此例是從PC鍵盤輸入任何數字都可以顯示(數字會往右Shift).
//Pin connected to latch pin (ST_CP) of 74HC595 const int latchPin = 8; //Pin connected to clock pin (SH_CP) of 74HC595 const int clockPin = 3; ////Pin connected to Data in (DS) of 74HC595 const int dataPin = 9; byte Tab[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0xff}; void setup() { //set pins to output because they are addressed in the main loop pinMode(latchPin, OUTPUT); pinMode(dataPin, OUTPUT); pinMode(clockPin, OUTPUT); Serial.begin(9600); Serial.println("reset"); } void loop() { if (Serial.available() > 0) { // ASCII '0' through '9' characters are // represented by the values 48 through 57. // so if the user types a number from 0 through 9 in ASCII, // you can subtract 48 to get the actual value: int bitToSet = Serial.read() - 48; // write to the shift register with the correct bit set high: digitalWrite(latchPin, LOW); // shift the bits out: shiftOut(dataPin, clockPin, MSBFIRST, Tab[bitToSet]); // turn on the output so the LEDs can light up: digitalWrite(latchPin, HIGH); } }