Arduino 74HC595+ML35+数码管实现温度计

电路图.jpg 74HC595 4位数码管 LM35

代码

int SHCP = PD2;
int STCP = PD3;
int DS = PD4;

int sw1 = 8;
int sw2 = 9;
int sw3 = 10;
int sw4 = 11;

// 共阳极数码管数字段码
int table[] = {0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0x9c,0xc6};

void setup()
{
    pinMode(STCP,OUTPUT);
    pinMode(SHCP, OUTPUT);
    pinMode(DS, OUTPUT);
    pinMode(sw1, OUTPUT);
    pinMode(sw2, OUTPUT);
    pinMode(sw3, OUTPUT);
    pinMode(sw4, OUTPUT);
    Serial.begin(9600);
}

void loop()
{
    int val = analogRead(A2);
    int dat = val * (5 / 10.24);
    Serial.print(dat);
    Serial.println("C");

    digitalWrite(STCP,LOW);
    shiftOut(DS,SHCP,LSBFIRST,table[dat / 10]);
    digitalWrite(STCP, HIGH);
    digitalWrite(sw1, HIGH);
    delay(5);
    digitalWrite(sw1, LOW);

    digitalWrite(STCP, LOW);
    shiftOut(DS, SHCP, LSBFIRST, table[dat % 10]);
    digitalWrite(STCP, HIGH);
    digitalWrite(sw2, HIGH);
    delay(5);
    digitalWrite(sw2, LOW);

    digitalWrite(STCP, LOW);
    shiftOut(DS, SHCP, LSBFIRST, table[10]);
    digitalWrite(STCP, HIGH);
    digitalWrite(sw3, HIGH);
    delay(2);
    digitalWrite(sw3, LOW);

    digitalWrite(STCP, LOW);
    shiftOut(DS, SHCP, LSBFIRST, table[11]);
    digitalWrite(STCP, HIGH);
    digitalWrite(sw4, HIGH);
    delay(2);
    digitalWrite(sw4, LOW);
}

重点说明

int table[] = {0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0x9c,0xc6};
分别对应0、1、2、3、4、5、6、7、8、9、0段码表
0x9c；对应的二进制为1001 1100在数码管上显示上方显示圆圈
0xc6；对应二进制1100 0110在数码管上显示C

演示

演示.jpg