Please see attached Concept drawing.
All my searches on the Internet are with-out success to find something I can use to inject USB - HID data from a Raspberry Pi to the PC.
Currently there exist some Arduino based project, but no general solution.
The purspose of my project would be to
- provide schematic or assembled PCB
- FW for the microcontroller on the bridge
- Protocol description (between uC and Raspi) to inject keyboard and mouse HID data to the PC
- SW lib for the Raspi to use it in C- Programms and common scripting languages
The applications of such board are:
First I would focus on USB-HID profile, later support for other profiles, like filesystem, etc. can be considered.
- use the Raspi to enter e.g. the start-up password for encypted boot harddisk of a remote PC
- Enter text on PC with-out the need of installing any SW on the PC, e.g. remote input or to bridge long distance
- Media control on the PC via Raspi
- the board is supported in parallel to an already installed keyboard, if wanted.
As uC for the USB bridge I consider a PIC32, because I have experiance with the provided SW stack from Microchip, but there might be also alternatives.
* The UART connection is indented for the dta protocol to send USB HID events from Raspi to PC
* The GPIOs are considered as control to switch e.g. between USB HID and UART-transparent mode. Because the board could, as a by-product, also act as USB-UART-bridge between PC and Raspi.
* The SPI connection is indent, if more data is be transfered faster, eg. for later extention where the Raspi could emulated a (encrypted) USB -Stick (e.g. with dynamic filesystem)
Please provide your thoughts in the comments!!!