I had tried (and failed with) T20 → wireless → ELRS_Rx → wire → HM30
But if direct wiring between T20 and HM30 is possible, I would like to know HOW!!
That’s strange. If you still want to go this route, I’m happy to try to help. I’ve connected between an radio like the T20 and a SBUS ELRS RX many times - when you change the RX to output SBUS, it doesn’t change the communication protocol between the TX and RX, only what kind of signals come out of the RX wires, if that makes sense. So it shouldn’t have anything to do with you losing connection between the TX and RX.
Thank you both for the answers!
With the ELRS 3.3.2, now I had tried to set the ELRS RX to S.BUS output, its output to the HM30 RC input (pins 1,3,4), set the HM30 setting to the S.BUS;
the betaflight is set to the S.BUS respectively because output of the air unit is always S.BUS.
Now I can see AETR channels in the BETAFLIGHT! So T20 can be connected to the HM30 over SBUS.
The next problem what I got, unfortunately, is that only AETR are transmitted, all other AUX are out of scales. Something is going wrong, because even if the ELRS RX is set to CRSF and directly connected to the betaflight RC over T2 R2 over UART, only AETR are received 
I had set the channels on T20 for the switches as in https://youtu.be/Xv0FKQo35LA?feature=shared&t=274
Check first in your radio’s channel monitor that your radio outputs channels above 1 to 4 at all. And if not, read User Manual for Monochrome Screen Radios - EdgeTX User Manual
Also, as this has nothing to do with Siyi HM30 anymore → head over to EdgeTX or ExpressLRS Discord and get further help there. Also be sure to read carefully Switch Configs - ExpressLRS
Does it mean that you want to use HM30 as a system to transmit video stream in as high bitrate as possible in as long range as possible?
Thanks for your help.
It was a difficult supply chain situation during the epidemic that we had to use different MCU.
The latest lot of HM30 has been coming with GD for ground unit and N32 for air unit only for quite a while.
Hi
Do I need any special USB to Eth adapter to get the video?
I just ordered the cheapest one I found in an Internet Shop. It works. But disable the WiFi in your Phone.
Thanx everybody for the help!
I would like to confirm that I was able to get first 12 RC channels to work on HM30 (using ELTR, Rx → S.BUS)
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So back to firmware. Should we use Siyi assistant or web interface?
Thanks.
SIYI Assistant is for firmware update
@SIYI @Risto Hi. Recently bought HM30. Could you help me to connect it via RC input port to Jumper T-pro V2 ELRS (built-in) via its port for external module. There are 5 pins but I don’t know which to connect. Jumper support doesn’t respond yet.
As I could test these wires with my multimeter, black is ground, yellow is +7.4V)
Nevermind, it’s black and blue wires from my photo. It works now
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https://drive.google.com/file/d/11ST6743pOrU-lSYjtCDdHJaoXEHOK-fO/view?usp=sharing
Can I have the link again because i can’t get the configuration right.
I have a school project that i need to finish and give to the professor.
So if you please can help with that
Thank you
Rad Nik
Hi Risto,
I’m having a problem and I can’t fix it. The HM30 and the Air Unit are making a connection. The triple yellow light flashes on the HM30. When I examine the manual, I understand that this is a data overrun, but I could not find anything to solve the problem. I did a firmware update to both components but still the same. Also, the Air Unit resets itself after a while after installing the camera. I think it is due to the high data overrun. How can I solve it? You can see the firmware versions in the image below:
Your air unit FPV firmware is 6.2.2 which belongs to the dual edition, while the ground unit is 0.2.2 which is normal edition. They do not match perfectly.
Please try to use 0.X.X firmware with 0.X.X firmware and 6.X.X with 6.X.X.
Hi Frank,
I have Futaba 18SZ remote and its receiver for my plane. When I connect the receiver to the HM30, I get different rc values. When I examined, I have seen that the calibration is not perfect. I downloaded Siyi Assistant and here is the photo of my rc values. At the bottom, there is a calibrate button but i guess it doesn’t work. Is there a way to calibrate my RC over Siyi Assistant?
The calibration in SIYI Assistant only works for some old SIYI radio controllers, not compatible for third-party RC
