I've been playing with the API for the Irrigation Caddy lately, and I've discovered a few things not listed on the API page.

1) If you broadcast "Discovery: Who is out there?" to port 30303 UDP, all the irrigation caddies on the network will respond with hostname and macaddr.

2) Sending a stop=active will only stop the current zone, not the program.  So far the only way I've found to stop a program is to send a full stop then a full start.

3) The json requests are standard GET's, but all the zone fiddling, start/stop stuff is POST.

Just writing them down here for now so others can find them in the future.