准备材料
1.一个可以正常使用且安装了Arduino及驱动的电脑
2.一块ESP32开发板
3.一个7.4V电池+两个接电池的导线
4.电池模块（有电）
5.74HC595模块
6.四位数码管
7.旋钮
8.按钮
事先准备
将电池延申出的先接入到“电池接口”中，将5V输出与开发板相连
绝对禁止7.4V电源直接接入开发板！！！否则接入数据线时会导致电脑停机！！！
将四位数码管插入74HC595中（别插错到点阵屏专用孔！）
旋钮电位器插入32（A4）
按钮插入到3
74HC595的V，G分别插入到5V，GND口
L，C，D分别插入到14，13，12口
连接数据线，编程开始！
编程
完整代码
先看完整代码
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148const int dataPin = 12;const int clockPin = 13;const int latchPin = 14;const int keyPin = 3;const int rokeyPin = 32;int KeySta = 0;int de;const byte NUM[] = {0b11111100,0b01100000,0b11011010,0b11110010,0b01100110,0b10110110,0b10111110,0b11100000,0b11111110,0b11110110,0b00000010};void setup() { // put your setup code here, to run once:pinMode(dataPin,OUTPUT);pinMode(clockPin,OUTPUT);pinMode(latchPin,OUTPUT);pinMode(keyPin,INPUT);digitalWrite(clockPin,LOW);digitalWrite(latchPin,LOW);Serial.begin(115200);//delay(10);//siweiqidong(2,3,4,5);//delay(10);}int first,second,third,fourth,minute,second22;void loop() { // put your main code here, to run repeatedly: execute(); if(KeySta == 1){ if(map(analogRead(rokeyPin),0,4095,0,60) < 10){ first = 0; second = String(String(map(analogRead(rokeyPin),0,4095,0,60)).charAt(0)).toInt(); } else{ first = String(String(map(analogRead(rokeyPin),0,4095,0,60)).charAt(0)).toInt(); second = String(String(map(analogRead(rokeyPin),0,4095,0,60)).charAt(1)).toInt(); } minute = map(analogRead(rokeyPin),0,4095,0,60); siweiqidong(first,second,0,0); } else if(KeySta == 2){ if(map(analogRead(rokeyPin),0,4095,0,59) < 10){ third = 0; fourth = String(String(map(analogRead(rokeyPin),0,4095,0,59)).charAt(0)).toInt(); } else{ third = String(String(map(analogRead(rokeyPin),0,4095,0,59)).charAt(0)).toInt(); fourth = String(String(map(analogRead(rokeyPin),0,4095,0,59)).charAt(1)).toInt(); } second22 = map(analogRead(rokeyPin),0,4095,0,59); siweiqidong(first,second,third,fourth); } else if(KeySta == 3){ execute(); //Serial.println(de); if(millis() - de >= 1000){ TimeChan(); de = millis(); //Serial.println("R"); } //Serial.println("Running!"); } else if(KeySta == 0){ for(int i = 0;i < 4;i++){ specialDigitDisplay(i + 1,10); } } if(KeySta != 0){ siweiqidong(first,second,third,fourth); }}void TimeChan(){ if(second22 == 0){ if(minute == 0){ KeySta == 0; } else{ minute = minute - 1; second22 = 59; } } else{ second22 = second22 - 1; } if(minute < 10){ first = 0; second = String(String(minute).charAt(0)).toInt(); } else{ first = String(String(minute).charAt(0)).toInt(); second = String(String(minute).charAt(1)).toInt(); } if(second22 < 10){ third = 0; fourth = String(String(second22).charAt(0)).toInt(); } else{ third = String(String(second22).charAt(0)).toInt(); fourth = String(String(second22).charAt(1)).toInt(); } //Serial.println(String(minute)+":"+String(second22));}void execute(){ if(digitalRead(keyPin) == 0){ //Serial.println(digitalRead(keyPin)); //Serial.println(map(analogRead(rokeyPin),0,4095,0,60)); if(KeySta >= 3){ KeySta = 0; first = 0; second = 0; third = 0; fourth = 0; } else{ KeySta++; } delay(200); } }void siweiqidong(int number1,int number2,int number3,int number4){int results[4];int nym = String(String(number1)+String(number2)+String(number3)+String(number4)).toInt();results[0] = nym / 1000;nym = nym % 1000;results[1] = nym / 100;nym = nym % 100;results[2] = nym / 10;results[3] = nym % 10;/*results[0] = number1;results[1] = number2;results[2] = number3;results[3] = number4;*/for(int i = 0;i <= 3;i++){ specialDigitDisplay(i + 1,results[i]); delay(3); } //delay(10);}void specialDigitDisplay(int digit,int number){byte val = 0;val = bitSet(val,digit - 1);shiftOut(dataPin,clockPin,MSBFIRST,val);shiftOut(dataPin,clockPin,LSBFIRST,~NUM[number]);digitalWrite(latchPin,HIGH);digitalWrite(latchPin,LOW);//delay(10);}
下面我会给出解析
解析
首先的话
123456789const int dataPin = 12;const int clockPin = 13;const int latchPin = 14;const int keyPin = 3;const int rokeyPin = 32;int KeySta = 0;int de;const byte NUM[] = {0b11111100,0b01100000,0b11011010,0b11110010,0b01100110,0b10110110,0b10111110,0b11100000,0b11111110,0b11110110,0b00000010};
这段代码很明显是定义一堆管脚和状态的
接下来看setup中的
12345678910111213void setup() { // put your setup code here, to run once:pinMode(dataPin,OUTPUT);pinMode(clockPin,OUTPUT);pinMode(latchPin,OUTPUT);pinMode(keyPin,INPUT);digitalWrite(clockPin,LOW);digitalWrite(latchPin,LOW);Serial.begin(115200);//delay(10);//siweiqidong(2,3,4,5);//delay(10);}
这一堆pinMode都是调整接口状态的，包括下面的digitalWrite，都是初始化数码管的。
底部的Serial.begin是初始化串口的，无用。包括底部的被注释的，都是开发时为了方便找错而设立的。
接下来，我新建了一堆变量
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748int first,second,third,fourth,minute,second22;void loop() { // put your main code here, to run repeatedly: execute(); if(KeySta == 1){ if(map(analogRead(rokeyPin),0,4095,0,60) < 10){ first = 0; second = String(String(map(analogRead(rokeyPin),0,4095,0,60)).charAt(0)).toInt(); } else{ first = String(String(map(analogRead(rokeyPin),0,4095,0,60)).charAt(0)).toInt(); second = String(String(map(analogRead(rokeyPin),0,4095,0,60)).charAt(1)).toInt(); } minute = map(analogRead(rokeyPin),0,4095,0,60); siweiqidong(first,second,0,0); } else if(KeySta == 2){ if(map(analogRead(rokeyPin),0,4095,0,59) < 10){ third = 0; fourth = String(String(map(analogRead(rokeyPin),0,4095,0,59)).charAt(0)).toInt(); } else{ third = String(String(map(analogRead(rokeyPin),0,4095,0,59)).charAt(0)).toInt(); fourth = String(String(map(analogRead(rokeyPin),0,4095,0,59)).charAt(1)).toInt(); } second22 = map(analogRead(rokeyPin),0,4095,0,59); siweiqidong(first,second,third,fourth); } else if(KeySta == 3){ execute(); //Serial.println(de); if(millis() - de >= 1000){ TimeChan(); de = millis(); //Serial.println("R"); } //Serial.println("Running!"); } else if(KeySta == 0){ for(int i = 0;i < 4;i++){ specialDigitDisplay(i + 1,10); } } if(KeySta != 0){ siweiqidong(first,second,third,fourth); }}
先不说变量都是干啥的，直接讲loop中的
execute函数是检测的，再下面会有说明
之后检测按钮的按压次数，如果按了一次，就对分钟进行改动，加if是让“9”变成“09”
然后对小时约束，最大值为60，最小为1，通过转动旋钮更改
按第二次，更改秒，同小时
按第三次，正式开始计时，先进行检测，再看运行时间与之前记录时间是否大于等于1000ms（1秒）
这里不用delay是为了防止程序计算与数码管渲染导致的延时，
并且delay函数也影响四位数码管渲染效果，TimeChan是更改数码管的函数，再更新de的值，记录
如果按键计数的值为0，就清空成为"----"
不等于0就实时渲染数码管
12345678910111213141516171819202122232425262728293031void TimeChan(){ if(second22 == 0){ if(minute == 0){ KeySta == 0; } else{ minute = minute - 1; second22 = 59; } } else{ second22 = second22 - 1; } if(minute < 10){ first = 0; second = String(String(minute).charAt(0)).toInt(); } else{ first = String(String(minute).charAt(0)).toInt(); second = String(String(minute).charAt(1)).toInt(); } if(second22 < 10){ third = 0; fourth = String(String(second22).charAt(0)).toInt(); } else{ third = String(String(second22).charAt(0)).toInt(); fourth = String(String(second22).charAt(1)).toInt(); } //Serial.println(String(minute)+":"+String(second22));}
观察渲染四位数码管的函数，当秒为0时，检测分钟，分钟等于0就结束并改变按钮状态
否则分钟-1，秒变为59，这里也是方便按下按钮直接停止计时。
下面是当分钟小于10时，秒小于10时，在十位加个“0”
1234567891011121314151617void execute(){ if(digitalRead(keyPin) == 0){ //Serial.println(digitalRead(keyPin)); //Serial.println(map(analogRead(rokeyPin),0,4095,0,60)); if(KeySta >= 3){ KeySta = 0; first = 0; second = 0; third = 0; fourth = 0; } else{ KeySta++; } delay(200); } }
这段就是一个简单的按键计数程序，大于等于3时直接清空所有，不是的话就加一下按键计数
1234567891011121314151617181920212223242526272829void siweiqidong(int number1,int number2,int number3,int number4){int results[4];int nym = String(String(number1)+String(number2)+String(number3)+String(number4)).toInt();results[0] = nym / 1000;nym = nym % 1000;results[1] = nym / 100;nym = nym % 100;results[2] = nym / 10;results[3] = nym % 10;/*results[0] = number1;results[1] = number2;results[2] = number3;results[3] = number4;*/for(int i = 0;i <= 3;i++){ specialDigitDisplay(i + 1,results[i]); delay(3); } //delay(10);}void specialDigitDisplay(int digit,int number){byte val = 0;val = bitSet(val,digit - 1);shiftOut(dataPin,clockPin,MSBFIRST,val);shiftOut(dataPin,clockPin,LSBFIRST,~NUM[number]);digitalWrite(latchPin,HIGH);digitalWrite(latchPin,LOW);//delay(10);}
这段代码是专门负责渲染四位数码管的函数，没什么可解释的
好了，你学会了吗？