Further to my recent experiments with generating and sending WSPR from the Raspberry Pi, reported on this forum, I now have a multi-mode beacon on 40m built around an Arduino (or, at least, around my homebrew Arduino clone, the "WOTDUINO").
The beacon is sending WSPR, FSK-CW, a sort of "Hellschreiber" and a (QRQ) CW ident on a 10 minute cycle.
The beacon is performing well, with particularly strong performance to the US today.
You can read about the WOTDUINO and the DDS Shield I made to host an AD9850 module on my blog: http://m0xpd.blogspot.co.uk/
73 de m0xpd