Can't get FrSky Passthrough working (4.0.5)

Hamstersocke · November 23, 2020, 7:23am

Thank you very much, SERIALx_OPTIONS set to 0 did it

Never tried without 4 (half-Duplex) because it sounded logical and in https://ardupilot.org/copter/docs/common-frsky-telemetry.html#common-frsky-telemetry
It says:
" In general, F4 based autopilots using an external bi-directional inverter can use any UART with the following configuration:

SERIALx_PROTOCOL =10
SERIALx_OPTIONS =160 (enable pull-up/pull-downs on TX and RX pins for those external inverter circuits that may require it)
"

hosein_gh · November 23, 2020, 8:03am

It good to hear that you got it working

Yes a little bit confusing but its for other flight controllers like omnibus f4 not pixhawk

Hamstersocke · November 23, 2020, 8:40pm

Your right, I think that came from me trying it first with a Mamba F405 and then moving on to the Pixhawk. If I’ve finished the second inverter I try it on the F405 again.

Alberto_Ds · November 24, 2020, 12:56pm

Hi, I also have a similar configuration and the same problem, even putting 0 on serial option unfortunately I have not solved. Omnibus nano F4 v6.0 and radiomaster
Here are the tests I did, can I try anything else? Thanks

ThePara · November 24, 2020, 1:16pm

The MAX323 boards have two circuits, one on each side of the board. Make sure all your wires are using the same side.

hosein_gh · November 24, 2020, 5:31pm

did you tried this ?

Alberto_Ds · November 24, 2020, 5:42pm

Not yet. This is my inverter:

Alberto_Ds · November 25, 2020, 7:46am

Why 2 diode 1n4007? Thanks.

hosein_gh · November 25, 2020, 7:58am

Some rs232 converters are not working with 5.2v
2 1n4007 will drop voltage to 3.2 to 4 volt and its will work

Alberto_Ds · November 25, 2020, 8:02am

Hi, thanks but if i have a 3.3V pad on FC (omnibus nano), can i try with this? Without diodes? My quad is micro only 3"

hosein_gh · November 25, 2020, 8:08am

If you have 3.3v ignore this step

Alberto_Ds · November 25, 2020, 8:15am

Now my inverter it’s connect to 5Vcc on FC pad. Can i try to connect to 3.3 pad?

hosein_gh · November 25, 2020, 9:05am

Yes try it
It might work

Alberto_Ds · November 25, 2020, 10:35am

Hi, don’t worked at 3.3V. I tryed protocol 4,10,23. Serial option 0,160. Baud rate 115,57. No new sensors on radiomaster.

hosein_gh · November 25, 2020, 11:06am

i dint used radiomaster, is it OpenTx ?

Alberto_Ds · November 25, 2020, 11:14am

Yes, open TX.

I connect only pad TX1 on TX pad inverter, could that be a problem?

ThePara · November 26, 2020, 10:27am

If your FC is based on a F4, you need both TX and RX connected.
Also, you need a diode between the inverted Tx-out and RX-out, where your S-Port wire goes to the receiver.

flyespen · November 26, 2020, 5:17pm

Have a look here, maybe it help you.

Hamstersocke · November 27, 2020, 4:41pm

After it worked on my initial setup I moved on to the next copter, it uses a R9M Mini OTA receiver.

I connected the inverter and enabled Frsky Passthrough, I get one new sensor, GPS. Has anyone an idea why only this one?
Maybe update the receiver?

Alberto_Ds · November 30, 2020, 8:15am

Thanks a lot!!! Work with TX an Rx connect! Baud rate 57 protocol 10 serial options 0.
Yappu work fine but radiomaster discovered only GPS coordinates. I don’t know how, but yappu works well.