Connectors should be used to electrically connect an embedded controller to batteries or other DC (direct current) sources. If on board switching is needed a switch should also be included.
For embedded controllers that do not need a lot of current, a typical connector is a connector that is spaced out by 0.1 inches. This type of connector is inexpensive, and it can also be used (in jumper mode) as a switch.
An inexpensive controller can use one 1x2 SIL 0.1 inches header as the connector to a power source. Another one can be used as a switch. Note that the switch should be on the unregulated side of the regulator.