I found this post entitled
Putting your EM-406 GPS back in to NMEA mode without waiting
at http://diydrones.com/profiles/blogs/put … e=activity, it may prove useful to someone.
It does work, provided you send the commands to the SiRF chip at the baud rate it was programmed with previously … try different baud rates if it doesn’t work for you.
By the way, you can find the SiRF Binary Protocol manual at http://www.usglobalsat.com/downloads/Si … otocol.pdf