Yeah I really dont know what the heck they did with these small pads. Tested to confirm no continuity on the rx3 pad and dsm pad and no continuity from the sbus pad and the sbus on the big port. Tested the rx3 pad and the sbus pad for continuity throughout the entire board and got no beeps only the dsm pad to the rx3 pin. Really odd. Even cleaned the pads with alcohol to rule out any debris causing the issue. Double checked the rx port for debris and nothing. Would you think bridging a wire from dsm pad to sbus ?

I was in the middle of adding an edit to my last post while you were replying. Can you please check the continuity as described in item #2 of that edit. I'm trying to figure out which breakout pad on the FC the RX3 pin on the MCU is directly connected to. I'm hoping it's that middle RX3 pad.

(04-Oct-2023, 11:48 PM)SnowLeopardFPV Wrote: I was in the middle of adding an edit to my last post while you were replying. Can you please check the continuity as described in item #2 of that edit. I'm trying to figure out which breakout pad on the FC the RX3 pin on the MCU is directly connected to. I'm hoping it's that middle RX3 pad.

Yes I do get continuity from rx3 and that rx3 pin on the mcu

OK, that is some good news at least. I think I am piecing together how it is probably working. The RX3 breakout pad is a direct connection to the RX3 pin on the MCU, and not a direct connection to the RX3 pin the 4-pin socket as I first assumed.

By bridging the RX3 pad to the DSM pad it will give a direct (non-inverted) connection from the RX3 pin on the MCU to the RX3 pin in the 4-pin socket, which is needed for TBS, Spektrum, and ExpressLRS receivers.

By bridging the RX3 pad to the SBUS pad, the RX3 pin from the MCU will instead be routed through a hardware inverter and then out to the RX3 pin in the 4-pin socket. A hardware inverter is needed for FrSky receivers and that is why you will get no direct continuity between the SBUS pad and the RX3 pin in the connector, because the hardware inverter chip in the middle prevents direct continuity.

So I suggest you put a solder bridge across the SBUS and RX3 pads, and then connect the SBUS pad of the XM+ to the RX3 pin of the 4-pin socket as per the BetaFPV wiring diagram. It's not entirely clear if you already tried doing that previously, but do it again for the sake of a sanity check if nothing else.

I haven’t tried soldering directly to the rx3 pin but will do that now and report back !

(05-Oct-2023, 12:24 AM)toiletbae Wrote: I haven’t tried soldering directly to the rx3 pin but will do that now and report back !

Maybe you mis-worded your reply, but I didn't mean solder directly to the MCU RX3 pin. I meant put the SBUS wire from the XM+ back in the plug that connects to the RX3 pin in the 4-pin socket, and then re-apply the solder bridge across the RX3 and SBUS pads.

(05-Oct-2023, 03:16 PM)SnowLeopardFPV Wrote: Maybe you mis-worded your reply, but I didn't mean solder directly to the MCU RX3 pin. I meant put the SBUS wire from the XM+ back in the plug that connects to the RX3 pin in the 4-pin socket, and then re-apply the solder bridge across the RX3 and SBUS pads.

Hi I guess I had already messed up the plug for the plug in port. So I soldered the XM+ sbus wire directly to the rx3 pin and it is now working ! *note soldering directly to the port was a pain in the ass but I managed to do it.

Greatly appreciate all the help snowlepeord ! Please pm me a link I would like to gift some $ for some coffee

I'm glad you eventually got it working even if it did turn into a complete mission. The blame for that can be squarely laid on BetaFPV for having sub-standard documentation which assumes that people know how their hardware has been designed without having a circuit board schematic.

I appreciate the offer, but I don't take money or gifts for helping people out. Any assistance I give to members on here is 100% free