These are chat archives for PX4/Hardware

9th
Mar 2016
Chris Evans
@ChrisE-UoN
Mar 09 2016 11:53
I have some questions about the PX4FMU v3 REV_D which is available on the PX4/Hardware repo. The PCB which measures 30x30mm seems to be perfect for my PX4 Micro-Quad project.
  1. Has anybody fabricated the PCB design included in the repo?
  2. Have the board designs been adequately and thoroughly tested?
  3. Is the board available for purchase?
Andreas Daniel Antener
@AndreasAntener
Mar 09 2016 12:28
@kd0aij where did you mount the tube from the static port in your tests?
baro alt looks good :smile:
Mark Whitehorn
@kd0aij
Mar 09 2016 13:43
It's just a vertical nylon tube, about 3mm o.d. Results should be improved for a "T" shape with top and bottom ports.
https://goo.gl/photos/9Wa1MLfX9KvW7PZm8
Andreas Daniel Antener
@AndreasAntener
Mar 09 2016 14:04
thanks. yeah T shape could be interesting. Didn't you also try a disk shaped port like 3DR was experimenting with?
Mark Whitehorn
@kd0aij
Mar 09 2016 14:11
I tried a ping-pong ball with 4 circumferential ports and a pitot/static probe in various locations. None were any better than this vertical tube. On my racing quad, I'm finding that a static port directly on the pixracer case performs well for ALTCTL; and that the altitude readings from a small GPS module are useless.
Andreas Daniel Antener
@AndreasAntener
Mar 09 2016 15:11
how is it with pixracer i2c, external mag plus airspeed at the moment on master?
seems like when we hook everything up we can't get both mags to work
Mark Whitehorn
@kd0aij
Mar 09 2016 15:12
does it work OK without the airspeed sensor?
Andreas Daniel Antener
@AndreasAntener
Mar 09 2016 15:15
nope
we don't see IDs for internal and external mag
is that working for you? just pixracer with gps and external mag?
(standard 3dr gps module)
Mark Whitehorn
@kd0aij
Mar 09 2016 15:19
yes, I've been flying with a non-3DR external mag/gps, and I can change rc.sensors to make any of external, 9250 or 5883 the primary mag. (with recalibration required each time you change it, unfortunately)
Andreas Daniel Antener
@AndreasAntener
Mar 09 2016 15:21
ok we're checking the wiring again
Phillip Kocmoud
@pkocmoud
Mar 09 2016 15:22
If you have old cables, they might be pinned out backwards.
the first 100 sets were this way.
Andreas Daniel Antener
@AndreasAntener
Mar 09 2016 15:23
yeah, we had to change them, question is if we made a mistake changing them ;)
but it seems we got the calibration working on stable
Phillip Kocmoud
@pkocmoud
Mar 09 2016 15:23
Do you have the correction doc?
Then cabling is not your problem.
Andreas Daniel Antener
@AndreasAntener
Mar 09 2016 16:25
well we got it to work on stable. switching back to master everything worked. after re-calibrating with master it complained about too big offsets on the internal mag. after a reboot it was happy though
Mark Whitehorn
@kd0aij
Mar 09 2016 16:26
it probably didn't save your new calibration parameters
Andreas Daniel Antener
@AndreasAntener
Mar 09 2016 16:26
is this an issue? so we're still not sure if there might be an issue hidden in master
oh, good point
so we probably never had a chance on master even calibrating the external one?
Mark Whitehorn
@kd0aij
Mar 09 2016 16:28
the external mag should have low offsets and easily pass the cal test
Andreas Daniel Antener
@AndreasAntener
Mar 09 2016 16:28
right, but if the internal failed, would it have written the params for the external one?
Mark Whitehorn
@kd0aij
Mar 09 2016 16:28
OTOH, the internal mag could easily be seeing hard iron effects on the order of the earth field magnitude
I didn't write that firmware, and would probably have a hard time figuring out what it does by inspection :)
It would help a lot if the intended behavior were clearly documented. Most of the time I have to ask "Is that a bug or a feature?"
Andreas Daniel Antener
@AndreasAntener
Mar 09 2016 16:33
hehe, you know I'm sometimes tooo busy to check in the code my self (or lazy ;))
yes
Mark Whitehorn
@kd0aij
Mar 09 2016 16:35
I just changed the offset length limit from 0.6 to 24 :)
gauss
Phillip Kocmoud
@pkocmoud
Mar 09 2016 16:40
It would be great if there was an easy way to disable sensors or set the priority of sensors.
Disable the onboard mag, no problem, uncheck it??? or similar.