Quantcast
Channel: EngineerZone : Popular Discussions - MEMS Inertial Sensors
Viewing all articles
Browse latest Browse all 2623

Calibrating ADXL375

$
0
0

Hi, I have a ADXL375 accelerometer evaluation board which I've connected to an atmel board. I'm now able to configure the accelerometer as I want and read the acceleration. I've defined the Bandwidth = 800Hz and I'm reading X0 to Z1 at the same time. With the offset = 0 and Z at -1g and X and Y at 0g, I'm getting the following:

 

X0 = 64
X1 = 0
Y0 = 80
Y1 = 0
Z0 = 32
Z1 = 255

 

my sensitivity is 400/8192 = 0.048828125 g/LSB (~=49mg like the datasheet says).


So:

Xaccel = 64 * 0.049 = 3.136g
Yaccel = 80 * 0.049 = 3.92g
Zaccel = -224 * 0.049 = 10.976g

 

Well, like it says in the datasheet, 1g equals 20.5 LSB so it is not reasonable that I'm getting values >>>>>> 1g.

In the datasheet also says that the typical offset is 400mg ( offset ~= 0x02 for each axis because 1 LSB corresponds to 196 mg, right??) and if we look to the values I'm getting, it makes sense that my sensitivity should be 4.9mg so my values would be:

 

Xaccel = 0.3136

Yaccel = 0.392

(which would be ~0g with the 400mg of offset

and Zaccel = 1.0976g

 

Do you know what I'm doing wrong? Are the values that I'm getting normal or do they seem weird for you to?

 

Thanks in advance.


Viewing all articles
Browse latest Browse all 2623

Trending Articles