Raytac mdbt50 q rx

[pyro9]

Add support for Raytac MDBT50Q - RX USB dongle based on nrf52840.

[hathach]

Thank you for you PR, sorry for the delay. I have been a bit busy with other project. Another note, you need to submit an bootloader PR for this dongle in https://github.com/adafruit/Adafruit_nRF52_Bootloader as well. So that we could update this when new SD come out.

[ladyada]

@hathach please order some dongles from raytac so we can test it out!

[hathach]

@hathach please order some dongles from raytac so we can test it out!

OK, I will order a couple of them.

Update: ordered, It is probably delivered in the next week.

[hathach]

@pyro9 I got the dongle, but don't know how to program or flash it. It comes with raytac firmware, but there is very little information. Would you mind giving me some help here. We will need to get our bootloader on it first, before able to use it with the arduino repo.
https://www.raytac.com/product/ins.php?index_id=89

[pyro9]

@pyro9 I got the dongle, but don't know how to program or flash it. It comes with raytac firmware, but there is very little information. Would you mind giving me some help here. We will need to get our bootloader on it first, before able to use it with the arduino repo.
https://www.raytac.com/product/ins.php?index_id=89

Sorry about the delay getting back to you.
Refer to the datasheet: https://www.raytac.com/download/index.php?index_id=40
Chapter 9, page 21 has drawings showing the layout of the programming pads on the board. I made a programming cradle from a 3D printed part, pogo pins, and the Adafruit programming breakout board and plugged in the J-Link debugger.

I used the bootloader and soft device image for the Feather Express as-is (noting that the DFU button won't work) to get the board up and running, then loaded my software using the Arduino IDE as usual.

I found that Gorilla Glue would not properly adhere the pogo pins to the PLA I printed the cradle from, so I needed to use hot-melt after I soldered leads to the pins.

If you want FreeCAD, step, or stl for the cradle, let me know.

[hathach]

thanks, I guess I have to do a bit of soldering with those pad first, then I will the port for bootloader and check back this PR afterwards.

[hathach]

update: sorry for being late, but I will definitely close this PR this week :)