Arduino - ShftOut23

Back to ShiftOut Tutorial

//**************************************************************//
//  Name    : shiftOutCode, Predefined Dual Array Style         //
//  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 ST_CP of 74HC595
int latchPin = 8;
//Pin connected to SH_CP of 74HC595
int clockPin = 12;
////Pin connected to DS of 74HC595
int dataPin = 11;
//holders for infromation you're going to pass to shifting function
byte dataRED;
byte dataGREEN;
byte dataArrayRED[10];
byte dataArrayGREEN[10];
void setup() {
//set pins to output because they are addressed in the main loop
pinMode(latchPin, OUTPUT);
Serial.begin(9600);
//Arduino doesn't seem to have a way to write binary straight into the code
//so these values are in HEX.  Decimal would have been fine, too.
dataArrayRED[0] = 0xFF; //11111111
dataArrayRED[1] = 0xFE; //11111110
dataArrayRED[2] = 0xFC; //11111100
dataArrayRED[3] = 0xF8; //11111000
dataArrayRED[4] = 0xF0; //11110000
dataArrayRED[5] = 0xE0; //11100000
dataArrayRED[6] = 0xC0; //11000000
dataArrayRED[7] = 0x80; //10000000
dataArrayRED[8] = 0x00; //00000000
dataArrayRED[9] = 0xE0; //11100000
//Arduino doesn't seem to have a way to write binary straight into the code
//so these values are in HEX.  Decimal would have been fine, too.
dataArrayGREEN[0] = 0xFF; //11111111
dataArrayGREEN[1] = 0x7F; //01111111
dataArrayGREEN[2] = 0x3F; //00111111
dataArrayGREEN[3] = 0x1F; //00011111
dataArrayGREEN[4] = 0x0F; //00001111
dataArrayGREEN[5] = 0x07; //00000111
dataArrayGREEN[6] = 0x03; //00000011
dataArrayGREEN[7] = 0x01; //00000001
dataArrayGREEN[8] = 0x00; //00000000
dataArrayGREEN[9] = 0x07; //00000111
//function that blinks all the LEDs
//gets passed the number of blinks and the pause time
blinkAll_2Bytes(2,500);
}
void loop() {
for (int j = 0; j < 10; j++) {
//load the light sequence you want from array
dataRED = dataArrayRED[j];
dataGREEN = dataArrayGREEN[j];
//ground latchPin and hold low for as long as you are transmitting
digitalWrite(latchPin, 0);
//move 'em out
shiftOut(dataPin, clockPin, dataGREEN);
shiftOut(dataPin, clockPin, dataRED);
//return the latch pin high to signal chip that it
//no longer needs to listen for information
digitalWrite(latchPin, 1);
delay(300);
}
}
// 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&#xFFFD;
//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<<i) ) {
pinState= 1;
}
else {
pinState= 0;
}
//Sets the pin to HIGH or LOW depending on pinState
digitalWrite(myDataPin, pinState);
//register shifts bits on upstroke of clock pin
digitalWrite(myClockPin, 1);
//zero the data pin after shift to prevent bleed through
digitalWrite(myDataPin, 0);
}
//stop shifting
digitalWrite(myClockPin, 0);
}
//blinks the whole register based on the number of times you want to
//blink "n" and the pause between them "d"
//starts with a moment of darkness to make sure the first blink
//has its full visual effect.
void blinkAll_2Bytes(int n, int d) {
digitalWrite(latchPin, 0);
shiftOut(dataPin, clockPin, 0);
shiftOut(dataPin, clockPin, 0);
digitalWrite(latchPin, 1);
delay(200);
for (int x = 0; x < n; x++) {
digitalWrite(latchPin, 0);
shiftOut(dataPin, clockPin, 255);
shiftOut(dataPin, clockPin, 255);
digitalWrite(latchPin, 1);
delay(d);
digitalWrite(latchPin, 0);
shiftOut(dataPin, clockPin, 0);
shiftOut(dataPin, clockPin, 0);
digitalWrite(latchPin, 1);
delay(d);
}
}