//**************************************************************// // Name : shiftOutCode, 74HC595 Dual One By One // // Author : Carlyn Maw, Tom Igoe // // Date : 25 Oct, 2006 // // Version : 1.0 // // Notes : Code for using a 74HC595 Shift Register // // : to count from 0 to 255 // //**************************************************************// //Pin connected to RCLK pin 12 of 74HC595 (Lath) int latchPin = 8; //Pin connected to SRCLK pin 11 of 74HC595 (Clock) int clockPin = 12; ////Pin connected to SER pin 14 of 74HC595 (Data) int dataPin = 11; //holder for infromation you're going to pass to shifting function byte data = 0; void setup() { //set pins to output because they are addressed in the main loop pinMode(latchPin, OUTPUT); } void loop() { //function that blinks all the LEDs //gets passed the number of blinks and the pause time blinkAll_2Bytes(1,500); // light each pin one by one using a function A for (int j = 0; j < 8; j++) { //ground latchPin and hold low for as long as you are transmitting digitalWrite(latchPin, 0); //red LEDs lightShiftPinA(7-j); //green LEDs lightShiftPinA(j); //return the latch pin high to signal chip that it //no longer needs to listen for information digitalWrite(latchPin, 1); delay(1000); } // light each pin one by one using a function A for (int j = 0; j < 8; j++) { //ground latchPin and hold low for as long as you are transmitting digitalWrite(latchPin, 0); //red LEDs lightShiftPinB(j); //green LEDs lightShiftPinB(7-j); //return the latch pin high to signal chip that it //no longer needs to listen for information digitalWrite(latchPin, 1); delay(1000); } } //This function uses bitwise math to move the pins up void lightShiftPinA(int p) { //defines a local variable int pin; //this is line uses a bitwise operator //shifting a bit left using << is the same //as multiplying the decimal number by two. pin = 1<< p; //move 'em out shiftOut(dataPin, clockPin, pin); } //This function uses that fact that each bit in a byte //is 2 times greater than the one before it to //shift the bits higher void lightShiftPinB(int p) { //defines a local variable int pin; //start with the pin = 1 so that if 0 is passed to this //function pin 0 will light. pin = 1; for (int x = 0; x < p; x++) { pin = pin * 2; } //move 'em out shiftOut(dataPin, clockPin, pin); } // the heart of the program void shiftOut(int myDataPin, int myClockPin, byte myDataOut) { // This shifts 8 bits out MSB first, //on the rising edge of the clock, //clock idles low //internal function setup int i=0; int pinState; pinMode(myClockPin, OUTPUT); pinMode(myDataPin, OUTPUT); //clear everything out just in case to //prepare shift register for bit shifting digitalWrite(myDataPin, 0); digitalWrite(myClockPin, 0); //for each bit in the byte myDataOut� //NOTICE THAT WE ARE COUNTING DOWN in our for loop //This means that %00000001 or "1" will go through such //that it will be pin Q0 that lights. for (i=7; i>=0; i--) { digitalWrite(myClockPin, 0); //if the value passed to myDataOut and a bitmask result // true then... so if we are at i=6 and our value is // %11010100 it would the code compares it to %01000000 // and proceeds to set pinState to 1. if ( myDataOut & (1<