Hi, So i’l start by saying this is my first ‘proper’ FPV Drone and it was bought as BNF but that ended up not working for me so I put in an ELRS reciever. I’m new to all software used so it might be a simple fault, but I can’t find anything online that seems to resolve this.
It was bought as a BetaFPV X-Knight 35 With Caddx Vista and I have added a Radiomaster RP1 Reciever. (Caddx Vista doesn’t support Goggles v2 and FPV Controller 2 on the same firmware version)
FC Board - It’s the V3 model - Link
Radiomaster RP1 - Link
Radiomaster Tx16s with Internal ELRS module
Issue:
I had set what settings I believe are correct in Beta Flight but there is no movement of the controls in the Reciever tab, even though everything appears connected.
Set Up:
- Radio Transmitter and Reciever were updated to ELRS 3.3 with bind phrase used on both via Configurator via WIFI. Reciever flashes on boot and connects when transmitter is on.
- LUA v3 script applied to Tx16s to edit settings.
- In the script screen, Tx16s shows ‘C’ in top right of the screen and I can see the RP1 in ‘other devices’ at the bottom to see its settings.
- I have set the Serial Rx Port in Betaflight as UART 1 as there is only UART 1, UART2 and soft serial available to use. I’m aware the FC connection guide says UART 3, that doesn’t exist in BF. Reciever is soldered to T1 and R1 on the board and T2 and R2 are connected to the Caddx Vista.
- Beta Flight reciever tab has been set as Serial and CRSF, tried with both Telemetry off and on.
- SBUS wire from Caddx Vista to FC board was removed as its not needed anymore (I did start with it connected but found out it can cause the Reciever to go into Boot Loader mode)
Things I have tried already:
- Swapping Rx and Tx cables in case there was a fault here but neither seems make a difference.
- This is the second set of cables I have soldered.
- I have a RP2 which I temporiary soldered in place in case it was a dead reciever but its resulted in the same error.
- All parts were updated to ELRS 3.3 or BF 4.4 in the FC’s case. Maybe this is a problem but seemed the right thing to try.
Pics (maybe these will help):
(Looks shiny as I put conformal coating around the solders when I thought it was all good)
If i missed anythig please let me know. I have been trying for as few days to look at this and i’m getting close to just sending the drone back as it’s not use to me without working controller (Not sure i can but worth a try 
)
Sorry for the long message…
Looking at the photo you’ve supplied and looking at the wiring diagram you’ve soldered your RX to UART2 not 1.
Also make sure to set CRFS as the protocol in the receiver tab 
I think i know why it looks like that.
Mine is the V3 version, sorry there is two FC’s mentioned on that page. V3 has 9 solder points on that edge, V2 has 6.
yes you’re correct it is on UART1
Double check to make sure that TX on the receiver is wired to RX1 on the Flight controller and RX on the receiver is wired to the TX1 on the flight controller.
Have you gone through the binding procedure to bind the RX to the Radio? are you getting a solid green light on the receiver?
I have swapped the wires from opposites (Tx to Rx) to the same (Tx to Tx) as a test in case there was something weird going on and neither showed movement on the controls. I noticed the FC diagram shows it connect as Tx to Tx if you follow the colours so i did try that against what I knew it should be.
The Transmitter and Reciever bind to each other fine. I can see details of the Reciever settings on the Transmitter / Remote screen.
Definitely TX to RX. as the receiver needs to transmit data and the flight controller needs to receive the data and vice versa
If you have a successful bind and Serial RX is set on UART1 and CRSF is set as the protocol in the receiver tab thats all the BF configuration sorted.
Have you created a new model and setup your channels on your radio? making sure that its set to external module as the transmission? as your radio might still be using the internal 4in1.
Also you’re not meant to use UARTs 1 or 3 for RX or GPS! RX should go on 2. Something to do with MSP.
I only have UART 1 and 2. The Caddx Vista is attached to UART 2 so 1 is the only availabe one. I can try resoldering the Vista to 1 if you think it’s that.
I checked the model and its using the Tx16s internal ELRS reciever which is the only one available.
Check to make sure you have mixes setup for your 4 stick controls in the mixes tab also
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Have you been through the setup of your TX16s radio yet? Follow through this guide if you haven’t. Is your radio protocol set to crsf? I dont use elrs but I believe it uses the crsf protocol
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I went through the set up guide and models section again to make sure its all as it should. I can’t see anything a miss there. The mixes appear to be correct for the stick controls, i hadn’t set up the switches yet so I set them up but currently i can’t even see the throttle, roll etc moving in Beta Flight.
Does the flight controller power the RX via USB? if not you’ll need a battery connected to the drone and the usb cable connected to your PC to see the movement in the receiver tab.
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Thats a great shout Deano
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Thats a good shout, it doesn’t power the Receiver from the FC via USB, but I have both USB and battery plugged in when testing once i saw this was true.
Thanks for all the suggestions so far. Maybe it’s a setting i missed. I’ll play around and see if something looks wrong.
Make sure nothing else is enabled on UART1 apart from serial RX.
Also if you press and hold the model key on your TX16S you should be able to select Channel Monitor this will give you a similar view to the receiver tab in BF but this will confirm that your radio is actually sending PWM data to the RX move the sticks and the bars should move on your radio screen.
if they don’t move this issue is with the radio setup and not the BF setup.
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Which area do live in Jason?
Maybe this needs ‘eyes on’ to sort 
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Hi Jason,
Only a quick look - but first photo - Got a better photo of the yellow RX wire
I am counting 10 pads right to left, not 9 in the diagram below ?
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Also to check if you run the ELRS script on the radio it should show a C (for connected) solid in the top right of the screen. Have you checked the bind phrases, and connected to the TX and RX via wifi? They both on the same main version? 2.x or 3.x? I assume 3.x for now!
Have model match, etc off I wouldn’t bother with it (though receiver numbers I’ve now found to be useful!)
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It’s with a sad heart that admit there are many indications that the FC was fried at some point, or a least partially.
I watched a set up guide on Beta Flight and there was some things that I could see in the Guide that just wasn’t happening on my version. It updates the Firmware fine and seems to beep correctly on start up but the were errors of “No Gyro” detected once in Beta Flight that i just thought was things to configure later, not realising i shouldn’t have too. CPU usage at the bottom was far lower then it should be (around 2%) and no Firmware back tracking change these results.
Sorry for the confusion caused with crytic errors. I will make sure it works properly before playing more then I should.
New FC will be here is a few days, Technically better then the fried one above.
BetaFPV F405 4S 20A V5 - Link
Should be simpler to install with connectors instead of solder pads for VTX and Reciever. I’ll update once built… again 
Thanks for the assistance in trying to fix it 
