Closed GoogleCodeExporter closed 8 years ago
use ppm center adjustable option...
Original comment by romolo.m...@gmail.com
on 11 Sep 2013 at 8:10
PPM center can be set up to the microsecond using PPMCA option
PPM center is not intended to be adjusted using PPM interframe.
Original comment by romolo.m...@gmail.com
on 11 Sep 2013 at 8:13
Where is the PPM center option? I couldn't find it on the 'MODEL SETUP' menu.
Original comment by jcansd...@gmail.com
on 11 Sep 2013 at 9:41
In limits (last column) by default is 1500
But please open an issue also with horizon hobby.
There is absolutely no reason for having the center conditioned by interpulse
pause...
That's a very bad implementation of a PPM decoder.
Original comment by romolo.m...@gmail.com
on 11 Sep 2013 at 9:54
Oh, you're suggesting changing the center by the same amount for every servo?
This feels like more of a hack than having finer control over the PPM frame
pulse width. What's the point of being able to change the pulse width if we
can't set it to what the module expects?
I realise it's probably a bad implementation of a PPM decoder, but there are a
lot of these modules in the wild already. If people want to move over to OpenTx
from a Spectrum radio, this is the module they will probably use unless they
want to risk the Orange one (which has very mixed reviews). AFAIK it works okay
in JR radios.
I'm sure Horizon will be more interested in selling their new DX9 radio than
fixing the DM9 so that people can easily use it in the Taranis. ;)
Original comment by jcansd...@gmail.com
on 11 Sep 2013 at 10:39
Yes it is a hack , but so would be implementing strange pulse lengths... The
PPM pulse length is supposed to be insignificant in the first place! A module
should not depend on it at all, and even less change servo positions according
to it!
All users so far seem to be happy with positive modulation and 400us PPM pulse.
A model that is ported from another radio to the Taranis will likely require
mechanical readjustment anyway due to different center points and throws
between radios and firmwares.
Original comment by bernet.a...@gmail.com
on 12 Sep 2013 at 1:49
I've investigated this further and a 400us PPM pulse with the DM9 does give a
servo centre position of 1.5ms. The dependency appears to be with my DX8, which
is showing a centre position of 1.52ms! :( I've asked on the DX8 forum about
this.
The reason I'm interested is because I've been wondering about writing a DX8 ->
OpenTx model conversion tool. I don't know how feasible this might be.
Original comment by jcansd...@gmail.com
on 12 Sep 2013 at 9:01
Reply on RCGroups from spectrum66:
http://www.rcgroups.com/forums/showpost.php?p=26092142&postcount=10019
That's simple:
servo center standard pulse width is just a convention:
some producer use 1500, some 1520, some other 1620
That's why in Limits opentx offers the possibility to set the center per
channel.
Then there is the issue with DM9 module.
That module has a programming issue: it only measure pulse width considering
interpause fixed at 400uSec instead of measuring time between two leading
edges.
So if you want 1520 with a DM8 you need to set interpause at 400uSec and in
channel limit set PPM center at 1520, that's all.
That said, you cannot ask opentx to change actual interpause or center pulse
timing defaults as another radio performs differently...
We cannot force a lot of users to readjust centers just to conform to a single
producer standard.
Romolo
Original comment by jcansd...@gmail.com
on 12 Sep 2013 at 9:31
LOL, it was you. Thanks for your help and explanations! :)
Original comment by jcansd...@gmail.com
on 12 Sep 2013 at 9:33
[deleted comment]
Original comment by bson...@gmail.com
on 29 Nov 2013 at 8:58
Original comment by bson...@gmail.com
on 29 Nov 2013 at 8:58
Original issue reported on code.google.com by
jcansd...@gmail.com
on 11 Sep 2013 at 8:06