Thanks for your answer.
I understand your worry about not documented API.
And I don't understand "IrrigationCaddy" about lost opportunities not openning their product to third party.
Today, open connectivity is half of one product's goodies.
In my case, I would not be able to run Cat5 wire to connect the IP-Sprinkler-control.
I will use an "Ubiquiti Nanostation M2 LoCo". These devices are wonderful. About 50 USD
They can act as wifi client, wifi access point, wifi bridge, etc ...
They are for exterior.
They are POE, so they can be installed more than 50 meters away from the power plug in.
You can build long distance wifi connections. 1 mile, in my case.http://www.ubnt.com/airmax#nanostationmhttp://www.amazon.com/Ubiquiti-Nanostat ... B004EGI3CIhttp://dl.ubnt.com/datasheets/nanostati ... ds_web.pdf
Hey! I don't earn my money selling this devices!
(I am sorry about my bad english)