The PSM is powered by either the USB connection (5V supplied by the USB host or powered HUB) or a standard 5.5mm OD/2.1mm ID barrel connector with 4-9 VDC.  The regulator can provide up to 500 mA of 3.3 VDC power.  USB power is protected from overcurrent by a resettable fuse.  There is no protection with barrel connection and you must be careful not to draw more than 500 mA.
	The PSM itself draws about 135 mA with the backlight on at full intensity.  The PSM current draw is only ~35 mA with the backlight off.
	The FTDI FT232RL manages the USB connection.  It is configured for 5V logic in order to control the 5V power it can provide to the PSM.  But, there is also a 3.3 V output of the FTDI chip.  This is provided on the pin with the circle around it just above and to the left of the mini-USB connector shown in the photo above.
	There is a small proto area between the min-USB and 5.5 mm barrel connectors.  The hole with the circle around it, just above the barrel connector, is connected directly to the barrel connector power pin.  So, you can add a larger capacitor on this input voltage if you desire using this area.
	Note that all holes with square pads on this board are ground.