wipe full lines

game-ctrl/canvas.c

@@ -44,7 +44,8 @@ void canvasInit() {
   // between the both MCUs.
   // With 8 the transfer of a complete 110 pixel canvas takes
   // about 720us.
-  UCB0BR0 = 8; 
+  // 8 was still too fast and caused problems.
+  UCB0BR0 = 16; 
   UCB0BR1 = 0;
 
   // BIT5: UCB0CLK

game-ctrl/game.c

@@ -59,6 +59,12 @@ void gameExec(void *handle) {
   }
 
   canvasShow();
+  for (uint8_t r = 0; r < CANVAS_HEIGHT; r++) {
+    if (canvasIsRowFilled(r)) {
+      canvasWipeRow(r);
+      canvasShow();
+    }
+  }
 }
 
 void gameInit() {