Posted on March 20, 2014 at 15:26Hello,
I'm trying to work with LIS3DSH device with different ranges.
I put the device on a table facing up, so Z axis should give me 1000mg reading, for all ranges.
I configure the device to range 2g by writing to reg_5 0x00
The raw value I got was 0x3ffe.
The sensitivity for this range is 0.06mg/digit according to spec,
So calculation is: 0x3ffe * 0.06 = 982.92 mg , close enough to 1000mg.
I flipped the device to measure negative value.
The raw value I got was 0xc001. according to spec I calculated 2's compelemt:
0xc001 -> 2's complement -> 0x3fff
So calculation is: (-1) * 0x3fff * 0.06 = -982.98 mg , close enough to -1000mg.
Then I tried to change range to 4g by writing to reg_5 0x08 (flipped the device back).
The raw value I got was very similar to the previous one 0x4002.
The sensitivity for this range is 0.12mg/digit according to spec,
So calculation is: 0x4002 * 0.12 = 1996.32 mg, almost 2000mg, not 1000mg!
What am I doing wrong here?
