Wesley Ellis b7ed9adb6c Add initial TOTP watch face impl ...

Vendor code from https://github.com/Netthaw/TOTP-MCU to do the
heavy lifting of computing SHA-1 and HMAC and the rest of TOTP

Also implement a date_time to unix timestamp method

2021-11-22 21:37:21 -05:00

..

TOTP-MCU @ 646474a875

Add initial TOTP watch face impl

2021-11-22 21:37:21 -05:00