Default pulse width and polarity dont work with DM9 Spektrum module

[GoogleCodeExporter]

Stock board
OpenTx v. 2751
EEprom 213-2

What steps will reproduce the problem?
1. Install Spektrum DM9 module
2. Switch on and try to bind
3. Bind does not work
4. Go to model setup
5. Change polarity from - to +
6. Bind works, servos are off center (output 1400 µs instead of 1500 µs)
7. Change pulse width from 300 to 400 µs
8. Servos center correctly

It is suggested to set the default values as:
polarity = +
pulse width = 400 µs

This will save DM9 users a lot of head scratching and make no difference to 
other users.

Original issue reported on code.google.com by piednoir...@gmail.com on 11 Sep 2013 at 9:08

[GoogleCodeExporter]

300- is a good standard for a lot of modules... (jeti, futaba, frsky)
So really no reason to change it as DM9 uses it's own one....
BTW a module should not change the center as pauses changes...
Please open an issue with horizon hobby, DM9 acts out of any reasonable 
standard.

Original comment by romolo.m...@gmail.com on 11 Sep 2013 at 9:19

• Changed state: Invalid

[GoogleCodeExporter]

400 �s is an equally good standard for a lot of modules and polarity
doesn't matter,
So, no good reason not to change it.
I'm not going to open an issue with Horizon Hobby because I don't really
have a problem, just trying to help others.

Best modelling regards.

Jean-Marie Piednoir

Original comment by piednoir...@gmail.com on 12 Sep 2013 at 5:51

[GoogleCodeExporter]

Horizon Hobby has badly implemented a CPPM decoder in their module and you are 
asking us a fix ??
So what about Futaba TM14 owner that require different length ?
We default to the most common one, specific needs can be adjusted by the user.

DM9 is not the most common one.

Definitively an invalid/wontfix issue.

Original comment by romolo.m...@gmail.com on 12 Sep 2013 at 6:26

[GoogleCodeExporter]

How much Horizon Hobby is ready to pay for us working in this?

;)

Original comment by bson...@gmail.com on 12 Sep 2013 at 6:51

[GoogleCodeExporter]

Okay, I get it.
Both Spektrum and Futaba have made a bad design and you've made a choice.
No problem with me since i am a dedicated FrSky user anyway.

Original comment by piednoir...@gmail.com on 12 Sep 2013 at 7:05

[GoogleCodeExporter]

I am a dedicated FrSky user anyway and don't care one way or another, just
tried to help others:
Spektrum users must suffer for their sins, I know, I know...
Original discussion on RC Groups:
http://www.rcgroups.com/forums/showpost.php?p=26083413&postcount=9907

Original comment by piednoir...@gmail.com on 12 Sep 2013 at 7:12

[GoogleCodeExporter]

Futaba has a good design, but TM14 requires a different standard length due to 
possible 14 channels.
Conversely spektrum modules assumes a fixed length for interpause and measure 
only raised part of the signal making a very stupid not standard implementation.
What about using a DM9 module in a graupner/jr radio that are at 300uSec 
interpause as well ?

That's not matter of spektum user to pay for their sins, but to do not say 
there is a defect on opentx/er9x while the defect is in DM9.

BTW people has two possibilities get the DM9 to work: adjust PPM interframe 
and/or PPM center.
On opentx side we have given the maximum of flexibility, so this is 
definitively a issue HH should solve and not us.

Original comment by romolo.m...@gmail.com on 12 Sep 2013 at 7:37

[GoogleCodeExporter]

Does anyone know what polarity and pulse width JR use in their radios? Is there 
a default setting that can be changed or do they use a fixed polarity/pulse 
width?

The reason I ask is because the Taranis is advertised as having a JR based 
module. If any company has more weight than the others, wouldn't it be JR?

Original comment by jcansd...@gmail.com on 12 Sep 2013 at 1:33