remcoder · September 23, 2016 12:02 · Jul 16, 2013 · Jul 16, 2013 · Jul 16, 2013
diff --git a/game of life with 8x8 bicolor led matrix b/game of life with 8x8 bicolor led matrix
@@ -1,3 +1,17 @@
+/*
+I recently got one of those 8x8 LED matrices  and I was playing with some Game of Life patterns when I found this pretty repeating pattern. I found it by starting with some random patterns. If you look closely you can see the pattern becoming a mirrored version of itself halfway through. Apparently the pattern doesn't repeat like this on an infinite grid but on this wrapping 8x8 grid it does ;-) 
+
+FYI, the LED matrix is a bicolor one (green/red) and has an I2C interface (http://www.adafruit.com/products/902). I'm using the colors as follows:
+ - newly created cells are green
+ - cells that are at least 10 generations old are red
+ - other living cells are yellow (simultaneously green+red)
+
+It's hookup up to my Arduino Uno r3.
+
+here's a video: http://www.youtube.com/watch?v=Ee2hOaQ2RDI
+
+*/
+
 #include <Wire.h>
 #include "Adafruit_LEDBackpack.h"
 #include "Adafruit_GFX.h"

diff --git a/game of life with 8x8 bicolor led matrix b/game of life with 8x8 bicolor led matrix
@@ -1,4 +1,3 @@
-
 #include <Wire.h>
 #include "Adafruit_LEDBackpack.h"
 #include "Adafruit_GFX.h"

diff --git a/game of life with 8x8 bicolor led matrix b/game of life with 8x8 bicolor led matrix
@@ -0,0 +1,96 @@
+
+#include <Wire.h>
+#include "Adafruit_LEDBackpack.h"
+#include "Adafruit_GFX.h"
+
+boolean cells[8][8];
+
+Adafruit_BicolorMatrix matrix = Adafruit_BicolorMatrix();
+
+// game of life
+int next[8][8];
+
+void setup() {
+  Serial.begin(9600);
+  Serial.write("hello");
+
+  randomSeed(analogRead(0));
+  for (int r=0 ; r<8 ; r++) {
+    for (int c=0 ; c<8 ; c++) {    
+      if (random(2) >0)
+        next[r][c] = 1;
+    }
+ } 
+
+  matrix.begin(0x70);  // pass in the address
+}
+
+void loop() {
+
+  game_of_life();
+}
+
+int current[8][8] =
+{ {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,1,1,1,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0} };
+
+int mod(int a) { return (a+8)%8; }
+
+void game_of_life() {
+
+  matrix.clear();
+
+  // draw
+  for (int r=0 ; r<8 ; r++) {
+    for (int c=0 ; c<8 ; c++) {
+      int color;
+      if (next[r][c] == 0)
+        color = 0;
+      else if (next[r][c] == 1) 
+        color = LED_GREEN;
+      else if (next[r][c] > 10)
+        color = LED_RED;
+      else
+        color = LED_YELLOW;
+      matrix.drawPixel(c,r,color);
+    }
+  }
+  matrix.writeDisplay();
+
+  // calc next state
+  for (int r=0 ; r<8 ; r++) {
+    for (int c=0 ; c<8 ; c++) {    
+      // count alive neighbors
+      int alive = 0;
+      alive += current[mod(r+1)][mod(c)  ] != 0;
+      alive += current[mod(r)  ][mod(c+1)] != 0;
+      alive += current[mod(r-1)][mod(c)  ] != 0;
+      alive += current[mod(r)  ][mod(c-1)] != 0;
+      alive += current[mod(r+1)][mod(c+1)] != 0;
+      alive += current[mod(r-1)][mod(c-1)] != 0;
+      alive += current[mod(r+1)][mod(c-1)] != 0;
+      alive += current[mod(r-1)][mod(c+1)] != 0;
+      if (current[r][c])
+        if (alive < 2 || alive > 3)
+          next[r][c] = 0;
+        else
+          next[r][c] = current[r][c] + 1;
+      else
+        if (alive == 3)
+          next[r][c] = 1;
+    }
+  }    
+
+  for (int r=0 ; r<8 ; r++) {
+    for (int c=0 ; c<8 ; c++) {    
+      current[r][c] = next[r][c];
+    }
+  }  
+  delay(100);
+}