#define cross_width 15
#define cross_height 15
-static char cross_bits[] = {
+static unsigned char cross_bits[] = {
0x84, 0x10, 0x84, 0x10, 0xff, 0x7f, 0x84, 0x10, 0x84, 0x10, 0x84, 0x10,
0x84, 0x10, 0xff, 0x7f, 0x84, 0x10, 0x84, 0x10, 0x84, 0x10, 0x84, 0x10,
0xff, 0x7f, 0x84, 0x10, 0x84, 0x10};