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Topic: Binary counter with 16 Leds (Read 1 time)previous topic - next topic

JimiH

Feb 27, 2011, 04:41 pmLast Edit: Feb 27, 2011, 04:43 pm by JimiH Reason: 1
Hello

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?

Code: [Select]
`//**************************************************************////  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 74HC595int latchPin = 8;//Pin connected to SH_CP of 74HC595int clockPin = 12;////Pin connected to DS of 74HC595int 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

Geoff

robtillaart

#1
Feb 27, 2011, 06:23 pm
use  unsigned int  iso  int as it can go to 65535 = 1111 ...1 (16x)

- http://www.arduino.cc/en/Reference/UnsignedInt
Rob Tillaart

Nederlandse sectie - http://arduino.cc/forum/index.php/board,77.0.html -
(Please do not PM for private consultancy)

JimiH

#2
Feb 27, 2011, 07:14 pm
Thanks that looks like what I need. Any example of how i would incorporate this into the shiftout code?
Code: [Select]
`//**************************************************************////  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 74HC595int latchPin = 8;//Pin connected to SH_CP of 74HC595int clockPin = 12;////Pin connected to DS of 74HC595int 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);  }}`

regards

Geoff

robtillaart

#3
Feb 27, 2011, 08:17 pm
Read - http://www.arduino.cc/en/Tutorial/ShiftOut - carefully especially the part about red /green leds at the end.

The code should be something like below (not tested)
Code: [Select]
`void loop(){  for (unsigned int numberToDisplay = 0;  ; numberToDisplay++)  // it will automagically wrap around ..  {    digitalWrite(latchPin, LOW);    shiftOut(dataPin, clockPin, MSBFIRST, numberToDisplay % 256);  lower byte    shiftOut(dataPin, clockPin, MSBFIRST, numberToDisplay / 256);  higher byte    digitalWrite(latchPin, HIGH);    delay(500);  }}`
be aware 65535 * 500 millisec = 32767 seconds, thats about 9 hours for one loop...
Rob Tillaart

Nederlandse sectie - http://arduino.cc/forum/index.php/board,77.0.html -
(Please do not PM for private consultancy)

JimiH

#4
Feb 27, 2011, 11:27 pm
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)?

Regards

Geoff

Grumpy_Mike

#5
Feb 28, 2011, 12:04 am
Code: [Select]
`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);}// then use   display(43690);`

JimiH

#6
Feb 28, 2011, 10:11 pm
Thanks Mike I'll give that a go.

Geoff

JimiH

#7
Feb 28, 2011, 10:31 pm
Wow this doesn't want to go in??

I keep getting a
Code: [Select]
`"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)?
Code: [Select]
`//**************************************************************////  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 74HC595int latchPin = 8;//Pin connected to SH_CP of 74HC595int clockPin = 12;////Pin connected to DS of 74HC595int 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);}`

Thanks

Geoff

Grumpy_Mike

#8
Feb 28, 2011, 11:46 pm
Quote

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();

Code: [Select]
`//**************************************************************////  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 74HC595int latchPin = 8;//Pin connected to SH_CP of 74HC595int clockPin = 12;////Pin connected to DS of 74HC595int 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);}`

JimiH

#9
Mar 01, 2011, 12:24 am
Thanks Mike, still learning only had it a week

Geoff

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