Hi,

I am trying to make sense of the results I had with the ADXL362. The accelerometer is built on a platform that we can access via Bluetooth. I can send commands from a phone to read X, Y, Z registers, respectively at the address 0x08, 0x09 and 0x0A.

I did orientation testing based on the datasheet on page 42. The test cases are listed on the picture with the orientation (little dot).

I am reading the 8-bit value for each axis, the values below are in decimal. The measurement range is +-2g, sensitivity: 1mg/LSB, scale factor 1000 LSB/g

Case 1: X: 63 - Y: 249 - Z: 7

Case 2: X: 249 - Y: 64 - Z: 16

Case 3: X:179 - Y: 246 - Z: 14

Case 4: X:255 - Y: 180 - Z: 11

Case 5: X:249 - Y: 246 - Z: 198

Case 6: X:248 - Y: 249 - Z: 77

I am trying to make sense of the data read above and would like to map the result to the data on the picture below. Here are couple of questions:

1) If the 0G is the mid-range @127 (decimal), I can understand 63 (-1g), I am not able to make a sense of Y and Z value, could you help me?

2) Do I need to subtract the reference (127) from the result? to find the number of g?

Help would be very welcome.

Thanks,

Hello Odyssey,

the data is given in twos-complement format.

Two's complement - Wikipedia, the free encyclopedia

You do not have to subtract 127, but you have to be aware, that all numbers bigger than 127 are in fact negative numbers. (255 means -1, 254 means -2, ...).

So your results in decimal are as follows:

So the numbers fit to the drawing in the datasheet of ADXL362 (in your appended drawing you have inverted the signs of x and y).