第十六届蓝桥杯单片机组4T模拟赛二
难点:
PCF8591同时测量两条通道数据
避免重复触发
采集触发时的时间数据存放
未采集的数据显示
清空数据
如果你系统的学习过C语言和数据结构与算法,解决本题还是很轻松的。
附件:第十六届蓝桥杯单片机组4T模拟赛二
一、基础知识
- PCF8591:如果你在读取通道 1 后立即读取通道 3,会导致以下问题:
1.电压参数未稳定:PCF8591 在切换通道后,需要一定的时间来稳定电压参数。
如果立即读取下一个通道,可能会导致读取的值不准确。
2.通道切换延迟:PCF8591 的通道切换需要时间,具体取决于芯片的采样速率和硬件设计。如果没有足够的延迟,读取的值可能仍然是上一个通道的值。
解决方法已经在另一篇文章给出了:PCF8591一次读取多条通道导致测量值不准确的原因及解决方法- 通过PCF8591采集的电压数据不稳定:可以使用以下方法:
1.均值滤波:对多次采样结果取平均值
2.中值滤波:对多次采样结果取中值
3.滑动平均滤波:维护一个滑动窗口,计算窗口内数据的平均值
4.卡尔曼滤波:适用于动态系统的高级滤波算法
本篇文章使用的是均值滤波,其他几种在单片机中有点大炮打蚊子的感觉,在以后的嵌入式系列再作介绍。string.h
中的两个常用函数
1.memset
memset
用于将一段内存区域的内容设置为指定的值
(1)函数原型:void* memset(void* ptr, int value, size_t num);
(2)参数:
ptr
:指向要设置的内存区域的指针
value
:要设置的值(以int
形式传递,但实际按unsigned char
处理
num
:要设置的字节数
(3)功能:
将ptr
指向的内存区域的前num
个字节设置为value
2.memcpy
memcpy 用于将一段内存区域的内容复制到另一段内存区域。
(1)函数原型:void* memcpy(void* dest, const void* src, size_t num);
(2)参数:
dest
:指向目标内存区域的指针
src
:指向源内存区域的指针
num
:要复制的字节数
(3)功能:
将src
指向的内存区域的前num
个字节复制到dest
指向的内存区域
二、板子现象演示
1.时间界面
上电显示时间界面,从23时59分50秒开始计时,同时LED1点亮,其余指示灯熄灭。
2.数据界面
按下S4切换成数据页面,数码管显示RB2和RD1的值,指示灯L2点亮。
3.历史查询界面
按下S4切换历史查询界面,未触发数据采集时显示-
,指示灯L3点亮,该页面按下S5切换历史查询子界面。
4.触发采集
任意界面光敏电阻电压<RB2电压时触发采集(持续处于该状态时不触发),由于手机拍照遮光触发三次。
触发采集时亮的灯是L8,下面这张图是错误的,后面的Led模块已经修改好了。
5.触发三次采集后的历史查询页面
6.清空记录时间
三、数码管模块
1.添加P
R
C
-
的段码
code unsigned char Seg_Table[] =
{
0xc0, //0
0xf9, //1
0xa4, //2
0xb0, //3
0x99, //4
0x92, //5
0x82, //6
0xf8, //7
0x80, //8
0x90, //9
0xff, //空
0xbf, //-
0x8c, //P
0xc1, //U
0x88, //A
0xc6, //C
};
void SegDisp(unsigned char wela, unsigned char dula, unsigned char point)
{
P0 = 0xff;
P2 = P2 & 0x1f | 0xe0;
P2 &= 0x1f;
P0 = (0x01 << wela);
P2 = P2 & 0x1f | 0xc0;
P2 &= 0x1f;
P0 = Seg_Table[dula];
if(point)
P0 &= 0x7f;
P2 = P2 & 0x1f | 0xe0;
P2 &= 0x1f;
}
2.时间页面
- 添加DS1302底层代码
#include <STC15F2K60S2.H>
#include <intrins.h>
sbit SCK = P1^7;
sbit RST = P1^3;
sbit SDA = P2^3;
void Write_Ds1302(unsigned char temp)
{
unsigned char i;
for (i=0;i<8;i++)
{
SCK = 0;
SDA = temp&0x01;
temp>>=1;
SCK=1;
}
}
void Write_Ds1302_Byte( unsigned char address,unsigned char dat )
{
RST=0; _nop_();
SCK=0; _nop_();
RST=1; _nop_();
Write_Ds1302(address);
Write_Ds1302(dat);
RST=0;
}
unsigned char Read_Ds1302_Byte ( unsigned char address )
{
unsigned char i,temp=0x00;
RST=0; _nop_();
SCK=0; _nop_();
RST=1; _nop_();
Write_Ds1302(address);
for (i=0;i<8;i++)
{
SCK=0;
temp>>=1;
if(SDA)
temp|=0x80;
SCK=1;
}
RST=0; _nop_();
SCK=0; _nop_();
SCK=1; _nop_();
SDA=0; _nop_();
SDA=1; _nop_();
return (temp);
}
code unsigned char DS1302_Arr[4] = {0x84,0x82,0x80,0x8E};
void SetRtc(unsigned char *ucRtc)
{
unsigned char i;
Write_Ds1302_Byte(DS1302_Arr[3],0x00);
for(i = 0; i < 3; i++)
Write_Ds1302_Byte(DS1302_Arr[i],ucRtc[i]);
Write_Ds1302_Byte(DS1302_Arr[3],0x80);
}
void GetRtc(unsigned char *ucRtc)
{
unsigned char i;
for(i = 0; i < 3; i++)
ucRtc[i] = Read_Ds1302_Byte(DS1302_Arr[i]+1);
}
- 在
main.c
函数中的DS1302
数据处理函数
pdata u8 ucRtc[3] = {0x23,0x59,0x50};
void DS1302Proc()
{
GetRtc(ucRtc);
}
void main()
{
SystemInit();
Timer0_Init();
SetRtc(ucRtc);//设定时间
while(1)
{
DS1302Proc();
}
}
- 数码管显示
typedef unsigned char u8;
typedef unsigned int u16;
typedef unsigned long int u32;
idata u8 SegPos;//数码管扫描位
idata u8 SegMode;//数码管显示页面
pdata u8 SegBuf[8] = {10,10,10,10,10,10,10,10};//数码管数据缓存区
pdata u8 SegPoint[8] = {0,0,0,0,0,0,0,0};//数码管小数点使能位
pdata u8 ucRtc[3] = {0x23,0x59,0x50};//时钟
void SegProc()
{
unsigned char i;
switch(SegMode)
{
case 0:
SegBuf[2] = SegBuf[5] = 11;//-
for(i = 0; i < 3; i++)
{
SegBuf[3*i] = ucRtc[i] / 16;
SegBuf[3*i+1] = ucRtc[i] % 16;
}
break;
}
}
3.数据页面
- iic底层
对AD处理时使用的方法是连续读取两次,丢弃第一次的值,并且使用均值滤波(不使用滤波也行)。
#include <STC15F2K60S2.H>
#include <intrins.h>
#define DELAY_TIME 5
sbit scl = P2^0;
sbit sda = P2^1;
static void I2C_Delay(unsigned char n)
{
do
{
_nop_();_nop_();_nop_();_nop_();_nop_();
_nop_();_nop_();_nop_();_nop_();_nop_();
_nop_();_nop_();_nop_();_nop_();_nop_();
}
while(n--);
}
void I2CStart(void)
{
sda = 1;
scl = 1;
I2C_Delay(DELAY_TIME);
sda = 0;
I2C_Delay(DELAY_TIME);
scl = 0;
}
//
void I2CStop(void)
{
sda = 0;
scl = 1;
I2C_Delay(DELAY_TIME);
sda = 1;
I2C_Delay(DELAY_TIME);
}
//
void I2CSendByte(unsigned char byt)
{
unsigned char i;
for(i=0; i<8; i++){
scl = 0;
I2C_Delay(DELAY_TIME);
if(byt & 0x80){
sda = 1;
}
else{
sda = 0;
}
I2C_Delay(DELAY_TIME);
scl = 1;
byt <<= 1;
I2C_Delay(DELAY_TIME);
}
scl = 0;
}
//
unsigned char I2CReceiveByte(void)
{
unsigned char da;
unsigned char i;
for(i=0;i<8;i++){
scl = 1;
I2C_Delay(DELAY_TIME);
da <<= 1;
if(sda)
da |= 0x01;
scl = 0;
I2C_Delay(DELAY_TIME);
}
return da;
}
//
unsigned char I2CWaitAck(void)
{
unsigned char ackbit;
scl = 1;
I2C_Delay(DELAY_TIME);
ackbit = sda;
scl = 0;
I2C_Delay(DELAY_TIME);
return ackbit;
}
//
void I2CSendAck(unsigned char ackbit)
{
scl = 0;
sda = ackbit;
I2C_Delay(DELAY_TIME);
scl = 1;
I2C_Delay(DELAY_TIME);
scl = 0;
sda = 1;
I2C_Delay(DELAY_TIME);
}
unsigned char Ad(unsigned char add)
{
unsigned char temp;
I2CStart();
I2CSendByte(0x90);
I2CWaitAck();
I2CSendByte(add);
I2CWaitAck();
I2CStart();
I2CSendByte(0x91);
I2CWaitAck();
temp = I2CReceiveByte();
I2CSendAck(1);
I2CStop();
I2CStart();
I2CSendByte(0x90);
I2CWaitAck();
I2CSendByte(add);
I2CWaitAck();
I2CStart();
I2CSendByte(0x91);
I2CWaitAck();
temp = I2CReceiveByte();
I2CSendAck(1);
I2CStop();
return temp;
}
unsigned char AverageFilter(unsigned char add)
{
unsigned char i;
unsigned int sum = 0;
for (i = 0; i < 10; i++)
{
sum += Ad(add);// 多次采样
}
return (unsigned char)(sum / 10);
}
main.c
中的AD数据处理函数ADProc()
idata u16 RD1_100x, RB2_100x;//RD1、RB2放大100倍
void ADProc()
{
RD1_100x = AverageFilter(0x01) / 51.0 * 100;
RB2_100x = AverageFilter(0x03) / 51.0 * 100;
}
- 数码管显示
void SegProc()
{
unsigned char i;
if(!record)
{
switch(SegMode)
{
case 0:
//...
break;
case 1:
SegBuf[0] = 12;//P
SegBuf[1] = RD1_100x / 100;
SegBuf[2] = RD1_100x / 10 % 10;
SegBuf[3] = RD1_100x % 10;
SegBuf[4] = 13;//U
SegBuf[5] = RB2_100x / 100;
SegBuf[6] = RB2_100x / 10 % 10;
SegBuf[7] = RB2_100x % 10;
SegPoint[1] = SegPoint[5] = 1;
break;
}
}
}
4.历史查询界面
由于历史查询界面中记录的是最近三次的触发时间,这边为了方便
使用二维数组pdata u8 rtc_record[3][3];
来记录三组时间
定义idata u8 rtc_record_x;
为二维数组的行索引
由于时钟的小时不可能为24,所以二维数组的初值赋值为0x24
,在数码管就可以通过判断二维数组的rtc_record[rtc_record_x][0]
是否为0x24进行判断是否为空。
idata u8 rtc_record_x;
pdata u8 rtc_record[3][3] = {0x24,0x24,0x24,0x24,0x24,0x24,0x24,0x24,0x24};
void SegProc()
{
unsigned char i;
if(!record)
{
switch(SegMode)
{
case 0:
//...
break;
case 1:
//...
break;
case 2:
SegBuf[0] = 14;
SegBuf[1] = rtc_record_x + 1;
SegPoint[1] = SegPoint[5] = 0;
//如果该组数据未采集,则除了前两位其余显示-
if(rtc_record[rtc_record_x][0] == 0x24)
{
SegBuf[2] = 11;
SegBuf[3] = 11;
SegBuf[4] = 11;
SegBuf[5] = 11;
SegBuf[6] = 11;
SegBuf[7] = 11;
}
//该组数据已采集,正常显示
else
for(i = 0; i < 3; i++)
{
SegBuf[2*i+2] = rtc_record[rtc_record_x][i] / 16;
SegBuf[2*i+3] = rtc_record[rtc_record_x][i] % 16;
}
break;
}
}
5.触发采集
/*变量定义*/
idata u8 rtc_record_x;//二维数组行索引
pdata u8 rtc_record[3][3] = {0x24,0x24,0x24,0x24,0x24,0x24,0x24,0x24,0x24};//二维数组存放记录的时间
idata bit record;//触发标志位
idata bit has_record;//重复触发检测位
在实现该功能,应采取从大到小的方法来实现
- 当采集到光敏电压值 < RB2 电压值时,触发 1 次
void ADProc()
{
RD1_100x = AverageFilter(0x01) / 51.0 * 100;
RB2_100x = AverageFilter(0x03) / 51.0 * 100;
//光敏电压:RD1
if(RD1_100x < RB2_100x && !record)
{
record = 1;
GetRtc(rtc_record[0]);//采集第一组时间
}
}
- 触发后,立即切换到“触发界面”,显示本次触发时间, 3s 内不可重复触发。 3 秒后返回“原状态”
idata u16 Time_3s;
void ADProc()
{
RD1_100x = AverageFilter(0x01) / 51.0 * 100;
RB2_100x = AverageFilter(0x03) / 51.0 * 100;
//光敏电压:RD1
if(RD1_100x < RB2_100x && !record)
{
record = 1;
GetRtc(rtc_record[0]);//采集第一组时间
}
if(RD1_100x >= RB2_100x)
has_record = 0;
}
void Timer0_Isr(void) interrupt 1
{
//systick++;
if(++SegPos == 8) SegPos = 0;
SegDisp(SegPos,SegBuf[SegPos],SegPoint[SegPos]);
if(record)
if(++Time_3s == 3000)
{
Time_3s = 0;
record = 0;
}
}
- 接下来考虑不重复触发
idata bit has_record;//重复触发检测位
void ADProc()
{
RD1_100x = AverageFilter(0x01) / 51.0 * 100;
RB2_100x = AverageFilter(0x03) / 51.0 * 100;
//光敏电压:RD1
if((RD1_100x < RB2_100x) && !record && !has_record)
{
has_record = 1;
record = 1;
GetRtc(rtc_record[0]);//采集第一组时间
}
if(RD1_100x >= RB2_100x)
has_record = 0;
}
- 接下来写一个函数,实现以下功能
触发后, “历史查询界面”,记录本次触发时间。越早记录的数据,索引值越大,最近一次触发时间索引值
为 1。历史查询界面可记录最近 3 次的触发时间。
(1)数据移动
for (i = 2; i > 0; i--)
memcpy(rtc_record[i], rtc_record[i - 1], 3);
将rtc_record[1] 的数据复制到 rtc_record[2]
将rtc_record[0] 的数据复制到 rtc_record[1]
每次移动的数据长度为 3 个字节(时、分、秒)
(2)获取新数据
GetRtc(rtc_record[0]);
调用 GetRtc() 函数,将新数据存储到 rtc_record[0] 中。
(3)代码
void UpdateRtcRecord()
{
unsigned char i;
for(i = 2; i > 0; i--)
memcpy(rtc_record[i],rtc_record[i-1],3);
GetRtc(rtc_record[0]);
}
- 调用
UpdateRtcRecord()
void UpdateRtcRecord()
{
unsigned char i;
for(i = 2; i > 0; i--)
memcpy(rtc_record[i],rtc_record[i-1],3);
GetRtc(rtc_record[0]);
}
void ADProc()
{
RD1_100x = AverageFilter(0x01) / 51.0 * 100;
RB2_100x = AverageFilter(0x03) / 51.0 * 100;
//光敏电压:RD1
if((RD1_100x < RB2_100x) && !record && !has_record)
{
has_record = 1;
record = 1;
UpdateRtcRecord();
}
if(RD1_100x >= RB2_100x)
has_record = 0;
}
6.数码管完整代码
void SegProc()
{
unsigned char i;
if(!record)//没有处于记录页面
{
switch(SegMode)
{
case 0:
SegBuf[2] = SegBuf[5] = 11;
for(i = 0; i < 3; i++)
{
SegBuf[3*i] = ucRtc[i] / 16;
SegBuf[3*i+1] = ucRtc[i] % 16;
}
break;
case 1:
SegBuf[0] = 12;
SegBuf[1] = RD1_100x / 100;
SegBuf[2] = RD1_100x / 10 % 10;
SegBuf[3] = RD1_100x % 10;
SegBuf[4] = 13;
SegBuf[5] = RB2_100x / 100;
SegBuf[6] = RB2_100x / 10 % 10;
SegBuf[7] = RB2_100x % 10;
SegPoint[1] = SegPoint[5] = 1;
break;
case 2:
SegBuf[0] = 14;
SegBuf[1] = rtc_record_x + 1;
SegPoint[1] = SegPoint[5] = 0;
if(rtc_record[rtc_record_x][0] == 0x24)
{
SegBuf[2] = 11;
SegBuf[3] = 11;
SegBuf[4] = 11;
SegBuf[5] = 11;
SegBuf[6] = 11;
SegBuf[7] = 11;
}
else
for(i = 0; i < 3; i++)
{
SegBuf[2*i+2] = rtc_record[rtc_record_x][i] / 16;
SegBuf[2*i+3] = rtc_record[rtc_record_x][i] % 16;
}
break;
}
}
else//处于记录页面
{
SegBuf[0] = 13;
SegBuf[1] = 13;
SegPoint[1] = SegPoint[5] = 0;
for(i = 0; i < 3; i++)
{
SegBuf[2*i+2] = rtc_record[0][i] / 16;
SegBuf[2*i+3] = rtc_record[0][i] % 16;
}
}
}
四、按键模块
1.底层代码
#include <STC15F2K60S2.H>
unsigned char KeyDisp()
{
unsigned char temp = 0;
P44 = 0;
P42 = 1;
P35 = 1;
P34 = 1;
if(P32 == 0)temp = 5;
if(P33 == 0)temp = 4;
P44 = 1;
P42 = 0;
P35 = 1;
P34 = 1;
if(P33 == 0)temp = 8;
return temp;
}
2.功能处理
idata u8 rtc_record_x;//二维数组行索引
pdata u8 rtc_record[3][3] = {0x24,0x24,0x24,0x24,0x24,0x24,0x24,0x24,0x24};//二维数组存放记录的时间
void KeyProc()
{
KeyVal = KeyDisp();
KeyDown = KeyVal & ~KeyOld;
KeyUp = ~KeyVal & KeyOld;
KeyOld = KeyVal;
switch(KeyDown)
{
case 4://页面流转
if(++SegMode == 3) SegMode = 0;
//每次进入历史查询页面时,索引值默认为1
if(!SegMode) rtc_record_x = 0;
break;
case 5://历史查询页面子页面控制
if(SegMode == 2)
if(++rtc_record_x == 3)
rtc_record_x = 0;
break;
case 8://清空记录的数据
if(SegMode == 2)
{
rtc_record_x = 0;
//memset:将`rtc_record`指向的内存区域的前`9`个字节设置为`0x24`
//在数码管中判断数据为空时比较数据是0x24
memset(rtc_record,0x24,9);
}
break;
}
}
五、Led模块
看到这种指定页面指定指示灯亮的依旧使用互斥点亮
pdata u8 ucLed[8] = {0,0,0,0,0,0,0,0};
void LedProc()
{
unsigned char i;
for(i = 0; i < 3; i++)
ucLed[i] = (SegMode == i);
ucLed[7] = record;
LedDisp(ucLed);
}
六、完整代码(各模块退出处理请自行添加)
#include <STC15F2K60S2.H>
#include <string.h>
#include "Init.h"
#include "Key.h"
#include "Seg.h"
#include "Led.h"
#include "iic.h"
#include "ds1302.h"
typedef unsigned char u8;
typedef unsigned int u16;
idata u8 SegPos;
idata u8 SegMode;
idata u8 KeyVal, KeyDown, KeyUp, KeyOld;
idata u8 rtc_record_x;
idata u16 RD1_100x, RB2_100x;
idata u16 Time_3s;
pdata u8 SegBuf[8] = {10,10,10,10,10,10,10,10};
pdata u8 SegPoint[8] = {0,0,0,0,0,0,0,0};
pdata u8 ucRtc[3] = {0x23,0x59,0x50};
pdata u8 rtc_record[3][3] = {0x24,0x24,0x24,0x24,0x24,0x24,0x24,0x24,0x24};
pdata u8 ucLed[8] = {0,0,0,0,0,0,0,0};
idata bit record;//触发标志位
idata bit has_record;//重复触发检测位
void UpdateRtcRecord()
{
unsigned char i;
for(i = 2; i > 0; i--)
memcpy(rtc_record[i],rtc_record[i-1],3);
GetRtc(rtc_record[0]);
}
void KeyProc()
{
KeyVal = KeyDisp();
KeyDown = KeyVal & ~KeyOld;
KeyUp = ~KeyVal & KeyOld;
KeyOld = KeyVal;
switch(KeyDown)
{
case 4:
if(++SegMode == 3) SegMode = 0;
if(!SegMode) rtc_record_x = 0;
break;
case 5:
if(SegMode == 2)
if(++rtc_record_x == 3)
rtc_record_x = 0;
break;
case 8:
if(SegMode == 2)
{
rtc_record_x = 0;
memset(rtc_record,0x24,9);
}
break;
}
}
void SegProc()
{
unsigned char i;
if(!record)
{
switch(SegMode)
{
case 0:
SegBuf[2] = SegBuf[5] = 11;
for(i = 0; i < 3; i++)
{
SegBuf[3*i] = ucRtc[i] / 16;
SegBuf[3*i+1] = ucRtc[i] % 16;
}
break;
case 1:
SegBuf[0] = 12;
SegBuf[1] = RD1_100x / 100;
SegBuf[2] = RD1_100x / 10 % 10;
SegBuf[3] = RD1_100x % 10;
SegBuf[4] = 13;
SegBuf[5] = RB2_100x / 100;
SegBuf[6] = RB2_100x / 10 % 10;
SegBuf[7] = RB2_100x % 10;
SegPoint[1] = SegPoint[5] = 1;
break;
case 2:
SegBuf[0] = 14;
SegBuf[1] = rtc_record_x + 1;
SegPoint[1] = SegPoint[5] = 0;
if(rtc_record[rtc_record_x][0] == 0x24)
{
SegBuf[2] = 11;
SegBuf[3] = 11;
SegBuf[4] = 11;
SegBuf[5] = 11;
SegBuf[6] = 11;
SegBuf[7] = 11;
}
else
for(i = 0; i < 3; i++)
{
SegBuf[2*i+2] = rtc_record[rtc_record_x][i] / 16;
SegBuf[2*i+3] = rtc_record[rtc_record_x][i] % 16;
}
break;
}
}
else
{
SegBuf[0] = 13;
SegBuf[1] = 13;
SegPoint[1] = SegPoint[5] = 0;
for(i = 0; i < 3; i++)
{
SegBuf[2*i+2] = rtc_record[0][i] / 16;
SegBuf[2*i+3] = rtc_record[0][i] % 16;
}
}
}
void LedProc()
{
unsigned char i;
for(i = 0; i < 3; i++)
ucLed[i] = (SegMode == i);
ucLed[7] = record;
LedDisp(ucLed);
}
void DS1302Proc()
{
GetRtc(ucRtc);
}
void ADProc()
{
RD1_100x = AverageFilter(0x01) / 51.0 * 100;
RB2_100x = AverageFilter(0x03) / 51.0 * 100;
//光敏电压:RD1
if((RD1_100x < RB2_100x) && !record && !has_record)
{
has_record = 1;
record = 1;
UpdateRtcRecord();
}
if(RD1_100x >= RB2_100x)
has_record = 0;
}
void Timer0_Init(void) //1毫秒@12.000MHz
{
AUXR &= 0x7F; //定时器时钟12T模式
TMOD &= 0xF0; //设置定时器模式
TL0 = 0x18; //设置定时初始值
TH0 = 0xFC; //设置定时初始值
TF0 = 0; //清除TF0标志
TR0 = 1; //定时器0开始计时
ET0 = 1; //使能定时器0中断
EA = 1;
}
void Timer0_Isr(void) interrupt 1
{
if(++SegPos == 8) SegPos = 0;
SegDisp(SegPos,SegBuf[SegPos],SegPoint[SegPos]);
if(record)
if(++Time_3s == 3000)
{
Time_3s = 0;
record = 0;
}
}
void main()
{
SystemInit();
Timer0_Init();
SetRtc(ucRtc);
while(1)
{
}
}