# 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

Anthony

Hi,
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..

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