How to interpret accelerometer data to get decimals from -255 to 255
Use this code:



AcX = map(AcX, -32768, 32767, -255, 255);
AcY = map(AcY, -32768, 32767, -255, 255);


Of course, you won't be able to store the resulting value in int8_t since its range is from -128 to 127.

Here you can read more about Arduino map() function.