DSMR issues - Spektrum surface receiver SR6200A

[IdefixRC]

Hello there,

I came across an interesting issue with my MT12 and a Spektrum surface receiver (SR6200A).

I have 2x MT12 and 2x Arrma Vorteks Cars with SR6200A receivers.
One radio (EdgeTX v2.10.5 with MM v1.3.4.0) connected using the R1-F mode (DSM2SFC - 6 is missing from the FW build as listed here) after a few tries and works although Telemetry comes and goes all the time.

The 2nd MT12 (same SW version as the other) and Vorteks connect when binding. Telemetry comes up, drops and never comes back up again and when I cycle the power on the receiver, the receiver goes back into binding mode directly when powered back on.

In addition the issue that only receiver number [00] can be used remains also in 1.3.4.0 - see video of the issue from another user here: https://www.youtube.com/watch?v=KLTIEe_VTGY

Any help would be highly appreciated ! Thanks a lot

[IdefixRC]

Update to my earlier post: I tried different versions of the MM FW and got it to bind with version 1.3.3.14 of the Multi Module FW, higher versions all ad the same issue of connecting but not keeping the bind after a receiver power cycle.

It even works now if I select the [01] receiver number which with the other FW versions resulted in no connection at all.
Maybe this helps to troubleshoot.
Thanks

[pascallanger]

I don't have any DSMR receiver to test... Can you narrow down the exact version from which the issue started?
Like:

• Version x.x.x.x works
• Version x.x.x.x broken
  From there I might be able to find out what happened

[IdefixRC]

Hello Pascal,

Here is what I have tested so far:

• Version 1.3.3.14 works
• Version 1.3.3.20 broken

Hope this helps

[pascallanger]

Are you sure? There is not a single line changed in the DSM protocol between v1.3.3.14 and v1.3.3.20, nothing related to the CYRF and nothing related to the main loop.
The only thing that could have an impact is the board. @benlye do you have a way to do a build of v1.3.3.20 with the old board so that @IdefixRC can test to see if the issue is really with the board?

[pascallanger]

@benlye forget... I think I found the issue.
I'm pretty sure v1.3.3.20 works fine... It broke on v1.3.3.33 when DSM clone was introduced...
@IdefixRC Please try the test version v1.3.4.26 with your DSMR receiver including multiple receiver numbers.

[IdefixRC]

@pascallanger, thanks for the quick fix.
I have tested v1.3.4.26 with 2 different MT12 and 2 different Spektrum SR6200A receivers (one of the receivers previously only worked with v1.3.3.14 and would not retain the bind after power cycle with the other versions).
Both are working well. I tried multiple binds with model number 00, 01, 02, 03 and all 4 worked fine (connects and stays connected after power cycle).

Only telemetry is still patchy. I might be imagining things but when I bind with Model Number 00 or 01, telemetry drops out sporadically but is semi stable (stays on for 15-30 seconds before dropping). If I bind with number 02 or 03, telemetry comes and goes every few seconds. Not sure how I can help you troubleshoot the telemetry part of the connection.

Thanks !

[pascallanger]

That's surprising as I'm talking to someone else which has no telemetry drops on whatever model number. He has let his radio and car turned on for 30 minutes without a single telemetry lost message while walking around with the radio in his house to test at different distances.
He is using SR215 and SR315 in his tests, that's the only difference I can see. So the issue seems to be targeted to your RXs model...
Anyway, I've done a slight change. Can you try the latest test version 1.3.4.27?
If it doesn't work better, you'll need to send me on of these receivers or make a donation so I can purchase one.

[IdefixRC]

Thanks @pascallanger.

I have tested 1.3.4.27 and it has the same issue unfortunately. :-(
I have made a video showing the telemetry issue. You can check it here: https://youtube.com/shorts/rW6Nb3ZMbwI?feature=share

Does the other user use the Radiomaster MT12? Here is another report of a similar telemetry issue (Radiomaster MT12 and a Spektrum SR315 Receiver): #992
If he uses a different TX, maybe it is not the receiver but has something to do with the TX?

Another user in the link above states that it works better in low power mode vs normal mode. Here is another user (MT12 and SR6200A) with the same telemetry cut out issues: https://www.arrmaforum.com/threads/dx3s-avc-knob-and-replicating-advanced-avc-settings-with-the-radiomaster-mt12.73559/post-1190707

[pascallanger]

MT12 or any other radio doesn't change anything...
In the other report, it looks like the SR315 is connected to an ESC with telemetry. Is it your case too? If it is then can you try without connecting this ESC and power the RX with just an external battery. Looking at your video it looks like your telemetry is stable for 30 seconds then starts to drop and go, that might be the time the ESC takes to send back it's data...
The other user doesn't have an ESC with telemetry and its SR315 telemetry works fine.

[IdefixRC]

Hello @pascallanger,

thanks for the continued effort on this one.
Correct, the Receiver is connected to a Spektrum SMART ESC with telemetry from the ESC.
Note that the SSR6200A receiver is a AVC receiver with integrated Gyro and sends telemetry data on it's own as well.

I have done the following:

1. disconnected ESC
2. only left steering connected to the receiver
3. powered the receiver via an external receiver pack
4. rebind receiver with MT12 on 1.3.4.27 - model # 01
5. similar outcome as before with ESC connected

Please see the video here: https://youtube.com/shorts/kMxNn5pEVag

for the 2nd test I used the same setup as above but rebind the receiver on model # 02
Although I believe the telemetry lost/reconnect is way more frequent with this model number I wonder how model numbers can impact the telemetry function? Maybe this helps to narrow it down.

Please see the video here: https://youtube.com/shorts/yFRZZUtY7v8

[ken830]

1 tested both 1.3.4.26 and 1.3.4.28 on my RadioMaster RM 4-in-1 External Module connected to my MT12. This is connecting to an SR6200A. Still get telemetry cutting out. In the telemetry screen I can see the RSSI will drop from 90 to 0 instantly. With 1.3.4.26, I feel like it's stuck at 0 when it happens, but with 1.3.4.28, it comes back and holds it more steadily. If I'm in the next room, holding the radio in certain positions, I can get telemetry to stay connected for quite some time (~30s to 1m). Many times (but not always) I seem to be able to bring it back by just wrapping my hand around the external antenna. When telemetry comes back online, the RSSI jumps from a steady 0 to 90 or so...

[Dan0111]

Hi,

I have exactly the same problem. I can reproduce it with the Spektrum SR6200A and the SR6100AT. Both are telemetry receivers with integrated AVC. With an SR515, which I also have here, it works absolutely without problems and the telemetry also remains constantly active. So it seems to be somehow due to the AVC RX.

[pascallanger]

I have no idea where to look at. I have reports that SR215, SR315 and SR515 are working fine. I've used a SR215 during the dev of this protocol so that's what I would expect.
At this stage and without getting my hands on a SR6xxxx I don't see what I can do...

[Dan0111]

Which country do you live in? I hope there is someone who can send you one to test.

[pascallanger]

I'm located in France.

[IdefixRC]

@pascallanger, happy to chip in for you to purchase one.
@Dan0111 & @ken830, you guys willing to chip in?
If you post a Paypal payme/fund me link here we can see who else is willing to support?

Probably not the cheapest but Amazon France seems to have them here for 92 Euro with free shipping:
https://www.amazon.fr/Spektrum-Radio-Accessoires-SPMSR6200A-Multicolore/dp/B08LF25NQG/ref=sr_1_42_mod_primary_new

Horizon Europe is cheaper but not sure about the shipping costs:
https://www.horizonhobby.de/fr_DE/product/sr6200a-dsmr-6-channel-avc-surface-receiver/SPMSR6200A.html

[ken830]

@IdefixRC, @pascallanger : Absolutely.

[Dan0111]

I am from Germany. Shipping to France and back to me is 30€. I have an SR6200A here that I don't need at the moment. Would that be an option? And when you're done @pascallanger will you send it back to me?

Or if you need to have your own permanently, we can also order a new one for you. Also ok for me.

[pascallanger]

I'm wondering if it would be better if I purchase this 2nd hand DX3+SR6200A so that I have a real DSM radio to play with too that I can look into on top of the receiver. I'm thinking the DX3 is a telemetry capable radio of some sort since it has some SMART battery level indicator but let me know if that's not the case since I don't really know the Spektrum world.
65€ + some shipping:

[IdefixRC]

That might be a good idea.
The DX3 is telemetry capable. With a bluetooth module you can view the data on the spektrum app (I assume it has a serial interface to connect to the BT module which might make it easy to read the telemetry data).
Do send us your paypal link / fund me page and I will chip in.

From the Spektrum website:
It takes only a few simple, affordable upgrades for your DX3 Smart to provide many of the same capabilities as radios that cost much more. Just download the free Spektrum™ Dashboard™ app to your mobile device. Add the BT2000 Bluetooth Module (sold separately) to your transmitter. Then, with no additional sensors or modules, you’ll be able to use the transmitter’s Smart ESC compatibility to receive important telemetry data in real-time, right at your fingertips — and can also set up warning alarms and enjoy new programming options!

[pascallanger]

My paypal account is my email address pascal _ langer @ yahoo . fr (remove the spaces)
I've contacted the vendor to check the availability and shipping cost.

[IdefixRC]

@pascallanger, sent you 40 Euro to contribute.
Hopefully it works out.

[Dan0111]

I have also sent you @pascallanger 40€. Good luck and thank you very much!

[ken830]

I just sent $40... Just want to say thank you for your efforts so far and thank you in advance for your continued efforts.

[ken830]

@pascallanger : while we wait for you to get the Spektrum transmitter and receiver, is there anything we can do on our end to help? I have the DX3 and SR6200A and an oscilloscope with logic analyzer. I don't have an SDR though. Have my eye on the HackRF with the Portapack H4M.

[pascallanger]

You could open the dx3 and look at the RF modulator. I think it would be good to do a dump there if we can.

[jslatten]

The DX3 transmitter and bluetooth module combo is going to be difficult to see and use the telemetry as compared to a dx5 pro, dx5c or dx6c transmitter as it only has limited telemetry through Spektrum's android app...and the android app is pretty crappy. It wouldn't work on the latest android version. Luckily I had a old phone with android 11 where it would
function. <

Edit: It appears that they've updated the Spektrum Dashboard Android app and it now appears to work on the latest Android versions i.e 13, 14, etc.

Also, I was the one who submitted the other issue about inconsistent telemetry. I ended up learning that I can get telemetry fairly consistent when the transmitter and receiver are at a farther distance away from each other. Although it provides slower/less frequent telemetry updates than the Spektrum transmitter, which updates more than once per second compared to multi-module, which updates for me maybe every 5-15 seconds. It's almost as if the transmitter -and multi-module are experiencing RF overload or something from the telemetry transmission when you are too close to the receiver. In any case....make sure you are at least 10-15 feet (3-5 meters) away from your RC vehicle and see if it improves the consistency. I would love for it to work up close like the Spektrum transmitter, however outside of the less frequent updates, the telemetry is usable most of the time. My only other gripe with the Spektrum receiver and Radiomaster Mt12 / Multi-module combo is range seems to be about 2/3 or 1/2 of my Spektrum transmitter + SR315 Receiver.

[jslatten]

Also...I unfortunately caught this thread too late as I have a couple of DX3 transmitters sitting on my shelf that I don't use. I could have offered one up for you.

[pascallanger]

Still waiting for the delivery of the RX + DX3... Should be there Saturday.
I don't care if the DX3 is doing a good job at decoding the telemetry, I only need it to receive it.
Also for DSMR I only have a couple of IDs/RF frequencies. Do you know a RX or can send me a RX that still have a CYRF6936 that I can connect to the SPI? I expect all the recent RXs don't have one so it should be quite old.

[IdefixRC]

Hi @pascallanger did the TX/RX arrive in the meantime and did you manage to take a look yet? Keen to hear what the issue might have been.
Thanks !

[pascallanger]

@IdefixRC I've received the parcel but no time to look into yet. I'm working on multiple protocols at the same time and my personal life also getting in the middle so please be patient ;-)

[IdefixRC]

No worries @pascallanger. Looking forward to hearing what you find. Thanks