Saturday, May 23, 2015

Improving Barometer Altitude Detection on APM_252 - Quanum Nova FC case Mod

I've seen some Cheerson CX-20 Flight-Controller cases with large holes over barometer (but still has gray foam inside). Compared to those, my Quanum Nova one is being suffocated :) It might not be able to detect atmospheric as well, or might be adversely affected by circuit board heat.

Anyway, I did this simple mod. I just removed top cover and drilled a 3/16" hole through it, near where the barometer sensor is.

 
 
 It already seems to be working better while on bench and floor (more accurate and less drift while at rest).


  

 NOTE 2015-06 : Ever since I did this mod, my Barometer seems to be "drifting" more (not holding, even while sitting on desk). Not sure if I'm just paying more attention to an existing problem, or if it actually caused the problem. In flight, my Altitude-Hold Mode also drifts or holds poorly. At this time, I would not recommend this mod. I put some packing tape over new hole to block 80% of opening. It's back to normal now. It works better outside than inside, but that's ok.

2 comments:

  1. Dang, too bad this didn't help even a little bit. The barometer seems to be one of the weaker links of the position fix elements, since weather can have drastic effects on barometric pressure.

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    1. Agreed. I don't think mine works very well, but I'm stuck with it since it's soldered onto the board (other than replacing whole FC). I can see altitude drifting during pre-flight checks (inside or outside). 95% sure this is why it auto-lands poorly (or poorly detects an actual landing) ... it doesn't know where 0 meters is.

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