LibrePilot Forum

General Category => General Discussion => Topic started by: Klingan on February 19, 2016, 10:22:04 am

Title: L9R rssi to revo over PPM
Post by: Klingan on February 19, 2016, 10:22:04 am

Hi

I'm setting up my twinstar II for longer range fpv and have added a revo, gps, minimosd, current sensor etc.

My current problem is that I don't know how to get the rssi from l9r rssi port to the revo and then to the minimosd.

I have the rssi and the rest of the pwm channels hooked up to a ppm converter and then connected to the receiver port on the revo.
I can't find anywhere in the wiki that explains how I tell librepilot what ppm channel the rssi is coming from.
Is this even possible since frsky rssi is analog?
I would like to avoid running more cables from the receiver on the wing to the fc and minimosd.

I have the osd flashed with the op specific version from the wiki but I don't think I have flashed any other "option" on top of that. I read somewhere about some hex files "all from revo", rssi_analog" etcetc.


Appreciate help : )

Title: Re: L9R rssi to revo over PPM
Post by: f5soh on February 19, 2016, 10:57:47 am

Hi,

Rssi from receiver can be connected directly to Osd but need a special firmware to support Revo features + Analog Rssi.

Do you know witch pin is used for Rssi analog input on Osd ?
MicroOSD or normal size ?

Laurent

Title: Re: L9R rssi to revo over PPM
Post by: Klingan on February 19, 2016, 12:20:50 pm

No I don't. It's the normal size minimosd.
So it's not possible to have the revo receive the rssi signal and then forward it to the osd?

Do you have a link to the firmware?

Thanks.

Title: Re: L9R rssi to revo over PPM
Post by: f5soh on February 19, 2016, 12:43:20 pm

Revo do not support Rssi input.

Added another firmware version fro Revo + Analog RSSI input
Current sensor still connected to Revo.
https://librepilot.atlassian.net/wiki/display/LPDOC/MinOPOSD+setup

Tell me if works, there is two versions. One with pin1 and another with pin3 (MicroOSD Kvteam)

Title: Re: L9R rssi to revo over PPM
Post by: Klingan on February 19, 2016, 12:50:11 pm

Thanks a lot! Will try it out this weekend.
Just have to run a new wire along the wing to the osd :)

Title: Re: L9R rssi to revo over PPM
Post by: f5soh on February 19, 2016, 12:59:34 pm

See https://code.google.com/archive/p/minoposd/wikis/AnalogRSSI.wiki for RSSI, need a RC filter.

Title: Re: L9R rssi to revo over PPM
Post by: Klingan on February 19, 2016, 03:49:44 pm

I can't find anywhere they sell rc filters but I guess making one from a 10k resistor and a 10uf capacitor would work, saw tutorial on YouTube.

Would this components work?
http://banggood.com/200Pcs-10-Value-5_1ohm10k-12W0_5Watt-Carbon-Film-Resistor-Assortment-Kit-p-1031851.html

And

http://banggood.com/1PC-50V-10UF-5x11mm-Electrolytic-Capacitor-p-984870.html

Title: Re: L9R rssi to revo over PPM
Post by: f5soh on February 19, 2016, 04:01:46 pm

When i say RC its just a R (resistor) and C (capacitor) filter.

You can make this from old components found on a old PCB, or visit your local shop...

Just a voltage divider that divide per (110 + 47) / 47 = 3.34 to avoid over voltage into OSD input
Capacitor smooth the voltage: 0.1µF or 100nF, usually a plastic capacitor, not electrolytic.
(https://forum.librepilot.org/index.php?action=dlattach;topic=886.0;attach=1644)

Title: Re: L9R rssi to revo over PPM
Post by: Klingan on February 21, 2016, 10:06:26 pm

I have tried to download and flash the board with the new hexfile but I get the error "The hex file did not contain an end flag. aborting" and then "bad hex".
Any idea why that happends?

Title: Re: L9R rssi to revo over PPM
Post by: f5soh on February 21, 2016, 10:17:16 pm

Opps sorry.  :-X

Wrong file. Try again download, tell me if ok now

Title: Re: L9R rssi to revo over PPM
Post by: Klingan on February 21, 2016, 11:08:37 pm

Will try tomorrow again.

And I think I have the kv mod with more pins, hard to know from googling.

And ain't does parts I linked right? A resistor and 10uf capacitor?

Thanks for all the help!

Title: Re: L9R rssi to revo over PPM
Post by: Klingan on February 24, 2016, 06:28:33 pm

Hex file flashed just fine. Now I just need components to try the rssi value.
Thanks

Title: Re: L9R rssi to revo over PPM
Post by: f5soh on February 24, 2016, 06:48:52 pm

Just follow schematic above.

the V1 source refers to your receiver RSSI pwm output, R8/C4 to ground and connect the osd Rssi input between Gnd and Red dot.

Capacitor is 100nF, like that :
(http://p.globalsources.com/IMAGES/PDT/B8817268090/Plastic-Encased-Film-Capacitor.jpg)