Convert USB keyboard to Bluetooth LE

May 23, 2020 ยท View on GitHub

USB Keyboard to BLE converter

Hardware

  • Adafruit Trinket M0
  • USB OTG to host cable or adapter
  • Adafruit Feather nRF52840
  • USB power bank, 5V out
  • USB keyboard
Trinket M0nRF52840
GNDGND
USBUSB
TX (4)RX

Software

Trinket M0

Double click on the Trinket M0 reset. When the TRINKETBOOT USB drive appears, drag and drop the file KBDADVUARTUSBH.ino.trinket_m0.uf2 on the the drive. This programs to the Trinket M0 to act as a USB host for the keyboard. USB keyboard HID reports are send out the UART TX (4) pin. The source code is at https://github.com/gdsports/usbhostcopro.

Feather nRF52840

USBKBDBLE receives HID reports via its UART RX and sends the reports out the BLE keyboard module.