Please have a look again.
I see. Well, I was sure it’s better to use some kind of CMOS IC:
no that just gets rid of the resistors required in a discrete bi-directional inverter…which works perfectly
like this https://quadmeup.com/smartport-inverter-for-f4-flight-controllers/
As I can see in the comments it exactly is not working perfectly and needs modification. ) Which is not the case with dedicated inverters.
But thanks anyway for the link.
I find the fact that Half-Duplex requires connecting to the TX signal soooo confusing. No telemetry I just connect to the RX pin, with telemetry I connect to the TX pin. Is this a hardware limitation?
It is the default for half-duplex for STM32, but you can set the SWAP option in SERIALn_OPTIONS to tell the uart to swap TX and RX.
That doesn’t work for me on a Pixhawk1 - is it an F7/H7 thing only?
it does work on F4, but for most receivers you need an external inverter
The receiver I am using is non-inverted?
I’ve got a few questions as I’m finally upgrading from my old Flysky FS-TH9X to a Radiomaster TX-16S (pre-order for May) and want telemetry etc.
I have a Matek F405-STD & Frsky R-XSR (but no TX yet so can’t test this), if I use the uninverted smartport (I believe fport uses the smartport output) out pad will that solve the inverting issue and work fine (if so will this also work with my pixhawks)?
If not, the F405 has a built in inverter for the sbus, is it possible to retask that to do the fport?
BRD_ALT_CONFIG=1
SERIAL5_PROTOCOL=23
SERIAL5_OPTIONS=160
RSSI_TYPE=3
where I put these parameters on the Mateksys F405-STD
not all options appear
you must be using the “latest” firmware, not a stable release
unless it has an FPort output specifically marked “inverted FPort” then the signal levels of a standard FPort signal is opposite that of a normal serial UART…hence the need for an external bi-directional inverter circuit on F4 based autpilots…F7/H7 have controllable inverters for the TX and RX inputs that F4 do not
I’m going to download the latest version to see if it appears since I can’t make the telemetry work on it even using an inverter
how do I enable it on Pixhawk 2.4?
since I can’t make it work on another card I would like to test this one to see if everything is right
Yeah understand, but I’m not using FPort 
so there is no support yet thanks for responding
Hello!
Just tryed FPort on omnibus f4 pro and r9mm
In working nice using inverted fport pin
Serial1 protocol = Rcin
Serial1 options = 4
Baud = 57
Using Tx pin on omnibus Serial1 port
FPort also works on mRo Control Zero with R-XSR including yaapu telemetry script.
R-XSR normal SPort <-> FrSky_OUT (FRONT PIN11)
SERIAL4_PROTOCOL = 23
SERIAL4_OPTIONS = 7
RSSI_TYPE = 3
R-XSR: RXSR_ACCST_2.1.0_Fport_LBT
mRo Control Zero: ArduPlane V4.1.0dev (04d760d5)
yaapu: 1.8.1