RadioMaster DBR4 Dual Band Xross Gemini ExpressLRS

[nmsantarelli]

Hello everyone on the forum,
I would like to know if anyone uses the DBR4 (xrossband) rx with the Spirit2 and if so how it should be connected.

In the examples I only see the RP3-H (crossfire).

Thanks in advance for an answer

[nmsantarelli]

Good morning everyone,
Last night I installed the NOMAD in the radio and successfully connected the receiver to the radio.

I started the Spirit2 with the USB cable to:
1) Update the firmware according to the manual. OK.
2) Select the CRSF/ELRS receiver protocol as per the manual. OK.
3) Swap the channels as indicated in the manual (throttle - elevator). OK

Result:
- The elevator/throttle controls didn't work
- The aileron/tail/pitch controls were fine, although the movement was jerky and non-linear.

I launched LUA TBS, which displayed:
- NOMAD
- SPIRIT
- DBR4

I launched "NOMAD" and after loading, the transmitter parameters were visible.
I launched "DBR4" and after loading, the transmitter parameters were visible.
I launched "Spirit FBL" and during loading (the parameters started to appear, but it stopped at a certain point, displaying an error).

Correction dated 12/07/25
WRONG: I noticed that in the DBR4 setup, the following protocols can be selected: CRSF, SBUS, PPM, PWM.
WRONG: Question: If I change the protocol from CRSF to SBUS, I imagine I'll then have to change the connection on the Spirit2 according to the Spirit2 manual, right?
The problem is during the loading of the FC variables which creates the error (see photo)

[nmsantarelli]

Good morning everyone,
Last night I installed the NOMAD in the radio and successfully connected the receiver to the radio.

I started the Spirit2 with the USB cable to:
1) Update the firmware according to the manual. OK.
2) Select the CRSF/ELRS receiver protocol as per the manual. OK.
3) Swap the channels as indicated in the manual (throttle - elevator). OK

Result:
- The elevator/throttle controls didn't work
- The aileron/tail/pitch controls were fine, although the movement was jerky and non-linear.

I launched LUA TBS, which displayed:
- NOMAD
- SPIRIT
- DBR4

I launched "NOMAD" and after loading, the transmitter parameters were visible.
I launched "DBR4" and after loading, the transmitter parameters were visible.
I launched "Spirit FBL" and during loading (the parameters started to appear, but it stopped at a certain point, displaying an error).

I noticed that in the DBR4 setup, the following protocols can be selected: CRSF, SBUS, PPM, PWM.

Question: If I change the protocol from CRSF to SBUS, I imagine I'll then have to change the connection on the Spirit2 according to the Spirit2 manual, right?

[nmsantarelli]

Can this error be resolved? If so, how?

Thanks

[nmsantarelli]

Hello everyone on the forum,
I just wanted to say that the above problem was caused by the elrsV3.lua script (which wasn't working). I solved it with the latest release found at "https://github.com/ExpressLRS/ExpressLRS/issues/1864" where I downloaded version 3.5.6 and everything works.

I only have one question regarding the Spirit2:
With standard receivers that connect to the Ale/Pitt/Rud ports, can I connect the USB cable to the sys port and use the Spirit Setting software to calibrate the sticks on the diagnostic page.

With ELRS, the receiver connection goes to the sys port, so I can't calibrate the sticks. How can I fix this?
I'm asking because I have the feeling that the stick travel has changed compared to when I had the previous SPM4651T receiver.

Thank you for reading, and even more so for your help.

Regards
nmsantarelli

[ZeXx86]

Hello,

you can still use SYS port but disconnecting receiver wires (and repower) is necessary.
With Spirit 2 you can still use original wiring with RUD/AIL ports for ELRS, but there telemetry might not work properly.