I2C_DEBUG
I2C_DEBUG(printf("."));
I2C_DEBUG(printf("*"));
I2C_DEBUG(printf("! "));
I2C_DEBUG(printf("%c ", noack ? '-' : '+'));
I2C_DEBUG(printf("w!"));
I2C_DEBUG(printf("w%02x", data));
I2C_DEBUG(printf("r! "));
I2C_DEBUG(printf("r%02x%c ", *data, last ? '-' : '+'));
I2C_DEBUG(printf("<<"));
I2C_DEBUG(printf("C!\n"));
I2C_DEBUG(printf("<"));
I2C_DEBUG(printf("D!\n"));
I2C_DEBUG(printf("%s>>", err != 0 ? "!" : ""));
I2C_DEBUG(printf("\n"));