Modular and expandable irrigation controller

A method for use with a modular irrigation controller comprising:

• removably connecting an electrical connector of an expansion module having a housing to one of a plurality of expansion module mounting locations of the modular irrigation controller, each expansion module mounting location electrically coupled to a control unit of the modular irrigation controller that executes stored irrigation programs;
• determining, by a microcontroller of the expansion module, that the expansion module has been connected to the one of the plurality of expansion module mounting location;
• and
• transmitting a signal to the control unit to indicate the presence of the expansion module to the control unit.

An expansion module for a modular irrigation controller comprising:

• a housing;
• an electrical connector coupled to the housing and adapted to removably connect to any one of a plurality of expansion module mounting locations of the modular irrigation controller, each expansion module mounting location electrically coupled to a control unit of the modular irrigation controller that executes stored irrigation programs;
• a microcontroller within the housing and coupled to the electrical connector;
• the microcontroller adapted to:
• determine that the expansion module is connected to an expansion module mounting location;
• and
• transmit a signal to the control unit to indicate the presence of the expansion module to the control unit.