Matek405 wing GPS/Telemetry problem

When I try to connect to the matek 405 wing using either Bluetooth or 433mhz radios I have the same problem.

If GPS is connected Mission Planner fails to connect and times out. If I disconnect the the GPS (a BN-880) first, it works every time.

Subsquent to a successful Mission Plannerconnect, if I attach the GPS to the Matek 405 wingwith the power still on, it works. If I disconnect the Mission Planner (with the power still connected to the Matek 405 wing) using the Mission Planner disconnect button and then re-connect it still works.

The same story if I just disconnect the GPS Tx to the Matek board RX and then connect it after telemetry is working, all works.

I’m using TX1/RX1 for the telemetry, TX3/RX3 for the GPS

anybody got any ideas why?

Same issue here. I have not found a solution but since I am using a raspberry pi I just forget about the telemetry radio. No issue when connecting T1 R1 to the Pi for telemetry. Weird.

what exact firmware and bootloader version are you using? there‘s been an issue with bootloader timeout handling with serial periphereals connected and powered, but afaik this has been fixed quite a while ago. it might help flashing the board with current firmware doing full erase and dfu-type reflash using a _with_bl.hex type firmware file.

see for reference.

I loaded the 3.9.10 version of arduplane…I followed Lee Schofields aka Painless360 instructional video on you tube

Yep the bootloader that came on the matek405 wing was not touched…no idea what version it is…is there a way to find out?

I have loaded arduplane 3.9.7 and fixed this problem after seeing a youtube video from Painless360