Wrong values on Self-test accelerometers (ADXL335)

Hello, i'm using an ADXL 335. I had weird values when i tried to get the static acceleration on the three differents axes. I have decided to try the Self-test pin by powering the Self-test pin with 3,6 V and 2 V.

I chose those two voltages because results for the Self-test are written in the datasheet for those voltage.

I have great result for 2 V (Ux=82mV, Uy= 98mV and Uz = -190mV)
Theorically i should have Ux = -96, Uy = 9- and Uz = -163.

BUt let's say it's okay

Now when it comes to 3,6V. Instead of having a diffence of voltage when Selftest is off and selftest is on of :
Ux = -560
Uy=560 mV
Uz = 950 mV

I have :
Ux = 150 mV
Uy= 149 mV
Uz = - 294 mV

something is not working and i don't know what. I tried the same experiment with two others ADXL 335 but it was the same problem.

Thank you for your time, hope you can help me :slight_smile:


Welcome to the forum.

Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html then look down to item #7 about how to post your code.
It will be formatted in a scrolling window that makes it easier to read.

Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

Have you got your X,Y and Z axes oriented correctly?

Tom.. :slight_smile:

Whats changed from your OTHER post on the same topic? (where you have answers?)