View Full Version : Accelerometer Problems

01-27-2009, 06:17 PM
We just got our accelerometer wired up and connected, however, it is not outputting any acceleration. We think our code should be functional, but if someone could post some working code so that we could test if the wiring is defective or not, then I would be very appreciative.

01-27-2009, 09:01 PM
There are several posts on correct wiring; search them out and look if the wiring is right first.
Or post how you wired it so we can check it.

01-28-2009, 03:04 PM
Here are some pictures of how it is wired, forgive me if they are bad angles/bad quality. Also, here is a rough diagram of how it is wired:


o o o (sig)
o o x (5v)
o o o (0v/ground)

Also, to expound on our problem, the only outputs we get are either constant negative numbers (ex: an unchanging -.983) or a sequence of bizzare negative numbers.

Alan Anderson
01-29-2009, 12:09 AM
Here are some pictures of how it is wired, forgive me if they are bad angles/bad quality. Also, here is a rough diagram of how it is wired:

That only shows us one end of the connection. What we really needed to know is where the other end of each of those wires is going.

01-29-2009, 02:54 PM
Here are some picture of the accelerometer connected to the analog module, as requested. Sorry in advance again if these are low quality/insufficient.

01-29-2009, 04:19 PM
Sorry to double post, but we resolved the problem. It seemed that we needed to scale the accelerometer drasticly to have any useful value.

Alan Anderson
01-29-2009, 04:26 PM
I hope you merely unplugged the 12 volt supply from that analog breakout's power connector so you could get a good photo of the sensor cables...

...but in case that's an accurate picture of how your control system looks when you're running it, the missing power connection explains your problem perfectly. The 12 volt input to the breakout is used to generate the 5 volts to power the accelerometer.

Just so we're clear on this, the tiny green LED on the analog breakout board needs to light up when you power up the control system. If it doesn't, you're not providing power to the sensors.

01-29-2009, 04:59 PM
I use this VI to test accelerometer wiring. It isn't ready for prime time, so please excuse any messiness. If someone wants to pretty it up and repost it, I'd be eternally grateful for at least a week.

It does silly things like assume everything is plugged into the first bumper, and I haven't figured out how to get the time to display on the waveform chart properly yet. I'm still learning this labview thing.

Add miswiring indicators (alert! Y axis is unplugged!)
Add out of spec indicators (alert! you are on the moon!)
Prettify it.