SparkFun Forums

[Gilmer]

Hello

We've bought the Atomic IMU - 6 Degrees of Freedom XBee Ready
(http://www.sparkfun.com/commerce/produc ... ts_id=9184)
and the USB conector. I've installed the drivers and the Atomic Mixer for tests.

First thing we noticed is that the bars of the Atomic Mixer is inverted, in the acceleration values, the bars represent the axis, and the axis bars represents the acceleration. Problably a simple mistake in coding.

Right after, we noticed that the Z axis (Yaw) did not seems to work. We intend to use the IMU for head tracking, so the most important is to track the head turning left or right.

Illustration of the problem:




can someone give an explanation of what is happening. How can we fix this and get the true values of the Z axis?

[mcfly24]

I hace a Atomic IMU 6DOF, SEN-09184 connected with Xb24 and XBee Explorer USB (WRL-08687) connected with Xb24.
I have X-CTU sofeware and use "Remote Configuration" to config ( Network & security, RF interface, Serial interface....). Then i use Range Test in X-CTU and try to sent data from XBee Explorer USB to SEN-09184 but SEN-09184 can't reveive it.
In the similar way, if i replace SEN-09184 by XBee Explorer Serial (WRL-09111) eveything is ok
Please help me to make it throught.
Thanks and waitting for your replay!!!

[oni]

I have exactly the same problem. I posted here which is naughty of me I guess:
viewtopic.php?f=14&t=28456

Did you solve this? Its EXACTLY what Im getting and I also want to use this board for head-tracking!

Actually, its not exactly the same because I use the XBee connection, not the UART one but nevertheless, identical results.

[rrosa]

i checked the sensors, and they seem to be working, the analog output from each gyro gets to the atmega.
if you tilt it around, you'll find the yaw rotating around some weird composition of pitch and roll.
i'd go for something wrong in the atmega code...

still looking into that.

[oni]

Sorry, this was my fault. I was thinking about gyros incorrectly. Turns out the board is fine and working perfectly. I fell victim to the misconception that Gyros measure absolute angles as oppose to force acting on them, therefore I was misleading myself. i think i've got it sussed now. Cheers!

[rrosa]

i was doing stupid stuff with the data. seems to work ok.

i'm currently working on my final project for my university in Uruguay, with 3 others.

i've adapted some code available for the 9dof to work on the Atomic IMU
i'm still working on it, so no guarantees yet, though seems to work pretty nice

link:
https://github.com/rlrosa/uquad/wiki/ImuDisplay

the wiki is in spanish, but the code has a lot of comments in english.
feel free to ask about whatever is not clear.

hope it helps

[rdoume]

Hi Rrosa,

Is your code for display works only on linux? I can't use it on windows ( with VPython ). Maybe I'm doing something wrong.

And, I have the same problem for yaw angle. I've got the right pitch and yaw, but I do not know how to get the good yaw.

[rdoume]

Hi rrosa,

Is your soft for display can work with Windows?
How did you manage to get the yaw value ?

Thanks

RD

[rrosa]

i did not test the software with windows, but i adapted it from a windows program for the 9dof, so it should be really easy to get to work on windows.

what problem are you getting with it on windows?
who complains? vpython or the serial part?

what are you getting on the yaw?
something horrible or simply a drift?

[rdoume]

My problems are in the serial part, but it's understandable because serial in linux and windows are different.

And for the yaw, i've got something very stange, totally different from what i'm supposed to get.

[rrosa]

did you try to open the port using a name such as "\\.\COMxx" ?
what error do you get?

[rdoume]

I did.

But when running, the program told me " Unable to open //.COM5 ".
I tried also "COM5" or ////./COM5 and everything i can found on the internet.

[rrosa]

you tried with the slashes the correct way, right? (on win use \, not /)

your're probably missing some driver
what are you using to connect to the imu?
an ftdi chip?