Controllers for optically switchable devices

A method for determining leakage current information, the method comprising:

• (a) determining, via a first current meter of a window controller, a current provided to a first IGU operatively coupled to the window controller via a first electrical pathway;
• (b) determining, via a second current meter of the window controller, a return current from the first IGU that returns to the window controller via a second electrical pathway;
• (c) comparing the current provided to the return current to form a comparison;
• and
• (d) determining leakage current information associated with a wire of the first electrical pathway and/or a wire of the second electrical pathway based at least in part on the comparison.

A window controller for controlling multiple optically switchable devices, the window controller comprising:

• a plurality of insulated glass unit (IGU) controllers, each configured to control an IGU of a plurality of IGUs operatively coupled to the window controller;
• and
• a processing unit configured to control each of the plurality of IGU controllers, wherein each IGU controller is configured to:
• receive, while in a sleep mode, a tint command to transition a tint of an IGU operatively coupled to the IGU controller,
• responsive to receiving the tint command, awaken from the sleep mode and transmit instructions to one or more peripheral components to cause the tint transition to occur, and
• after transmitting the instructions to the one or more peripheral components,
• return to the sleep mode such that the IGU controller is in the sleep mode while the one or more peripheral components cause the tint transition to occur.