That’s a good suggestion, but for now I have to stick with the USB type B connector. The injection molded case is already in production, so I can’t change the cutout size now. Also, one supported feature is to power a WiFi adapter through OpenSprinkler’s USB port (http://rayshobby.net/?p=4233), and I worry that a micro USB connector would be too fragile and easy to break if you insert adapter to it.