Irrigation controller having expansion and pump modules

An irrigation controller which comprises:

• (a) a base unit having logic means for storing and executing an irrigation program with the logic means having sufficient capacity for controlling a plurality of irrigation stations up to a predetermined maximum number of stations, wherein the base unit includes driver and switch means for actuating a predetermined minimum number of irrigation stations which is less than the maximum number of stations which can be controlled by the logic means;
• (b) at least one station expansion module which contains the driver and switch means for an incremental number of stations;
• and
• (c) means for selectively coupling the station module to the base unit to expand the number of stations that can be controlled, wherein the total number of stations controlled by the logic means is the number of stations provided by the driver and switch means on the base unit and the driver and switch means on the stations modules connected to the base unit up to the maximum number of stations.