CRSF input for Trainer mode #1607

sk8board · 2022-02-19T16:41:24Z

Currently, Trainer mode only allows PPM or SBUS input. I am requesting CRSF input for Trainer mode.

Here is why.

I place a receiver in the JR module bay and connect the receiver to the Batt, Ground, and HeartBeat terminals. I then bind the receiver to the student transmitter. If the receiver will output PPM or SBUS, then this allows wireless trainer mode.

The problem is ELRS receivers do not output PPM or SBUS. Therefore, to use student transmitters with internal ELRS, there is a need for trainer mode to support CRSF protocol.

raphaelcoeffic · 2022-03-23T14:06:36Z

@wimalopaan would you be interested in adding this to your trainer protos?

rotorman · 2022-03-23T14:18:06Z

Luckily the channel data in CRSF is encoded 1-to-1 as with S.BUS. Here as a helper, a short CRSF parsing code by kobata, where he connected a HappyModel EP2 receiver via MCU to USB to act as a joystick: https://qiita.com/kobatan/items/40728fbb625057d9f42b

wimalopaan · 2022-03-23T15:05:14Z

@wimalopaan would you be interested in adding this to your trainer protos?

Yes, I'll have look at it

wimalopaan · 2022-03-23T15:22:22Z

Does anyone have a full protocol spec at hand? For this the control-part (no sensor reply) would be sufficient.

What would be the best test-setup for someone not owning CRSF hardware? Are the PC-based generators e.g. to use with some USB/serial converter?

wimalopaan · 2022-03-23T15:35:43Z

Luckily the channel data in CRSF is encoded 1-to-1 as with S.BUS. Here as a helper, a short CRSF parsing code by kobata, where he connected a HappyModel EP2 receiver via MCU to USB to act as a joystick: https://qiita.com/kobatan/items/40728fbb625057d9f42b

Crossfire is a bidi protocol as oppsed to SBUS oder IBUS-Controlpart.

At a first glance it looks like the Crossfire-RX does not expect anything from the FC (the radio in this case) to be returned for packets of type CRSF_ADDRESS_FLIGHT_CONTROLLER and CRSF_FRAMETYPE_RC_CHANNELS_PACKED. Is this assumption correct?

rotorman · 2022-03-23T15:44:37Z

Correct, you could just wire up the EP2 (CRSF) receiver TX line and leave the RX unconnected. Here a capture from the EP2 TX line (snippet):

C8 18 16 EC 03 9F 49 99 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 21 
C8 18 16 EC 03 9F 49 99 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 21
C8 18 16 EC 03 9F 49 99 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 21
C8 0C 14 35 00 64 0C 00 07 00 00 00 00 2E
C8 18 16 EC 03 9F 49 99 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 21 
C8 18 16 EC 03 9F 49 99 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 21
C8 18 16 EC 03 9F 49 99 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 21

What you get are CRSF_FRAMETYPE_RC_CHANNELS_PACKED (third byte 0x16) and CRSF_FRAMETYPE_LINK_STATISTICS (third byte 0x14) packets.

wimalopaan · 2022-03-23T15:46:18Z

Correct, you could just wire up the EP2 (CRSF) receiver TX line and leave the RX unconnected. Here a capture from the EP2 TX line (snippet):

C8 18 16 EC 03 9F 49 99 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 21 
C8 18 16 EC 03 9F 49 99 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 21
C8 18 16 EC 03 9F 49 99 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 21
C8 0C 14 35 00 64 0C 00 07 00 00 00 00 2E
C8 18 16 EC 03 9F 49 99 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 21 
C8 18 16 EC 03 9F 49 99 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 21
C8 18 16 EC 03 9F 49 99 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 21

Cool, thanks for the data: will use that as replay ...

wimalopaan · 2022-03-23T15:47:30Z

If I would like to get real HW, what would you suggest as RF-Module and RX? Available, simple and cheap...

rotorman · 2022-03-23T15:52:02Z

Here some more change in data for your experiments:

C8 18 16 EC 03 9F 49 99 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 21
C8 0C 14 35 00 64 0C 00 07 00 00 00 00 2E
C8 18 16 EA 03 9F 49 99 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 BB 
C8 18 16 EC 03 9F 4B 99 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 9D 
C8 18 16 EA 03 9F 4B 99 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 07 
C8 18 16 EC 03 9F 49 99 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 21 
C8 18 16 EC 03 9F 49 99 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 DC DA 37 
C8 18 16 EA 03 9F 4B 99 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 DC DA 11
C8 18 16 EC 03 9F 49 A9 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 FF 
C8 18 16 EC 03 9F 49 A9 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 7C D3 0B 
C8 18 16 EA 03 9F 4B A9 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 7C D3 2D 
C8 18 16 EA 03 9F 4B A9 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 D9 
C8 18 16 EC 03 9F 47 A9 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 61 
C8 18 16 EC 03 9F 47 B9 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 7C D3 DF 
C8 18 16 EC 03 9F 47 B9 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 2B 
C8 0C 14 35 00 64 0A 00 07 00 00 00 00 FC 
C8 18 16 EC 03 9F 45 B9 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 97 
C8 18 16 EC 03 9F 45 A9 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 DD 
C8 18 16 EC 03 9F 45 A9 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 7C D3 29 
C8 18 16 EC 03 9F 45 A9 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 DD
C8 0C 14 35 00 64 0B 00 07 00 00 00 00 68 
C8 18 16 EC 03 9F 45 B9 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 97 
C8 18 16 EC 03 9F 47 A9 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 7C D3 95 
C8 18 16 EA 03 9F 47 B9 F3 0B F0 81 0F 7C E0 03 1F F8 28 08 00 00 44 1C D7 B1
C8 0C 14 35 00 64 0A 00 07 00 00 00 00 FC

Have a look at HappyModel ES24TX and EP1 or EP2
Alternatively ES900TX and ES900RX if you want 868 MHz instead (868 MHz units cannot do 500 Hz ELRS, but they have longer range): http://www.happymodel.cn/index.php/2021/02/19/expresslrs-module-es915tx-long-range-915mhz-transmitter-and-es915rx-receiver/

wimalopaan · 2022-03-23T16:42:12Z

The other protocols like SBUS, IBUS oder SumD/V3 use a fixed known baudrate. As I read CRSF can use different baudrates. But in the hardware-tab there is no more a baudrate selector.

What would be your suggestion how to implement that (at first):

use a fixed baudrate (e.g. 400KBaud (or 420KBaud?))
use a user selectable baudrate (we need again a baudrate chooser)
autobaud (this may be only a try-n-error strategy by simple trying some well known baudrates).

raphaelcoeffic · 2022-03-23T16:49:02Z

400k is ok for a start, I think. Autobaud might be doable but it normally requires some bit patterns to be efficient and precise.

raphaelcoeffic · 2022-03-23T16:51:09Z

There is also the “brute force method” that just switches between known baud rates and tries to decode some traffic.

wimalopaan · 2022-03-23T16:52:10Z

There is also the “brute force method” that just switches between known baud rates and tries to decode some traffic.

... that's what I meant above under 3)

rotorman · 2022-03-23T17:40:37Z

Isn't the receiver side always 420k 8N1 irrespective of the update rate?
https://github.com/ExpressLRS/ExpressLRS/blob/2f78e06889f75996a7e7aaa6e63e5bd0f9ffd64d/src/lib/CrsfProtocol/crsf_protocol.h#L30

wimalopaan · 2022-03-25T15:13:54Z

In #1462 now we have

sbus (tested)
ibus (tested)
crsf (not tested)
sumd (not implemented)

This is available on AUX serial ports (AUX1 or AUX2).

wimalopaan · 2022-03-25T15:20:11Z

For SUMDV3 I intend to do the following:

first 16 channels are available as trainer input
the binary switches 1-64 are mapped onto a LS iff the LS is of sticky type with no(!) set or reset condition.

So, if one wants to use the binary switches that come in via SUMDV3 trainer, she has to setup the wanted LS as above before.

pfeerick · 2022-03-26T02:37:29Z

I'll grab another ELRS RX out later to try the CRSF support...

wimalopaan · 2022-03-26T06:02:08Z

I'll grab another ELRS RX out later to try the CRSF support...

I do not guarantee for anything ;-)

pfeerick · 2022-03-28T01:10:34Z

It seems to be working fine... only checked with the first four channels so far though :)

wimalopaan · 2022-03-28T05:00:14Z

It seems to be working fine... only checked with the first four channels so far though :)

Sounds good, thanks for testing.

sk8board · 2022-04-17T00:09:29Z

Thank you for working on this. Do you know if this enhancement is targeted for a release?

pfeerick · 2022-04-17T04:16:55Z

Should be in 2.8.

sk8board · 2022-10-12T15:11:44Z

@pfeerick @raphaelcoeffic

Should be in 2.8.

Is CRSF input for Trainer mode still planned for 2.8? If so, can I test this with 2.8.0-rc3?

gagarinlg · 2022-10-12T15:18:57Z

It is not going to be in 2.8.when you check PR #1462, you will see, that it needs to be rebased I clouding a bunch of manual work for translations.

wimalopaan · 2022-10-12T15:41:44Z

Maybe you want to checkout my
https://github.com/wimalopaan/edgetx/tree/wmibus_telem
branch for this. This is more uptodate.

pfeerick · 2022-10-12T22:06:32Z

So #1861 supercedes and includes #1462?

wimalopaan · 2022-10-13T06:59:14Z

Yes, it does.
It includes SBus/IBus/SumDV1-3 trainer input (up to 32 channels if EXTENDED_TRAINER is set) and FrSky-Telemetry-Input.

raphaelcoeffic · 2022-10-13T07:09:17Z

It includes SBus/IBus/SumDV1-3 trainer input (up to 32 channels if EXTENDED_TRAINER is set) and FrSky-Telemetry-Input.

Kind of a "pot pourri", we'll need to sort that out and extract features one by one.

wimalopaan · 2022-10-13T07:18:24Z

Yes, it is. Actually I don't have time to sort that out by myself ... sorry.
But please don't hesitate to cherry pick the parts.

pfeerick · 2022-10-13T07:32:31Z

Lol... have no fear, the skeleton will be picked clean, and credit given where credit is due ;)

sk8board added the enhancement ✨ New feature or request label Feb 19, 2022

pfeerick self-assigned this Mar 26, 2022

pfeerick linked a pull request Mar 26, 2022 that will close this issue

Enable serial trainer for foreign protocols (Ibus/SumD) #1462

Closed

sk8board mentioned this issue Sep 27, 2022

Cannot change to a different model 2.7.0 T-Pro ELRS #1898

Closed

1 task

pfeerick linked a pull request Dec 23, 2023 that will close this issue

Enable serial trainer for foreign protocols (SBUS improvements / CRSF / Ibus / SumD) #4102

Draft

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

CRSF input for Trainer mode #1607

CRSF input for Trainer mode #1607

sk8board commented Feb 19, 2022 •

edited

Loading

raphaelcoeffic commented Mar 23, 2022

rotorman commented Mar 23, 2022 •

edited

Loading

wimalopaan commented Mar 23, 2022

wimalopaan commented Mar 23, 2022

wimalopaan commented Mar 23, 2022 •

edited

Loading

rotorman commented Mar 23, 2022 •

edited

Loading

wimalopaan commented Mar 23, 2022

wimalopaan commented Mar 23, 2022

rotorman commented Mar 23, 2022 •

edited

Loading

wimalopaan commented Mar 23, 2022 •

edited

Loading

raphaelcoeffic commented Mar 23, 2022 •

edited

Loading

raphaelcoeffic commented Mar 23, 2022

wimalopaan commented Mar 23, 2022

rotorman commented Mar 23, 2022 •

edited

Loading

wimalopaan commented Mar 25, 2022 •

edited

Loading

wimalopaan commented Mar 25, 2022 •

edited

Loading

pfeerick commented Mar 26, 2022

wimalopaan commented Mar 26, 2022

pfeerick commented Mar 28, 2022

wimalopaan commented Mar 28, 2022

sk8board commented Apr 17, 2022

pfeerick commented Apr 17, 2022

sk8board commented Oct 12, 2022

gagarinlg commented Oct 12, 2022

wimalopaan commented Oct 12, 2022

pfeerick commented Oct 12, 2022

wimalopaan commented Oct 13, 2022

raphaelcoeffic commented Oct 13, 2022

wimalopaan commented Oct 13, 2022

pfeerick commented Oct 13, 2022

CRSF input for Trainer mode #1607

CRSF input for Trainer mode #1607

Comments

sk8board commented Feb 19, 2022 • edited Loading

raphaelcoeffic commented Mar 23, 2022

rotorman commented Mar 23, 2022 • edited Loading

wimalopaan commented Mar 23, 2022

wimalopaan commented Mar 23, 2022

wimalopaan commented Mar 23, 2022 • edited Loading

rotorman commented Mar 23, 2022 • edited Loading

wimalopaan commented Mar 23, 2022

wimalopaan commented Mar 23, 2022

rotorman commented Mar 23, 2022 • edited Loading

wimalopaan commented Mar 23, 2022 • edited Loading

raphaelcoeffic commented Mar 23, 2022 • edited Loading

raphaelcoeffic commented Mar 23, 2022

wimalopaan commented Mar 23, 2022

rotorman commented Mar 23, 2022 • edited Loading

wimalopaan commented Mar 25, 2022 • edited Loading

wimalopaan commented Mar 25, 2022 • edited Loading

pfeerick commented Mar 26, 2022

wimalopaan commented Mar 26, 2022

pfeerick commented Mar 28, 2022

wimalopaan commented Mar 28, 2022

sk8board commented Apr 17, 2022

pfeerick commented Apr 17, 2022

sk8board commented Oct 12, 2022

gagarinlg commented Oct 12, 2022

wimalopaan commented Oct 12, 2022

pfeerick commented Oct 12, 2022

wimalopaan commented Oct 13, 2022

raphaelcoeffic commented Oct 13, 2022

wimalopaan commented Oct 13, 2022

pfeerick commented Oct 13, 2022

sk8board commented Feb 19, 2022 •

edited

Loading

rotorman commented Mar 23, 2022 •

edited

Loading

wimalopaan commented Mar 23, 2022 •

edited

Loading

rotorman commented Mar 23, 2022 •

edited

Loading

rotorman commented Mar 23, 2022 •

edited

Loading

wimalopaan commented Mar 23, 2022 •

edited

Loading

raphaelcoeffic commented Mar 23, 2022 •

edited

Loading

rotorman commented Mar 23, 2022 •

edited

Loading

wimalopaan commented Mar 25, 2022 •

edited

Loading

wimalopaan commented Mar 25, 2022 •

edited

Loading