FrSky SPort Telemetry and Cube orange issues

I can’t get passthrough telemetry running with a cube orange…
FW 4.0.7
SERIAL2_OPTIONS: 7 (also tried 0, 3, 4, 8)

At the Taranis no new sensor is detected :confused:

All the H7s I’ve handled (Orange Cube, Holybro Durandal, Cuav Nora) can’t do the duplexing part.
They cand do the inversion, so you won’t need a MAX3232 anymore like in the Black Cube, original Pixhawk and all F4 FCs out there.

So, on H7, go for Invert_TX and Invert_RX in SERIALx_OPTIONS, and use a diode between the RX and TX wires to do the half-duplex part. Anode on TX, Cathode on both RX and wire to SPort. A simple 1N4001 or equivalent.

Thanks, I’ll try that.

I’m wondering a bit about the wiki:

F7/H7 based autopilots can directly connect to the TX pin of any UART and use this configuration:


SERIALx_OPTIONS = 7 (invert TX/RX,Half Duplex)

On the F7 it works. I have a single straight wire from the Holybro Pixhawk4 to the R-XSR.

On the H7 it doesn’t. I’ve tried every pull-up/pull-down combination when they came up, on a Durandal, to no avail. Back before them, with the Orange Cube, at first I gave up entierly and mounted a MAX, then started futzing around with hardware and settings and ended up with the diode.

FWIW there was an H7 specific problem with bi-dir dshot (a half-duplex protocol) that turned out to be caused by the GPIO speed (too fast therefore more noise). Its extremely unlikely this is the issue but might be worth a shot - mark the pin with SPEED_LOW in hwdef.dat

@andyp1per Do I understand correct that

will help for FrSky Telemetry and bi-dir dshot as well?

For bi-dir dshot this is already set programmatically - so no need for it in hwdef. For FrSky, no idea - just a guess worth trying - probably won’t work but if someone says it makes a difference then we can see whether there is a better way.

Thanks, so I got 2 possibilities to check at the weekend

I’ve compiled the sources already some time ago., but I didn’t have a look at hwdef so far. Any hint what GPIO speed needs to be set to low? :pleading_face:

Whatever pins are attached to your RX - if you tell me the board and the serial port you are using I can probably tell you.

Cube orange
Telem2 for FrSky Telemetry

For the ESC Telemetry I’m using the extra wire communication on GPS2 which is working fine for RPM, temp, current and volts for 6 motors. Would this be a future option also for bi-dshot?

Telem2 is USART 3 so you would do something like:


Bi-directional dshot does not need a telemetry wire or UART but you do have to have the motors connected to FMU outputs - i.e. AUX on CubeOrange

I gave it a try but no success :slightly_frowning_face:

so then there is the hardware option…

for prop testing I go with the extra wire ESC telemetry, this gives me more information on RPM and amps

but no extra wire for that would be heaven :wink: