在用STC89C52单片机做一个温度采集功能。
功能是这样的:
1、工作频率 11.0592
2、P2.0,P2.1,P2.2,P2.3 普通IO口分别接了四个S18B20温度传感器,用来采集温度。
3、RX,TX分别和电脑的串口连好,实现和电脑通讯
4、电脑串口定时发送定义好的查询帧,单片机串口收到后,判断帧的内容,查询温度,并返回温度数据。
5、功能己经实现,这样运行的也没有问题。
现在的操作方式是被动操作,(也就是电脑发送一帧数据,单片机查询一次温度,并返回)流程如下:
1,电脑串口发送定义好的16字数据 --->2、单片机串口收到数据,根据数据的类型,查询S18B20温度传感器温度---->3,单片机将温度数据再编码成16个字节数据发送给电脑串口---->4,电脑串口收到数据后处理并显示
存在一个问题是:
现在我想在单片机上装一个显示屏,让单片机定时不断查询温度并显示在屏幕上。
但是单片机在进行S18B20查询温度是很讲究时序的,在1602显示屏上显示文字,也是讲究时序的。
问题:单片机正在对S18B20查询温度时(IO口电平拉高,或拉底),这时有串口数据来到,会中断当前的操作,直到中断函数执行完毕。这时查询S18B20的操作时序就不准确了,1602显示屏也一样。
问:有串口数据来到要接收,不能丢弃。对S18B20操作到一半时,也不能中断,不然时序可能不准确。这样怎么处理?有什么两全其美的方法吗?
电路图:
单片机源码
- #include "config.h"
- #include<ds1.h>
- #include<ds2.h>
- #include<ds3.h>
- #include<ds4.h>
- void UART_init();
- void PutFrame(uchar *TXStr);
- void DataFrame_Put_init();
- void TEMP_init_var();
- uchar dataFrame[16]; //定义数据帧长度为16个字节
- uchar dataFrame_RI; //数据帧是否己读取标记
- uchar dataFrame_temp[16]; //数据帧临时缓冲区16个字节
- uchar dataFrame_temp_count; //定义数据帧己接收的字节数
- //定义发送数据缓冲区
- uchar DataFrame_Put[16]={DATAFRAME_HEAD,DEVICEID_1,DEVICEID_2,0,0,0,0,0,0,0,0,0,0,0,0,DATAFRAME_TAIL};
- INT32U led1_count; //运行指示灯倒计时变量
- uchar led1_count2; //运行指示灯倒计时变量2
- INT32U led2_count; //收到心跳倒计时变量
- INT32U led3_count; //有数据接收倒计时变量
- INT32U led4_count; //有数据发送倒计时变量
- #define LED1_COUNT 15000
- #define LED2_COUNT 125000
- #define LED3_COUNT 100
- #define LED4_COUNT 100
- //存储温度的高8位和底8位
- uchar ds_M;
- uchar ds_L;
- //温度变量
- uchar symbol; //符号位
- uchar hundreds; //百位
- uchar decade; //十位
- uchar unit; //个位
- uchar decimal; //小数1位
- void main()
- {
- //串口初始化
- UART_init();
- while(1)
- {
- //调试使用
- //uchar dataFrame[16] = {DATAFRAME_HEAD,DEVICEID_1,DEVICEID_2,0,0,1,1,0,0,0,0,0,0,0,0,DATAFRAME_TAIL};
- //dataFrame_RI = 1; //执行时间2.17微妙
- //如果己接收到一帧数据
- if(dataFrame_RI == 1) // 执行时间5.42微秒
- {
- //收到心跳
- if(dataFrame[3] == 0 && dataFrame[4] == 0 && dataFrame[5] == 0 && dataFrame[6] == 1){
- //收到心跳
- DataFrame_Put[3] = 0;
- DataFrame_Put[4] = 0;
- DataFrame_Put[5] = 0;
- DataFrame_Put[6] = 1;
- PutFrame(&DataFrame_Put);
- led2_count = LED2_COUNT;
- }else if(dataFrame[3] == 0 && dataFrame[4] == 0 && dataFrame[5] == 0 && dataFrame[6] == 2){
- //收到查询设备id
- DataFrame_Put[3] = 1;
- DataFrame_Put[4] = 0;
- DataFrame_Put[5] = 0;
- DataFrame_Put[6] = 2;
- DataFrame_Put[7] = DEVICEID_1;
- DataFrame_Put[8] = DEVICEID_2;
- DataFrame_Put[9] = 255;
- DataFrame_Put[10] = 255;
- DataFrame_Put[11] = 255;
- DataFrame_Put[12] = 255;
- DataFrame_Put[13] = 002;
- DataFrame_Put[14] = 001;
- PutFrame(&DataFrame_Put);
- led3_count = LED3_COUNT;
- led4_count = LED4_COUNT;
- }else if(dataFrame[3] == 0 && dataFrame[4] == 0 && dataFrame[5] == 0 && dataFrame[6] == 9){
- //收到更新用户信息时间,返回
- DataFrame_Put[3] = 1;
- DataFrame_Put[4] = 0;
- DataFrame_Put[5] = 0;
- DataFrame_Put[6] = 9;
- PutFrame(&DataFrame_Put);
- led3_count = LED3_COUNT;
- led4_count = LED4_COUNT;
- }else if(dataFrame[3] == 0 && dataFrame[4] == 0 && dataFrame[5] == 1 && dataFrame[6] == 1){ // 执行时间15.19 微秒
- //查询温度1:0 0 1 1
- TEMP_init_var();
- DS1_ReadWeather(&ds_M,&ds_L);
- Convert_DS_weather(ds_M, ds_L, &symbol, &hundreds, &decade, &unit, &decimal);
- DataFrame_Put[3] = 1;
- DataFrame_Put[4] = 0;
- DataFrame_Put[5] = 1;
- DataFrame_Put[6] = 1;
- DataFrame_Put[7] = symbol;
- DataFrame_Put[8] = hundreds;
- DataFrame_Put[9] = decade;
- DataFrame_Put[10] = unit;
- DataFrame_Put[11] = decimal;
- PutFrame(&DataFrame_Put);
- led3_count = LED3_COUNT;
- led4_count = LED4_COUNT;
- }else if(dataFrame[3] == 0 && dataFrame[4] == 0 && dataFrame[5] == 1 && dataFrame[6] == 2){
- //查询温度2:0 0 1 2
- TEMP_init_var();
- DS2_ReadWeather(&ds_M,&ds_L);
- Convert_DS_weather(ds_M, ds_L, &symbol, &hundreds, &decade, &unit, &decimal);
- DataFrame_Put[3] = 1;
- DataFrame_Put[4] = 0;
- DataFrame_Put[5] = 1;
- DataFrame_Put[6] = 2;
- DataFrame_Put[7] = symbol;
- DataFrame_Put[8] = hundreds;
- DataFrame_Put[9] = decade;
- DataFrame_Put[10] = unit;
- DataFrame_Put[11] = decimal;
- PutFrame(&DataFrame_Put);
- led3_count = LED3_COUNT;
- led4_count = LED4_COUNT;
- }else if(dataFrame[3] == 0 && dataFrame[4] == 0 && dataFrame[5] == 1 && dataFrame[6] == 3){ // 执行时间15.19 微秒
- //查询温度3:0 0 1 3
- TEMP_init_var();
- DS3_ReadWeather(&ds_M,&ds_L);
- Convert_DS_weather(ds_M, ds_L, &symbol, &hundreds, &decade, &unit, &decimal);
- DataFrame_Put[3] = 1;
- DataFrame_Put[4] = 0;
- DataFrame_Put[5] = 1;
- DataFrame_Put[6] = 3;
- DataFrame_Put[7] = symbol;
- DataFrame_Put[8] = hundreds;
- DataFrame_Put[9] = decade;
- DataFrame_Put[10] = unit;
- DataFrame_Put[11] = decimal;
- PutFrame(&DataFrame_Put);
- led3_count = LED3_COUNT;
- led4_count = LED4_COUNT;
- }else if(dataFrame[3] == 0 && dataFrame[4] == 0 && dataFrame[5] == 1 && dataFrame[6] == 4){
- //查询温度4:0 0 1 4
- TEMP_init_var();
- DS4_ReadWeather(&ds_M,&ds_L);
- Convert_DS_weather(ds_M, ds_L, &symbol, &hundreds, &decade, &unit, &decimal);
- DataFrame_Put[3] = 1;
- DataFrame_Put[4] = 0;
- DataFrame_Put[5] = 1;
- DataFrame_Put[6] = 4;
- DataFrame_Put[7] = symbol;
- DataFrame_Put[8] = hundreds;
- DataFrame_Put[9] = decade;
- DataFrame_Put[10] = unit;
- DataFrame_Put[11] = decimal;
- PutFrame(&DataFrame_Put);
- led3_count = LED3_COUNT;
- led4_count = LED4_COUNT;
- }else if(dataFrame[3] == 0 && dataFrame[4] == 0 && dataFrame[5] == 2 && dataFrame[6] == 1){
- //查询开关1
- DataFrame_Put[3] = 1;
- DataFrame_Put[4] = 0;
- DataFrame_Put[5] = 2;
- DataFrame_Put[6] = 1;
- if(SW1 == 0){
- DataFrame_Put[7] = 1;
- }else{
- DataFrame_Put[7] = 2;
- }
- PutFrame(&DataFrame_Put);
- led3_count = LED3_COUNT;
- led4_count = LED4_COUNT;
- }else if(dataFrame[3] == 0 && dataFrame[4] == 0 && dataFrame[5] == 2 && dataFrame[6] == 2){
- //查询开关2
- DataFrame_Put[3] = 1;
- DataFrame_Put[4] = 0;
- DataFrame_Put[5] = 2;
- DataFrame_Put[6] = 2;
- if(SW2 == 0){
- DataFrame_Put[7] = 1;
- }else{
- DataFrame_Put[7] = 2;
- }
- PutFrame(&DataFrame_Put);
- led3_count = LED3_COUNT;
- led4_count = LED4_COUNT;
- }else if(dataFrame[3] == 0 && dataFrame[4] == 0 && dataFrame[5] == 2 && dataFrame[6] == 3){
- //查询开关3
- DataFrame_Put[3] = 1;
- DataFrame_Put[4] = 0;
- DataFrame_Put[5] = 2;
- DataFrame_Put[6] = 3;
- if(SW3 == 0){
- DataFrame_Put[7] = 1;
- }else{
- DataFrame_Put[7] = 2;
- }
- PutFrame(&DataFrame_Put);
- led3_count = LED3_COUNT;
- led4_count = LED4_COUNT;
- }else if(dataFrame[3] == 0 && dataFrame[4] == 0 && dataFrame[5] == 2 && dataFrame[6] == 4){
- //查询开关3
- DataFrame_Put[3] = 1;
- DataFrame_Put[4] = 0;
- DataFrame_Put[5] = 2;
- DataFrame_Put[6] = 4;
- if(SW4 == 0){
- DataFrame_Put[7] = 1;
- }else{
- DataFrame_Put[7] = 2;
- }
- PutFrame(&DataFrame_Put);
- led3_count = LED3_COUNT;
- led4_count = LED4_COUNT;
- }else if(dataFrame[3] == 2 && dataFrame[4] == 0 && dataFrame[5] == 2 && dataFrame[6] == 1){
- //设置开关1
- if(dataFrame[7] == 1 && dataFrame[8] == 0 && dataFrame[9] == 0 && dataFrame[10] == 0 && dataFrame[11] == 0 && dataFrame[12] == 0 && dataFrame[13] == 0 && dataFrame[14] == 0){
- SW1 = 0;
- }
- else if(dataFrame[7] == 2 && dataFrame[8] == 0 && dataFrame[9] == 0 && dataFrame[10] == 0 && dataFrame[11] == 0 && dataFrame[12] == 0 && dataFrame[13] == 0 && dataFrame[14] == 0){
- SW1 = 1;
- }
- led3_count = LED3_COUNT;
- }else if(dataFrame[3] == 2 && dataFrame[4] == 0 && dataFrame[5] == 2 && dataFrame[6] == 2){
- //设置开关2
- if(dataFrame[7] == 1 && dataFrame[8] == 0 && dataFrame[9] == 0 && dataFrame[10] == 0 && dataFrame[11] == 0 && dataFrame[12] == 0 && dataFrame[13] == 0 && dataFrame[14] == 0){
- SW2 = 0;
- }
- else if(dataFrame[7] == 2 && dataFrame[8] == 0 && dataFrame[9] == 0 && dataFrame[10] == 0 && dataFrame[11] == 0 && dataFrame[12] == 0 && dataFrame[13] == 0 && dataFrame[14] == 0){
- SW2 = 1;
- }
- led3_count = LED3_COUNT;
- }else if(dataFrame[3] == 2 && dataFrame[4] == 0 && dataFrame[5] == 2 && dataFrame[6] == 3){
- //设置开关3
- if(dataFrame[7] == 1 && dataFrame[8] == 0 && dataFrame[9] == 0 && dataFrame[10] == 0 && dataFrame[11] == 0 && dataFrame[12] == 0 && dataFrame[13] == 0 && dataFrame[14] == 0){
- SW3 = 0;
- }
- else if(dataFrame[7] == 2 && dataFrame[8] == 0 && dataFrame[9] == 0 && dataFrame[10] == 0 && dataFrame[11] == 0 && dataFrame[12] == 0 && dataFrame[13] == 0 && dataFrame[14] == 0){
- SW3 = 1;
- }
- led3_count = LED3_COUNT;
- }else if(dataFrame[3] == 2 && dataFrame[4] == 0 && dataFrame[5] == 2 && dataFrame[6] == 4){
- //设置开关4
- if(dataFrame[7] == 1 && dataFrame[8] == 0 && dataFrame[9] == 0 && dataFrame[10] == 0 && dataFrame[11] == 0 && dataFrame[12] == 0 && dataFrame[13] == 0 && dataFrame[14] == 0){
- SW4 = 0;
- }
- else if(dataFrame[7] == 2 && dataFrame[8] == 0 && dataFrame[9] == 0 && dataFrame[10] == 0 && dataFrame[11] == 0 && dataFrame[12] == 0 && dataFrame[13] == 0 && dataFrame[14] == 0){
- SW4 = 1;
- }
- led3_count = LED3_COUNT;
- }
- dataFrame_RI = 0; //置数据帧己读取
- DataFrame_Put_init(); //初始化发送帧,为下一次发送数据做准备
- }
- //LED1运行指示灯闪烁,整个循环在没有接收数据时,执行一次约40us
- if(led1_count > 0){
- led1_count--;
- }else{
- if(led1_count2 == 0){
- led1_count2 = 1;
- }else{
- led1_count2 = 0;
- }
- led1_count = LED1_COUNT;
- }
- if(led1_count > 0){
- if(led1_count2 == 0){
- LED1 = 0;
- }else{
- LED1 = 1;
- }
- led1_count--;
- }
- //收到心跳灯亮20秒
- if(led2_count > 0){
- LED2 = 0;
- led2_count--;
- }else{
- LED2 = 1;
- }
- //有数据接收闪一下
- if(led3_count > 0){
- LED3 = 0;
- led3_count--;
- }else{
- LED3 = 1;
- }
- //有数据发送闪一下
- if(led4_count > 0){
- LED4 = 0;
- led4_count--;
- }else{
- LED4 = 1;
- }
- }
- while(1);
- }
- //初始化输出帧
- void DataFrame_Put_init(){
- DataFrame_Put[3] = 0;
- DataFrame_Put[4] = 0;
- DataFrame_Put[5] = 0;
- DataFrame_Put[6] = 0;
- DataFrame_Put[7] = 0;
- DataFrame_Put[8] = 0;
- DataFrame_Put[9] = 0;
- DataFrame_Put[10] = 0;
- DataFrame_Put[11] = 0;
- DataFrame_Put[12] = 0;
- DataFrame_Put[13] = 0;
- DataFrame_Put[14] = 0;
- }
- //初始化温度值
- void TEMP_init_var(){
- ds_M = 0;
- ds_L = 0;
- symbol = 0; //符号位
- hundreds = 0; //百位
- decade = 0; //十位
- unit = 0; //个位
- decimal = 0; //小数1位
- }
- //初始化
- void UART_init()
- {
- TMOD = 0x20; //T1工作模式2 8位自动重装
- TH1 = 0xfd;
- TL1 = 0xfd; //比特率9600
- TR1 = 1; //启动T1定时器
- SM0 = 0;
- SM1 = 1; //串口工作方式1 10位异步
- REN = 1; //串口允许接收
- EA = 1; //开总中断
- ES = 1; //串口中断打开
- }
- //串口发送一帧数据函数,一帧16个字节
- void PutFrame(uchar *TXStr)
- {
- uchar i = 0;
- while(1){
- SBUF=*TXStr;
- while(TI == 0); //对方接收后TI置1,停止等待
- TI = 0;
- i++;
- if(i > 15){break;}
- TXStr++;
- }
- }
- void UART() interrupt 4
- {
- if(RI) //检测是否接收完成
- {
- uchar temp = SBUF;
- RI = 0;
- // 如果接收的一帧,第一个字节不是包头标志,则抛弃这个字节
- if(dataFrame_temp_count == 0)
- {
- if(temp != DATAFRAME_HEAD)
- return;
- }
- //如果接收的一帧,最后一个字节不是包尾标志,则抛弃这帧数据
- if(dataFrame_temp_count == 15)
- {
- if(temp != DATAFRAME_TAIL){
- dataFrame_temp_count = 0;
- return;
- }
- }
- //将接收的一个字节装入缓冲区
- dataFrame_temp[dataFrame_temp_count] = temp;
- dataFrame_temp_count++;
- //如果一帧数据接收完
- if(dataFrame_temp_count >= 16){
- //如果上一帧还没有读取,则抛弃这一帧
- if(dataFrame_RI == 1){
- dataFrame_temp_count = 0;
- return;
- }
- //拷贝一帧数据,并置这一帧数数没有读取
- dataFrame[0] = dataFrame_temp[0];
- dataFrame[1] = dataFrame_temp[1];
- dataFrame[2] = dataFrame_temp[2];
- dataFrame[3] = dataFrame_temp[3];
- dataFrame[4] = dataFrame_temp[4];
- dataFrame[5] = dataFrame_temp[5];
- dataFrame[6] = dataFrame_temp[6];
- dataFrame[7] = dataFrame_temp[7];
- dataFrame[8] = dataFrame_temp[8];
- dataFrame[9] = dataFrame_temp[9];
- dataFrame[10] = dataFrame_temp[10];
- dataFrame[11] = dataFrame_temp[11];
- dataFrame[12] = dataFrame_temp[12];
- dataFrame[13] = dataFrame_temp[13];
- dataFrame[14] = dataFrame_temp[14];
- dataFrame[15] = dataFrame_temp[15];
-
- dataFrame_temp_count = 0;
- dataFrame_RI = 1;
- }
- }
- }
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