Only GPS/RSSI/BtRx sensors found on my FrSky Rxsr/TaranisX9D telemetry feedback

Hi. I’m getting troubles setting up a decent telemetry feedback from my KakuteH7 AP, through an FrSky RXSR radio receiver connected (and firmware upgraded to F.Port protocol). Then only sensors detected by my TaranisX9D are GPS (actual & correct position), RSSI (90dB) and BtRx (4.81V). I cannot get access to the most valuable one : VFAS (for battery voltage) which is not detected at all.

My current settings are as follows:

> Physical : Autopilot Serial6 TX pin + GND + 5V connected (3 wires only for F.Port)

> Logical : as per Ardupilot recommendations for F.Port connection,
. BRD_ALT_CONFIG = 1
. SERIAL6_PROTOCOL = 23 (RCIN)
. SERIAL6_OPTIONS = 7

Any idea? Any suggestion? Thanks.

I have recently a similar configuration on a Kopis Cinewhoop 105mm with Kakute H7 mini nand, in which I have installed ArduCopter, and added camera at Vi+CAM, VTX at Vtx (with OSD info), optical flow+sonar Micoair MTF-01 at UART2, GPS+compass at UART3/I2C, wifi telemetry at UART4, I2C display, 32 WS2812 leds, using Radiomaster transmitter TX16S SE with EdgeTX and Yaapu script, and receiver FrSky R-XSR (telemetry: F.port to T6).
EK3 source (optical flow (indoors) or GPS (outdoors)) chosen with transmitter switch.

I see VFAS (indeed needed) on transmitter. My configuration is slightly different:

  • v4.5.7 with the annoying unknown message (44).
  • I don’t have BRD_ALT_CONFIG.

So far, I have only tested it indoors (GPS gets fix); it flies well and all seems to work. I miss indoors trajectory at .tlog from Optical Flow, although it seems a difficult task.

What is your version?

> EK3 source (optical flow (indoors) or GPS (outdoors)) chosen with transmitter switch.
> What is your version?

Hi Webillo. Thanks so much for bouncing on this thread.

We have more or less the same configuration; mine includes a uBlox M10Q GNSS, an RM3100 compass and a MicoAir MTF-01 RangeFinder/OpticalFlow combo. My machine swaps from GNSS to RangeFinder/OpticalFlow through an RC Switch selecting the EK3 source.

Concerning these 3 parameters : 

. SERIAL6_PROTOCOL = 23 (RCIN)
. SERIAL6_OPTIONS = 7 (invertTX + invertRX + HalfDuplex)
. BRD_ALT_CONFIG = 1 (alternate configuration)

I've tried nearly every single combination to get this damned VFAS to show, at no avail !


Receiver F.port goes to T6 (blue wire soldering), so hardware seems correct.

Check parameters for v4.5.7: BRD_ALT_CONFIG does not appear, as in my configuration. It may be doing strange things in yours. Install v4.5.7.

I made it the other way round… success !

  1. downloaded the following LUA script from here
  2. placed this file in a scripts folder located on the AP sdcard in the APM folder;
  3. enabled lua scripts on my Kakute through SCR_ENABLE = 1
  4. reboot

and then, only magic… VFAS and CURRENT now displayed in my TaranisX9D. Yesssss

Things should be simpler:


without doing anything at all.

Have you tried Delete all and then Discover new?