I am following the shiftout tutorial on the site and have completed the counting upto 256 using one 595 shift register. I have added the second 595 and connected a further 8 Led's. This counts up on the Red Led's and down on the Green Led's still using 256, what I want to do is count up using all the Led's. So thats Bin 1111111111111111 = 65535. How would I change the code to achieve this?
//**************************************************************//
// Name : shiftOutCode, Dual Binary Counters //
// 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;
void setup() {
//Start Serial for debuging purposes
Serial.begin(9600);
//set pins to output because they are addressed in the main loop
pinMode(latchPin, OUTPUT);
}
void loop() {
//count up routine
for (int j = 0; j < 256; j++) {
//ground latchPin and hold low for as long as you are transmitting
digitalWrite(latchPin, 0);
//count up on GREEN LEDs
shiftOut(dataPin, clockPin, j);
//count down on RED LEDs
shiftOut(dataPin, clockPin, 255-j);
//return the latch pin high to signal chip that it
//no longer needs to listen for information
digitalWrite(latchPin, 1);
delay(1000);
}
}
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<<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);
}
Thanks that looks like what I need. Any example of how i would incorporate this into the shiftout code?
//**************************************************************//
// Name : shiftOutCode, Hello World
// Author : Carlyn Maw,Tom Igoe, David A. Mellis
// Date : 25 Oct, 2006
// Modified: 23 Mar 2010
// Version : 2.0
// 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;
void setup() {
//set pins to output so you can control the shift register
pinMode(latchPin, OUTPUT);
pinMode(clockPin, OUTPUT);
pinMode(dataPin, OUTPUT);
}
void loop() {
// count from 0 to 255 and display the number
// on the LEDs
for (int numberToDisplay = 0; numberToDisplay < 256; numberToDisplay++) {
// take the latchPin low so
// the LEDs don't change while you're sending in bits:
digitalWrite(latchPin, LOW);
// shift out the bits:
shiftOut(dataPin, clockPin, MSBFIRST, numberToDisplay);
//take the latch pin high so the LEDs will light up:
digitalWrite(latchPin, HIGH);
// pause before next value:
delay(500);
}
}
thanks that seemed to work. i was surprised to see the second 595 counts first. so i swapped the LED inputs about. So the second 595 has the first LED's attached and the first 595 has the second LED's. I have the serial monitor printing and it counts up fine.
Just out of interest since I have this setup how would I specify a single number to display like "43690" which would hopefully display 1010101010101010 (On, off, On off etc)?
"core.a(main.cpp.o): In function `main':
C:\Program Files\ARDUINO\arduino-0022\hardware\arduino\cores\arduino/main.cpp:10: undefined reference to `loop'
Cant see where its gone wrong?
I have read you right Mike Void (display) instead of Void (loop)?
//**************************************************************//
// Name : shiftOutCode, Hello World
// Author : Carlyn Maw,Tom Igoe, David A. Mellis
// Date : 25 Oct, 2006
// Modified: 23 Mar 2010
// Version : 2.0
// Notes : Code for using a 74HC595 Shift Register //
// : Display specified value
//****************************************************************
//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;
void setup() {
//set pins to output so you can control the shift register
pinMode(latchPin, OUTPUT);
pinMode(clockPin, OUTPUT);
pinMode(dataPin, OUTPUT);
Serial.begin(9600);
Serial.println("reset");
}
void display(unsigned int numberToDisplay){
digitalWrite(latchPin, LOW);
shiftOut(dataPin, clockPin, MSBFIRST, numberToDisplay % 256); //lower byte
shiftOut(dataPin, clockPin, MSBFIRST, numberToDisplay / 256); // higher byte
digitalWrite(latchPin, HIGH);
display(43690);
}
I have read you right Mike Void (display) instead of Void (loop)?
No you always need a loop, you need the display as well, and you call it anywhere you want. Here I have put it in the setup();
//**************************************************************//
// Name : shiftOutCode, Hello World
// Author : Carlyn Maw,Tom Igoe, David A. Mellis
// Date : 25 Oct, 2006
// Modified: 23 Mar 2010
// Version : 2.0
// Notes : Code for using a 74HC595 Shift Register //
// : Display specified value
//****************************************************************
//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;
void setup() {
//set pins to output so you can control the shift register
pinMode(latchPin, OUTPUT);
pinMode(clockPin, OUTPUT);
pinMode(dataPin, OUTPUT);
Serial.begin(9600);
Serial.println("reset");
display(43690);
}
void loop(){
}
void display(unsigned int numberToDisplay){
digitalWrite(latchPin, LOW);
shiftOut(dataPin, clockPin, MSBFIRST, numberToDisplay % 256); //lower byte
shiftOut(dataPin, clockPin, MSBFIRST, numberToDisplay / 256); // higher byte
digitalWrite(latchPin, HIGH);
}