LibrePilot Forum

Development => Firmware General => Topic started by: sz on May 30, 2016, 10:10:35 am

Title: PPM not recognized, frame to short
Post by: sz on May 30, 2016, 10:10:35 am
Hello,
I'm using ULRS for my RC models. With ULRS 2.x (http://www.itluxembourg.lu/site/ultimate-lrs-the-next-release/) LP doesn't recognize the PPM signal. Probably because (http://www.rcgroups.com/forums/showthread.php?t=2037442&page=251&highlight=cc3d#post33928817) of a short frame end of just 3ms. Ardupilot has no problem.
Is there maybe a way to get LP to work with ULRS? Would a feature request or issue be reasonable?
Thanks,
Sebastian
Title: Re: PPM not recognized, frame to short
Post by: f5soh on May 30, 2016, 11:03:18 am
Hi, welcome.

Please try the firmware attached with your CC3D.

You should use rescue for flash:
- disconnect board
- hit rescue button
- connect board
- Open button and browse where you saved the file attached
- flash

Anyway, register and create a Jira ticket here: https://librepilot.atlassian.net/projects/LP/issues

Title: Re: PPM not recognized, frame to short
Post by: sz on May 30, 2016, 06:30:37 pm
thank you for your quick replay!

I installed your firmware, but it also can't read the PPM.

I assuming the PPM input on PIN 8.

See also the attached screenshots.


Sebastian

Title: Re: PPM not recognized, frame to short
Post by: f5soh on May 30, 2016, 06:37:26 pm
The firmware i posted should allow 2.7ms pulses.
Try with another "normal" PPM receiver if works ?

Please check the ReceiverActivity, no need to populate the RCinput.

Go to UAVOBrowser > Data > ReceiverActivity

Title: Re: PPM not recognized, frame to short
Post by: sz on May 30, 2016, 06:58:03 pm
Quote
The firmware i posted should allow 2.7ms pulses.
Try with another "normal" PPM receiver if works ?
This is my only PPM setup. I have to downgrade my TX/RX. Will try it later.
The Ardupilot on APM can read the PPM. Right now I have both (CC3D and APM) connected parallel.

Quote
Please check the ReceiverActivity, no need to populate the RCinput.

Go to UAVOBrowser > Data > ReceiverActivity
please see screenhot. It doesn't look well.
Title: Re: PPM not recognized, frame to short
Post by: f5soh on May 30, 2016, 07:04:16 pm
Is a CC3D or a CC3D Atom ?
Title: Re: PPM not recognized, frame to short
Post by: sz on May 30, 2016, 07:15:15 pm
CC3D
Title: Re: PPM not recognized, frame to short
Post by: f5soh on May 30, 2016, 07:18:33 pm
Maybe you can try to setup the PPM input into the FlexiPort, just to be sure that not a Pin8/hardware issue.

Please create a JIRA ticket.
Title: Re: PPM not recognized, frame to short
Post by: f5soh on May 30, 2016, 07:26:18 pm
How many channels do you send from Tx side ?
Title: Re: PPM not recognized, frame to short
Post by: sz on May 30, 2016, 08:00:04 pm
The old ULRS firmware works.
16 chanels.
I will try the flexyport as input
Title: Re: PPM not recognized, frame to short
Post by: f5soh on May 30, 2016, 08:05:12 pm
Should be 12 channels max

old ULRS firmware support less channels ?

Try reducing the number of channels in your Tx
Title: Re: PPM not recognized, frame to short
Post by: f5soh on May 30, 2016, 08:33:12 pm
Just wanted to test the ULRS beta because i have a Txmodule 100mW but don't work.
No window after COM selection.
Beta software is a 60 days trial version ?  :-[

Scary...
Title: Re: PPM not recognized, frame to short
Post by: sz on May 30, 2016, 08:44:41 pm
Quote
Just wanted to test the ULRS beta because i have a Txmodule 100mW but don't work.
No window after COM selection.
I have to start the Software on one PC few times. There will be a new window at some time.

Quote
Beta software is a 60 days trial version ?
He says that he want to avoid a buggy version of his software. I assume there will be a stable version without limited time.

Quote
old ULRS firmware support less channels ?
yes, just 8.

Quote
Try reducing the number of channels in your Tx
I just configured 5 channels on openTX

Quote
Please create a JIRA ticket.
I will create a feature request for 16 channels. Like cleanflight (https://github.com/cleanflight/cleanflight/issues/343).
Title: Re: PPM not recognized, frame to short
Post by: f5soh on May 30, 2016, 09:43:28 pm
We can do like others, but i wonder why 16 channels are needed ?

Try firmware attached.
Title: Re: PPM not recognized, frame to short
Post by: sz on May 30, 2016, 10:11:08 pm
It works!
Thank you for your fast help and precise instructions!

Quote
We can do like others, but i wonder why 16 channels are needed ?
For me 8 channels are enough, but the ULRS developer seems to think 16 channels fix are better... I will ask him to optional choose between 12 and 16 channels.

I will still open a feature request via JIRA OK?


Thanks again a lot!
Title: Re: PPM not recognized, frame to short
Post by: f5soh on May 30, 2016, 10:13:41 pm
yes, Jira.
16 channels are really not needed for a LRS link, this should add some latency.

Title: Re: PPM not recognized, frame to short
Post by: sz on May 31, 2016, 07:28:49 am
I created an improvement ticked (https://librepilot.atlassian.net/browse/LP-326) in JIRA.