[Part 2] Arduino Data Logger

• For the external plug pack I selected the POWERTRAN MB8968B from Altronics.  Input is 100-240VAC @ 50-60Hz/0.8A, output is 24VDC @ 1A.
• To produce the 5VDC (from the 24VDC) for the Arduino I selected the Z6334 DC-DC Buck Module from Altronics.  Input is 3-40VDC, output 1.5-35VDC @ 3A maximum (adjusted to provide a 5VDC output).
• To maintain the date and time while the logger is powered off I selected the DS1302 based Real Time Clock Module from Altronics.  Reports online indicate that the DS1302 chip can be unreliable (as opposed to the DS1307) but I have had no issues with the one I purchased.
• The Arduino I selected was one I had already, the Freetronics EtherTen.  The on-board MicroSD slot was the main reason I decided to use this, I didn't require the Ethernet port.