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115 lines
2.9 KiB
Plaintext
115 lines
2.9 KiB
Plaintext
/*
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Row-Column Scanning an 8x8 LED matrix with X-Y input
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This example controls an 8x8 LED matrix using two analog inputs
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created 27 May 2009
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modified 4 Sep 2010
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by Tom Igoe
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This example works for the Lumex LDM-24488NI Matrix. See
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http://sigma.octopart.com/140413/datasheet/Lumex-LDM-24488NI.pdf
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for the pin connections
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For other LED cathode column matrixes, you should only need to change
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the pin numbers in the row[] and column[] arrays
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rows are the anodes
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cols are the cathodes
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---------
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Pin numbers:
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Matrix:
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* Digital pins 2 through 13,
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* analog pins 2 through 5 used as digital 16 through 19
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Potentiometers:
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* center pins are attached to analog pins 0 and 1, respectively
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* side pins attached to +5V and ground, respectively.
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This example code is in the public domain.
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http://www.arduino.cc/en/Tutorial/RowColumnScanning
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see also http://www.tigoe.net/pcomp/code/category/arduinowiring/514 for more
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*/
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// 2-dimensional array of row pin numbers:
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const int row[8] = {
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2,7,19,5,13,18,12,16 };
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// 2-dimensional array of column pin numbers:
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const int col[8] = {
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6,11,10,3,17,4,8,9 };
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// 2-dimensional array of pixels:
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int pixels[8][8];
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// cursor position:
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int x = 5;
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int y = 5;
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void setup() {
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Serial.begin(9600);
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// initialize the I/O pins as outputs:
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// iterate over the pins:
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for (int thisPin = 0; thisPin < 8; thisPin++) {
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// initialize the output pins:
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pinMode(col[thisPin], OUTPUT);
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pinMode(row[thisPin], OUTPUT);
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// take the col pins (i.e. the cathodes) high to ensure that
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// the LEDS are off:
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digitalWrite(col[thisPin], HIGH);
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}
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// initialize the pixel matrix:
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for (int x = 0; x < 8; x++) {
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for (int y = 0; y < 8; y++) {
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pixels[x][y] = HIGH;
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}
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}
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}
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void loop() {
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// read input:
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readSensors();
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// draw the screen:
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refreshScreen();
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}
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void readSensors() {
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// turn off the last position:
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pixels[x][y] = HIGH;
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// read the sensors for X and Y values:
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x = 7 - map(analogRead(A0), 0, 1023, 0, 7);
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y = map(analogRead(A1), 0, 1023, 0, 7);
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// set the new pixel position low so that the LED will turn on
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// in the next screen refresh:
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pixels[x][y] = LOW;
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}
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void refreshScreen() {
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// iterate over the rows (anodes):
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for (int thisRow = 0; thisRow < 8; thisRow++) {
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// take the row pin (anode) high:
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digitalWrite(row[thisRow], HIGH);
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// iterate over the cols (cathodes):
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for (int thisCol = 0; thisCol < 8; thisCol++) {
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// get the state of the current pixel;
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int thisPixel = pixels[thisRow][thisCol];
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// when the row is HIGH and the col is LOW,
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// the LED where they meet turns on:
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digitalWrite(col[thisCol], thisPixel);
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// turn the pixel off:
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if (thisPixel == LOW) {
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digitalWrite(col[thisCol], HIGH);
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}
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}
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// take the row pin low to turn off the whole row:
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digitalWrite(row[thisRow], LOW);
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}
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}
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