Passthrough telemetry over CRSF (crossfire)

yaapu · November 10, 2021, 2:12pm

Hi, you need to use the custom build server and manually enable CRSF and all other features that you need, note that the build can fail if you enable too much and exceed the KakuteF7 flash size

please note that the current version of the build server only supports building latest master

Benjamin_Gianneschi · November 10, 2021, 3:38pm

I am using the custom build with crsf, crsf text turned on.

Btw I also have msp osd turned on, which does work with my dji hd system. I also tried turning on as many sensors as I could. This is on a 5” quad. “Copter” build.

I did just rebuild the custom kakute F7 code maybe you could have a quick look at the log?

yaapu · November 10, 2021, 5:29pm

Does regular CRSF work? Are you able to discover standard CRSF sensors?

yaapu · November 10, 2021, 5:31pm

…and

did you enable passthrough on ArduPilot by setting RC_OPTIONS = current_value + 256
did you enable CRSF support in my script/widget?
are you using version 1.9.5 or 1.9.6 of my scripts/widgets?

Benjamin_Gianneschi · November 12, 2021, 4:25pm

Yes tried the latest script. Same problem with 1.9.3 1.9.4, 1.9.5 etc. I don’t think it’s the script, as I said all works on my other FC’s. Btw I did have a kakute F7 1.5 and a kakute F7 HD. They both have the same problems. I’m switching the kakute F7 hd to expresslrs this weekend.

I do get crsf Rx sensors but I only get 3 ardupilot sensors. And those sensors don’t update.

Rc_options = 288. Note in ardupilot 4.2 dev you get a menu when selecting this option. I just selected crsf passthrough.

The crsf does work with full control.

dkemxr · November 12, 2021, 4:36pm

That’s more a function of Mission Planner Beta. It’s available for current Stable V4.1.1 also.

Benjamin_Gianneschi · November 12, 2021, 4:38pm

Yes, but I wanted msp osd and the “normal” build doesn’t have that for the kakute f7.

Without msp osd and yappu not working I’d have no telemetry at all.

dkemxr · November 12, 2021, 4:46pm

I was just saying you don’t need 4.2 dev to get that menu option in Mission Planner.

Ojwhaaa_Ojwhaaa · November 14, 2021, 9:13pm

I think you have a very special Crossfire Micro Nano TX and RX because I can only get 50 till 100m with Mavlink telemetry on my GCS only, until the connection is broken again.
I’m not talking about the RC link that is working fine for a very long range but the MavLink telemetry is just crap and useless.
I would never buy a Crossfire system again!

CrashTestPilot · November 15, 2021, 3:58pm

RF mode is set from the transmitter LUA and is fixed. Here is the page on the relevant signal health indicators:

Joshk1 · November 21, 2021, 4:02am

Hi,

DMA enabled uart on Matek 743 slim? Maybe a very dumb question but… How do i know which one it is? Link below says UART6 NODMA. I know very stupid. But if I swap to another available UART I reduced the risk of dropped frames/failsafe?

github.com

ArduPilot/ardupilot/blob/master/libraries/AP_HAL_ChibiOS/hwdef/MatekH743/hwdef.dat#L102-L135

    
      
          # order of UARTs (and USB)
          SERIAL_ORDER OTG1 UART7 USART1 USART2 USART3 UART8 UART4 USART6 OTG2
          
          
# USART1 (telem2)
          PA10 USART1_RX USART1
          PA9  USART1_TX USART1
          
          
# USART2 (GPS1)
          PD5 USART2_TX USART2
          PD6 USART2_RX USART2
          
          
# USART3 (GPS2)
          PD9 USART3_RX USART3
          PD8 USART3_TX USART3
          
          
# UART4 (spare)
          PB9 UART4_TX UART4
          PB8 UART4_RX UART4
          
          
# USART6 (RC input), SERIAL7

This file has been truncated. show original

Andy P’s video has been a great help and the Yappu script is a nice addition. Just don’t like the errors popping up.

Regards,
JOSH

relaxibus · November 24, 2021, 8:42am

Hi! I made a industrial-grade RC with CRSF TX/RX link. As I’m able to decode the CRSF messages, I’m not able to decode the Passthrough messages as I have no idea of the protocol. Can you post a link or a Passthrough spec so I can add this in the RC? Here a screenshot of my telemetry screen. What I’m missing is Magnetic Heading, Relative Altitude, GPS Type.
Telemetry_Page1-VLOS_v5

andyp1per · November 24, 2021, 9:30am

The only spec is the code: ardupilot/AP_CRSF_Telem.cpp at master · ArduPilot/ardupilot · GitHub

relaxibus · November 24, 2021, 2:37pm

Hmmm… Why I don’t find any reference to the CRSF IDs 0x80, 0x7F, 0xF0, 0xF1 and 0xF2?
Ardupilot is sending out this frames, so there must be defined somewhere, not?

andyp1per · November 24, 2021, 2:41pm

github.com

ArduPilot/ardupilot/blob/36562ed30b3cd1022f1eb7bc6e26d264711f1f46/libraries/AP_RCProtocol/AP_RCProtocol_CRSF.h#L67

    
      
              CRSF_FRAMETYPE_FLIGHT_MODE = 0x21,
              // Extended Header Frames, range: 0x28 to 0x96
              CRSF_FRAMETYPE_PARAM_DEVICE_PING = 0x28,
              CRSF_FRAMETYPE_PARAM_DEVICE_INFO = 0x29,
              CRSF_FRAMETYPE_PARAMETER_SETTINGS_ENTRY = 0x2B,
              CRSF_FRAMETYPE_PARAMETER_READ = 0x2C,
              CRSF_FRAMETYPE_PARAMETER_WRITE = 0x2D,
              CRSF_FRAMETYPE_COMMAND = 0x32,
              // Custom Telemetry Frames 0x7F,0x80
              CRSF_FRAMETYPE_AP_CUSTOM_TELEM_LEGACY = 0x7F,   // as suggested by Remo Masina for fw < 4.06
              CRSF_FRAMETYPE_AP_CUSTOM_TELEM = 0x80,          // reserved for ArduPilot by TBS, requires fw >= 4.06
          };
          
          
// Command IDs for CRSF_FRAMETYPE_COMMAND
          enum CommandID {
              CRSF_COMMAND_FC = 0x01,
              CRSF_COMMAND_BLUETOOTH = 0x03,
              CRSF_COMMAND_OSD = 0x05,
              CRSF_COMMAND_VTX = 0x08,
              CRSF_COMMAND_LED = 0x09,
              CRSF_COMMAND_GENERAL = 0x0A,

yaapu · November 24, 2021, 2:48pm

Hi, Frame 0x80 is just a container for passthrough frsky frames,

there are 3 types of 0x80 frames identified by the first payload byte:

status text frames
single passthrough telemetry frame
multi passthrough telemetry frame

you can get an idea of the decoding algo by checking my widget lua code, here

each passthrough telemetry frame is then fed to the processTelemetry() function which does the passthrough decoding here

relaxibus · November 24, 2021, 3:49pm

Thanks to all! Will glide into it.
Just for clarity: How will Magnetic Heading, Relative Altitude and GPS Type be sent? There are no native CRSF messages, right?

yaapu · November 24, 2021, 5:42pm

yes, if you rather use native frames just check in the ardupilot library for the relevant calc_ functions

relaxibus · November 27, 2021, 12:13pm

Thanks Alex, very appreciated!

Moksh · December 3, 2021, 5:15am

Still i need this version , because my pixhawk 2mb flash doesn’t work with ELRS 1.1.2 at AP 4.1.1 stable i tried serial 4and5 but no luck

Maybe I assume rc stick doesn’t showing on rc sliders page ? @yaapu