In addition to the power switch, each Cricket has a test switch. The behavior of the Cricket unit in each test switch setting is under software control.
Currently, this switch is used when the Cricket runs as a beacon. If the test switch is placed in the ``ON'' position before the Cricket is turned on, it will disable the onboard RS232 chip during start-up, to save energy while running. Even when the onboard RS232 chip is disabled, the Cricket serial port can be accessed using a programming board (see Section 1.3).
To enable the RS-232 chip again, restart the Cricket with the test switch in the OFF position.