as the titel says: I want a keep the height and footprint of a Seeeduino XIAO as small as possible & retrieving time from the PC over USB.
So the ideal solution for this would be to not add an RTC or any kind of battery but just keeping the supertiny footprint and 4mm flatness of the pure XIAO plug it into an USB-port and the XIAO is receiving actual time from the PC over USB.
Ideally without any special software running on the PC.
The final purpose of all this is to automate a two factor-authentification that uses Time-based One-Time Password algorithm specified in RFC 6238
into a "plug in the physical key" solution.
The time-basing requires actual time as a must. So does somebody know how to retrieve the PC-Time over USB?
I know Of course with deviating from the requirements mentioned above I can do it:
run a partner-software on the PC that uses a serial port to deliver the time-information
using an ESP32 that connects to the WiFi whIch immidiately sets the ESP32's RTC to actual time but how would I make the ESP32 make act like a USB-HID-Device?
increasing the footprint and the height through combining a ESP32 (for retrieving the time over WiFi) with a XIAO to act as the HID-device
- maybe acting the ESP32 is acting as a as a bluetooth-keyboard?
best regards Stefan