2026-05-12 (Tu) SubdermalDuino Arduino support

I read up on the nRF52840, starting with Sparkfun and their documentation, which led me to Adafruit. I followed the instructions to write the bootloader, but it failed, even though it said that it finished. The instructions told me to enter bootloader mode by pressing a button or jumpering DFU to GND, but I had to track down the pinout to realize that I was supposed to use RST (reset), which is the DFU pin. Once I accessed that mode, I discovered that my board used a recent enough bootloader that I could drag-and-drop to update, which went smoothly. I also found out that the boards I ordered were a clone of the nice!nano keyboard controller. I uploaded a "Blink" program, but I could not tell if it worked because I was unsure which pin had the onboard LED. I tried uploading a program with a print() function, but the board stopped responding.

Set up to talk with a board

The rest of the posts for this project have been arranged by date.
First time here?

Completed projects from year 1
Completed projects from year 2
Completed projects from year 3
Completed projects from year 4
Completed projects from year 5
Completed projects from year 6
Completed projects from year 7
Completed projects from year 8
Completed projects from year 9
Completed projects from year 10
Completed projects from year 11
Completed projects from year 12

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2026-05-12