Just ordered the OpenSprinkler DC powered version.
I didn’t see any reference to this in the description – can the built-in USB port be used as a power source for the external TP-Link WiFi travel router or should the router be used with its’ own external wall-wart power supply?
As an alternative solution, keep in mind that you can also power OpenSprinkler DC using a USB adapter plugged into the USB port (instead of power adapter that came with the controller). This way, you can use one single USB power adapter with two ports: one port powers the WiFi adapter, and the other power ports OpenSprinkler DC. The circuit is designed such that it can drive sprinkler valves using USB power.