nrfmicro

Arduino Pro Micro-sized breakout board for E73-2G4M08S1C (nRF52840) modules

Disclaimer

UNTESTED! NOT COMPATIBLE WITH ADAFRUIT FEATHER! NO SOFTWARE!

A double-layer board this size is very limiting so I had to remap GPIO pins to the closest physical positions. I'm still figuring out the best layout and pin options. Supposed to be used with a modified Adafruit Feather nRF52840 Express bootloader.

Downloads

Production-ready Gerber files are in the releases section.

Revisions

Version 0.2 (rev1)

• Added default blue LED at P1.10
• SWO remapped to default P1.00
• DFU remapped to default P1.02
• New mapping for GPIO pins
• Smaller E73 pads (0.65mm)

TODO

• Move DFU pad to the front side (maybe)

Version 0.1 (rev0)

Features

• Same size as a regular Pro Micro
• USB Type-C and MicroUSB support
• Optional LIR2032 holder (BS-7)
• Optional ON/OFF switch (MSK-12C02)
• Optional Crystal (2-pin, 32.768khz)
• Optional Inductor (0805 package, 10uH)
• AP2112K-3.3-based (SOT-23) power switch
• MCP73831-based charger (SOT-23)

Pictures (current version)

References

• Adafruit Feather nRF52840 Express module (see reference schematics there)
• CDEBYTE E73-2G4M08S1C-nRF52840 module ($7.39 on Aliexpress)
• https://github.com/adafruit/Adafruit_nRF52_Bootloader
• https://github.com/jpconstantineau/NRF52-Board
• https://github.com/jpconstantineau/BlueMicro_BLE