Servers by jDrones

Some soldering required

Thanks for your help, your LUA scripts and comments. Now to get the PHL to fly similar to Betaflight, BF has much quicker response and close to zero prop wash compared to my current ac v3.6.4 settings.

Thanks to all in this forum! I just built a cable and it seems to work.
Only one issue encountered so far: I re-soldered three times and double-checked the wiring before I realized that the MAX boards must have one serial channel on each side- so make sure to solder all serial connections to the same side of the board!

3 posts were merged into an existing topic: An Open Source Frsky Telemetry Script for the Horus X10,X12 and Taranis X9D,X9E and QX7 radios

Hi, I built this telemetry cable found on the web, but from the previous schemes I saw that you don’t use the + that goes to the X8R, what is the correct solution?


You only need 1 (one) power supply to the board. It is a very bad idea to also put voltage on the Sport plug

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Thanks @LuisVale, I cutted the red in the servo plug and all work fine, the max3232 connetted for 20’ don’t became warm.
Thanks to Alex @yaapu for the wonderful work!

Можно не использовать черный провод на Sport приемника X8R, достаточно только жёлтый, так как - и + и так используются для подключения в канале управления.


English please!!!

You can not use the black wire on the Sport receiver X8R, only yellow, as - and + and so used to connect to the control channel.

Having a Ground Reference (black) is always a good practice, that is why it is used

  • and + in the Sport connector are needed to power external sensors. In the wiring diagram of the above, there is no need for such a connection. For example, it works without problems through one wire (yellow).

if you need FrSky sensors in line with this inverter then remove the power line coming from the PixHawk serial connection, and have everything powered from the X8R receiver, both the inverter and the FrSky sensors.

Again, one single power line to the inverter

Hi. Very helpful notes thanks. Can you confirm the wiring plan from the TTL side of the converter to the DF13 plug. Your photo shows two black wires. Which ones goes where ?.

This image clarifies the connections on the DF13 side RX/TX/5V/GND - Connect to the appropriate pins on the PixHawk, ie RX to TX, TX to RX, 5V to 5V and GND to GND

The “normal” plug will look like

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I’m using a NAVIO2 with copter 3.6.8 and a taranis QX7. Since I’m using the NAVIO2’s UART for something else, I’d like to get this setup working through the USB connection, and I think I’m mostly there. I used a 3.3V FTDI cable to do this. Since the signals need to be inverted, I used FTDI’s FT_PROG to invert the logic on RX and TX. The TX signal passes through a diode before the two signals are connected into one wire and sent into the X8R receiver (as described in the first post of this thread).

On the taranis, it seems like the yaapu telemetry is working, but not completely:

  • Artificial horizon is working (although very laggy)
  • Mavlink messages come through, although delayed
  • Always reads “No GPS” even if there is a GPS fix
  • Always reads “disarmed” even if the copter is armed
  • A few other items not working (heading, battery voltage)

I suspect the problem is that I’m using a 3.3V FTDI cable, so when the data passes through the diode it’s probably closer to 2.3 volts. Maybe this voltage level is too low for the X8R and that’s why I’m getting mixed results?

I am ordering a 5V ftdi cable, and will update with my results, but just wanted to post this in the meantime in case I’m missing something. Thanks.

hi, I’m afraid the NAVIO is suffering timing issues and cannot cope with the frsky telemetry protocol polling.
I would switch to a teensy with this firmware and feed mavlink to it.It’d work also with a one way TX only mavlink stream as long as you set the SRn_RATES parameters

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Thanks for the quick reply, Alex!
Ah, that’s too bad about the NAVIO timing issues… did not know that. I’ll order a teensy then, instead of the 5V cable.

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to use on the F405-STD and the same connection system as px4 2.8?


for stable ardupilot versions you use the same cable as px4 2.8 but latest dev master has additional serial options check here for up to date info

then and just put the diode between tx and rx plus the wire that goes pro s.port and rx?

I’ll take the test here.
I made the connections but I still had no telemetry signal

the lipo sensor signal is passing through the radio plus the ardupilot’s telimetry does not

Servers by jDrones