saved 46 bytes by making some literal modulo operands explicitly unsigned

animations/bitmapscroller.c

@@ -150,11 +150,11 @@ static void bitmap_recalculateVector(bitmap_t const *const pBitmap,
 {
 	if (((x + *pdx) > (pBitmap->nXDomain)) || ((x + *pdx) < 0))
 	{
-		*pdx = random8() % 2 * (x < (pBitmap->nXDomain / 2) ? 1 : -1);
+		*pdx = random8() % 2u * (x < (pBitmap->nXDomain / 2) ? 1 : -1);
 	}
 	if (((y + *pdy) > (pBitmap->nYDomain)) || ((y + *pdy) < 0))
 	{
-		*pdy = random8() % 2 * (y < (pBitmap->nYDomain / 2) ? 1 : -1);
+		*pdy = random8() % 2u * (y < (pBitmap->nYDomain / 2) ? 1 : -1);
 	}
 	if (*pdx == 0 && *pdy == 0)
 	{

games/snake/snake_game.c

@@ -27,7 +27,7 @@ game_descriptor_t snake_game_descriptor __attribute__((section(".game_descriptor
 #define SNAKE_NEWCONTROL
 
 // limits
-#define SNAKE_MAX_LENGTH 64
+#define SNAKE_MAX_LENGTH 64u
 #define SNAKE_MAX_APPLES 10
 
 // delays (in milliseconds)
@@ -194,7 +194,7 @@ static void snake_userControl(snake_protagonist_t *pprotSnake,
 		{
 			// rotate through directions (either clockwise or counterclockwise)
 			pprotSnake->dir = (pprotSnake->dir +
-					(dirJoystick == SNAKE_DIR_LEFT ? 3 : 1)) % 4;
+					(dirJoystick == SNAKE_DIR_LEFT ? 3 : 1)) % 4u;
 		}
 	}
 	*pdirLast = dirJoystick;
@@ -273,7 +273,7 @@ static void snake_autoRoute(snake_protagonist_t *pprotSnake,
 					return;
 				}
 			}
-			pprotSnake->dir = (pprotSnake->dir + 1) % 4;
+			pprotSnake->dir = (pprotSnake->dir + 1) % 4u;
 		}
 		else
 		{

pixel.h

@@ -60,7 +60,7 @@ inline static unsigned char get_next_pixel(pixel p, direction_t dir){
 
 
 inline static direction_t direction_r(direction_t dir){
-	return (dir + 1) % 4;
+	return (dir + 1) % 4u;
 }