14
CAUTION!
Do not short JP5 and JP6 as you will create a short circuit and you may permanently
damage the battery and other components of the UEPM Development Board.
4.6. Switches
The UEPM Development Board is equipped with three switches:
SW1: main switch. It connects the battery to the input of the regulator. SW1 is
bright red when closed.
SW2 and SW3: enabling switches. They enable the regulator to let the current
flow to power the UEPM Development Board when closed. SW2 and SW3 are in
parallel. SW2 is SPST ON-OFF. SW3 is a momentary SPDT ON-OFF. SW2 is
bright green when SW2 or SW3 is closed.
When the voltage regulator of the UEPM Development Board is powered and enabled
(SW1 & (SW2+SW3)) the LED L2 is bright green.
Moreover, the digital output EN_REG2 of the MSP430 is connected to the enable pin of
the voltage regulator. Hence, after a short impulse on SW3 to allow current flowing
through the voltage regulator and power the MSP430, the latter can set its output
EN_REG2 high to always enable the regulator. Only clearing EN_REG2
programmatically or switching off SW1 will shut down the board. The advantage of this
configuration is that the program of the MSP430 can control when it needs to totally
shut down.
Figure 8
– SW1 and SW2