PIC单片机进阶实战（一）：PIC16F1947串口通信及不同波特率转换

2026-02-03 22:52:48 栏目：最新资讯 4 阅读

从业三十余年，我从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，PIC16F1947 成为我近年来高频使用的核心芯片。其丰富的外设与双串口设计，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控制板为例，详解其串口架构与双波特率灵活配置的实现方法。

该控制板集成了以下8大功能，覆盖多数物联网与工控场景：

1、6路继电器输出；

2、2路DC24V或12V直流电机正反转控制；

3、1路4G模块数据收发；

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、1路电流互感器（5A/10A）数据采集；

7、1路数模转换（数字量转4-20mA/0-5V/0-10V）;

8、1路模数转换（4-20mA/0-5V/0-10V转数字量）。

一、硬件设计：双串口电路详解

PIC16F1947具备两个独立UART模块，本设计中：

UART1 通过电平转换电路连接4G模块，实现无线远程通信。
UART2 可通过跳线切换为LORA无线或RS485有线通信，增强系统灵活性。

1、电平匹配电路

2、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（16M主频），串口1波特率115200，串口2波特率9600，都是8N1格式，数据双向透传，具体配置及程序如下：

#include

__CONFIG(0x007c); //内部时钟16M

__CONFIG(0x1010); //内部时钟16M

unsigned char dres_485=1,sec_5s=0,half_sec=0 ,flag_rev=0,flag_rev2=0,leijia_tnt2;

unsigned int  time_tnt,time_tnt2,sec_05s,rev_rnt=0,rev_rnt2=0,tran_rnt=0,tran_rnt2=0,sec_1s=0;

unsigned char eeprom_e2[30]; //EEPROM缓存

unsigned long result_3421[30];

unsigned char trans[50];

unsigned char reciv[200]; //串口1接收缓存

unsigned char reciv2[200]; //串口2接收缓存

void delay(unsigned int v)

  while(v!=0)v--;

void uart_send(unsigned char dat) //串口1发送

               TX1STAbits.TXEN=1;

               TX1REG=dat;

               while(!TX1STAbits.TRMT);

void uart_send2(unsigned char datt) //串口2发送

               TX2STAbits.TXEN=1;

               TX2REG=datt;

               while(!TX2STAbits.TRMT);

void interrupt isr(void)

               if(TMR1IF)

                               TMR1L=0xbf;

                               TMR1H=0xf9;

                               sec_05s+=1;

                               sec_1s+=1;

                               if(sec_05s>624) //0.5s

                                              half_sec+=1;

                                              sec_5s+=1;

                                              sec_05s=0;

                               if(flag_rev==1)

                                              time_tnt+=1;  //1570约为06ms

                               if(flag_rev2==1)

                                              time_tnt2+=1;  //1570约为06ms

                               TMR1IF=0;

               if(RCIF)

                               reciv[rev_rnt]=RC1REG;

                               rev_rnt+=1;

                               time_tnt=0;

                               flag_rev=1;

                               RCIF=0;

               if(RC2IF)

                               reciv2[rev_rnt2]=RC2REG;

                               rev_rnt2+=1;

                               time_tnt2=0;

                               flag_rev2=1;

                               RC2IF=0;

void main()

               unsigned int i,j;

               unsigned char tmp;

               ANSELF=0;

               ANSELG=0;

//             ADCON0=0;

               TRISC=0x80;

               TRISB=0x87;

               OPTION_REG&=0X7F;

               WPUB7=1;

               TRISD=0x00;

               TRISE=0x00;

               TRISF=0x00;

               TRISG=0x0c;

//             TRISG=0x00;

               PORTC=0x38;

               PORTD=0x00;

               PORTE=0x00;

               PORTF=0x00;

               PORTG=0x00;

//             OSCCON=0x0;

               OSCSTAT=0xa0;

               OSCCON=0x78; //内部时钟16M

//             OSCCON=0xf0; //32M

//             OSCSTAT=0xf0;//32M

               PIE1=0x21;

               INTCON=0x00;

               T1CON=0x70;

               TMR1IF=0;

               TMR1L=0xbf; //0.8ms

               TMR1H=0xf9;

               TMR1IE=1;

               T1CON=0x71;

//             SYNC=0;                                             //异步模式

//             BRGH=1;                                            //加速

               TX1STA=0x24;  //8 n 1

               RC1STA=0x90;

//             BRG16=1;

               BAUD1CON=0x08;

//             SPEN=1;                                              //允许串行通讯

//             TXEN=1;

//             CREN=1;

               RCIF=0;

               RCIE=1;

//             SP1BRGL=0xa0;  //9600  //16MHZ

//             SP1BRGH=0x01;

               SP1BRGL=0x22;  //115200  //16MHZ

               SP1BRGH=0x00;

               RC2IF=0;

               RC2STA=0x90;  //8 n 1

               TX2STA=0x24;

//             RC2STA=0xd0;  //8 n 2

//             TX2STA=0x64;

//             BRG16=1;

               BAUD2CON=0x08;

               RC2IE=1;

               SP2BRGH=0x01;

               SP2BRGL=0xa0;  //9600 //16MHZ

PEIE=1;

GIE=1;

while(1)

                               asm("clrwdt");

                               if((flag_rev==1)&&(time_tnt>7))  //time_tnt=125约为10ms

            PORTG|=0X0001;

                                              for(i=0;i

                                                                            uart_send2(reciv[i]);

                                              PORTG&=0XFFFE;

                                                             rev_rnt=0;

                                                             time_tnt=0;

                                                             flag_rev=0;

                               if((flag_rev2==1)&&(time_tnt2>5))

                                              for(i=0;i

                                                                            uart_send(reciv2[i]);

                                              rev_rnt2=0;

                                              time_tnt2=0;

                                              flag_rev2=0;

三、本系列文章规划

《PIC单片机进阶实战》系列共六篇，后续将逐步展开以下内容：

序号	主题	内容概要
1	UART通信	双串口配置、波特率转换、数据透传
2	4G模块数据收发	AT指令控制、4G模块数据透传
3	电流互感器数据采集	5A、10A电流采集
4	数模转换	12位模拟量输出4-20mA/0-5V/0-10V
5	输入输出	开关量输入、控制继电器与直流电机
6	模数转换	4-20mA/0-5V/0-10V模拟量采集