Stap 3: Code
//8x8 LED matrix row and column PINs const int ROWS[8] = {52, 42, 53, 46, 39, 51, 41, 47}; const int COLUMNS[8] = {44, 43, 45, 50, 49, 48, 40, 38}; //button PINs const int RANDOMIZE_BUTTON = 8; const int START_BUTTON = 9;
//gloabal variables bool started = false; bool field[8][8] = {}; bool nextField[8][8] = {}; unsigned long lastMillis = 0; void setup() { // setup all PINs for (int i = 0; i < 8; i++) { pinMode(ROWS[i], OUTPUT); pinMode(COLUMNS[i], OUTPUT); } pinMode(RANDOMIZE_BUTTON, INPUT); pinMode(START_BUTTON, INPUT); } void loop() { //read button states int randomizeButton = digitalRead(RANDOMIZE_BUTTON); int startButton = digitalRead(START_BUTTON); if (randomizeButton) {// stops and sets a random field started = false; for (int i = 0; i < 8; i++) { for (int j = 0; j < 8; j++) { field[i][j] = random(2); } } delay(200); } else if (startButton) {// starts or stops the iterations started = !started; delay(200); } else if (started) { //calculate next field if (millis() - 1000 > lastMillis) { //delay each iteration by 1000 milliseconds fillNextField(); for (int y = 0; y < 8; y++) { for (int x = 0; x < 8; x++) { field[y][x] = nextField[y][x]; } } lastMillis = millis(); } } //refresh the 8x8 LED matrix refreshScreen(); } //calculates the state of the next iteration void fillNextField() { for (int y = 0; y < 8; y++) { for (int x = 0; x < 8; x++) { nextField[y][x] = getCellsNextState(x, y); } } } //returns the cell's next state, true if alive, false otherwise bool getCellsNextState(int x, int y) { bool shouldBeAlive = false; shouldBeAlive |= (!field[y][x] && countAliveNeighbours(x, y) == 3); shouldBeAlive |= (field[y][x] && countAliveNeighbours(x, y) == 3); shouldBeAlive |= (field[y][x] && countAliveNeighbours(x, y) == 2); return shouldBeAlive; } // counts the alive neighbours this step int countAliveNeighbours(int x, int y) { int retVal = 0; for (int row = y - 1; row <= y + 1; row++) { for (int col = x - 1; col <= x + 1; col++) { if ((row == y && col == x) || (row < 0) || (row > 7) || (col < 0) || (col > 7)) continue; if (field[row][col]) retVal++; } } return retVal; } //refreshes the 8x8 LED matrix void refreshScreen() { // iterate over the rows (anodes): for (int row = 0; row < 8; row++) { // take the row pin (anode) high: digitalWrite(ROWS[row], HIGH); // iterate over the cols (cathodes): for (int col = 0; col < 8; col++) { // get the state of the current pixel; int thisPixel = field[row][col]; // when the row is HIGH and the col is LOW, // the LED where they meet turns on: digitalWrite(COLUMNS[col], thisPixel ? LOW : HIGH); // turn the pixel off: if (thisPixel) { digitalWrite(COLUMNS[col], HIGH); } } // take the row pin low to turn off the whole row: digitalWrite(ROWS[row], LOW); } }
