ARDUINO-OATH-TOKEN
==================

This is a basic Open-Source implementation of a TOTP (compliant with OATH*) code in Arduino.
Basicaly it generates 6 digits OTP based in a EPOCH time from RTC. The OTP is updated each 30 seconds.

http://www.youtube.com/watch?v=lXXYWbGGlBU

For HMAC-SHA1 hash this implementation uses the code from Cathedrow / Cryptosuite (https://github.com/Cathedrow/Cryptosuite). 
However a small change was added to sha1.h and sha1.c: The method size_t Sha1Class::writebytes(const uint8_t* data, int length)

For debug purposes the main important functions are printed to serial output.

A picture of a working prototype can be found at: 
https://github.com/damico/ARDUINO-OATH-TOKEN/blob/master/arduino-oath-token-prototype.png

*http://www.openauthentication.org/

author: Jose (Ricardo de Oliveira) Damico (jd dot comment at gmail dot com)