Accelerometer from modern device alright?

Forum 2005-2010 (read only) Hardware Interfacing
1

I'm shopping for an accelerometer and I found this one:
http://shop.moderndevice.com/products/mma7260qt-3-axis-accelerometer

Does anyone have experience with this item? Any problems with Arduino? Thanks.

2

OK just bought one. Will report back when I get it in the mail and test it out. Seems to be the cheapest accelerometer I've come across.

3

There're terrible! Draws over 10A and you need to put it in a rocket to get a reading. Oh, I see you bought it already. :wink:

In that case, I'll say I'm very happy with mine. It works great. ModernDevice did a great job in breaking out the pins and providing a 3.3V reg. Great price too. Enjoy.

4

So besides a rocket engine, and slight current draw, it outputs ratiometric output centered around 1.65V, right? ;D

5

Yep, centered around VCC so if you run the Arduino at 5V, run a line to ARef and set it EXTERNAL.

Forget about the 10A bit - I accidentily had it wired in series with my toaster.

6

Yep, centered around VCC so if you run the Arduino at 5V, run a line to ARef and set it EXTERNAL.

Why do that? Normal Arduino A/D reference is using the voltage wired to the AVcc pin, which is also the same +5vdc voltage that the Vcc pin uses.

Lefty

7

I gues I should have said Yep, "centered around VCC of the accelerometer" - which is running on 3.3V max. So if the Arduino is running on 5V, Aref will be based on 5V and you loose precision right?

So by using the VCC (from the accelerometer) (and not even the FTDI) you get the best precision. Am I missing something ?