(UART2)))


    {


      


              reciv2[rev_rnt2]=tmp2=UARTGetDataByte(UART2);


              


                            rev_rnt2+=1;


                            time_tnt2=0;


                            flag_rev2=1;




    }  


      INTClearFlag(INT_SOURCE_UART_RX(UART2));




      


}




void __ISR(_TIMER_1_VECTOR, ipl5) _Timer1Handler(void)




{




 //      DisableIntT1;


              


              if(flag_rev==1)


              {


                     time_tnt+=1;  //1570约为06ms


              }


              if(flag_rev2==1)


              {


                     time_tnt2+=1;  //1570约为06ms


              } 


              if(flag_rev3==1)


              {


                     time_tnt3+=1;  //1570约为06ms


              } 


              if(flag_rev4==1)


              {


                     time_tnt4+=1;  //1570约为06ms


              } 


              if(flag_rev5==1)


              {


                     time_tnt5+=1;  //1570约为06ms


              } 


              if(flag_rev6==1)


              {


                     time_tnt6+=1;  //1570约为06ms


              } 


              


              INTClearFlag(INT_T1);//中断标志清零


 




//       EnableIntT1;




}三、本系列文章规划


本文是《PIC单片机高阶实战》系列的第一篇，后续将逐步展开以下内容：



 
  

   
    
序号

   
    
主题

   
    
内容概要

  

  

   
    
1

   
    
振荡器与定时器

   
    
时钟配置与定时中断

  

  

   
    
2

   
    
UART通信

   
    
串口配置、波特率转换、数据透传

  

  

   
    
3

   
    
I/O按键输入

   
    
电平变化中断

  

  

   
    
4

   
    
4G模块数据收发

   
    
AT指令控制、4G模块数据透传

  

  

   
    
5

   
    
数据存储

   
    
数据存储与读取

  

 



《PIC单片机入门实战》共8篇文章与《PIC单片机进阶实战》共6篇文章与《PIC单片机高阶实战》5篇内容来源于我自己画的电路原理图及程序，有对PIC单片机感兴趣想学习的朋友可以关注我，免费赠送资料（包括原理图、数据手册、各种例程等）。


有需要这款开发板的朋友也可以关注联系我。




后续干货不断，咱们一起在单片机的世界里，共同进步。


 
  

        # 单片机
      
        # 嵌入式硬件
      
        # 物联网
      
  
 
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