Replies to This Discussion

Permalink Reply by Mohd Abdul on January 6, 2011 at 1:32am

hi Gilles,

 

thank you for the code. I tested it and it works fine.

But, the yaw values are so weird. They keep changing from positive to negative values and vice versa although i did't touch the board. Do you know why? Hpw should i edit it?

I attached the screenshot for the error value2. Icircled it with red ink.

-Thanx in advance-

Attachments:

• error2.bmp, 2 MB

• ▶ Reply

Permalink Reply by GillesW on January 6, 2011 at 4:09pm

It is not a problem of changing sign, it is only a problem of normal "noise" on the yaw value, but occuring close to 180°.

And -180°=180°, so if yaw is yelding between 178 to 182°, it will look blinking between 178° and -178°.

 

Just turn the board, and check if you still have changinging sign (for instance around a yaw of 90°)

 

Gilles

 

• ▶ Reply

Permalink Reply by Mohd Abdul on January 7, 2011 at 3:33am

oh, you are right!! sorry.. =)

 

Any idea why the value is jumping gradually for yaw angle from 20° to 1++° although i didn't touch the board??

 

thanx again Gilles =)

Permalink Reply by GillesW on January 9, 2011 at 3:16pm

In your error2 file, it works ok.

 

In the previous error file, it was ko. I presume there is a bug in your program. You have the example of my prog that is working, so try to compare and identify the bug in yours.

It is impossible to imagine where does your bug come from.

 

But, did you check if your code correctly cancels DCM offsets with the magnetometer ?

 

Gilles

 

 

Permalink Reply by Karl Dall on February 14, 2011 at 3:18am

Hi there,

 

I have a short question. I'm trying to use your AHRS code with the 9DOF sensor stick of Sparkfun. I already changed the data acquisition (sensor stick has an ITG3200). Now, my problem is to figure out which axis directions you need for the algorithm. Should all the axis be aligned for the calculation? (ACC, Gyro and Mag). I only ask, because when looking at the picture of the 9DOF board on Sparkfun, it seems that the Gyro axis are reversed compared to the ACC, but where do you actually change the order?

 

Thanks in advance,

Martin

• ▶ Reply

Permalink Reply by Karl Dall on February 14, 2011 at 6:26am

Hi there,

 

I have to answer my own question ;). I found the corresponding lines in the source code and switched the values according to my setup. And now, the data looks very good. Roll and Pitch angle are almost independent (except a little influence ;) ). Last thing, I have to repair is the yaw angle. It is pretty much influenced by the other two angles. Can I repair that with the calculation? (maybe there is still something wrong with the Z-Axis alignment) Or is this behaviour more or less normal :) ?

 

Ah, forgot one point. Tried out the python GUI. It is really slow on my windows 7 machine? Anyone else got this? The output is at least 10 seconds delayed when tilting my frame....

 

Thanks in advance,

Martin

• ▶ Reply

• ‹ Previous
• 1
• …
• 3
• 4
• 5
• Next ›
• Page