- Adafruit Trinket M0
- USB OTG to host cable or adapter
- Adafruit Feather nRF52840
- USB power bank, 5V out
- USB keyboard
| Trinket M0 | nRF52840 |
|---|---|
| GND | GND |
| USB | USB |
| TX (4) | RX |
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.
USBKBDBLE receives HID reports via its UART RX and sends the reports out the BLE keyboard module.