Latest update April 6, 2013 - William Phelps - wm (at) usa.net
Updates in v130406wm
06apr13 - fix error in Auto DST for southern hemisphere
Updates in v121105wm
05nov12 - fix bugs in Auto DST code
Change Makefile to support atmega328p
NOTE: This version will probably not fit on a 168p with all features enabled!
Updates in v121012wm
12oct12 - fix set volume low/high
06oct12 - fix Auto DST in southern hemisphere
27sep12 - add support for 9600 bps gps
28aug12 - fix check for space in gps buffer (string null term)
Changes to run on Atmega328p
Interrupt names
Rewrite of GPS code
Better error checking, including CRC check
GPS error counters visible in menu
Improvements to GPS support
GPS Enable/Disable in Menu
GPS Lat & Long displayed in Menu
Rewrite of Auto DST so it works with GPS
DST update now works regardless of when clock is powered on
update occurs once per minute if clock is powered up "cold" with DST active
DST change will occur next time Seconds = "00"
DST Rules in Menu (read code before changing!)
Changes to Auto Dim feature
lo and hi brightness values in menu
use 20k ohm resistor
menu option to show ADC and Brightness values (press select button to update display)
Added Progressive Alarm feature
alarm starts out with single beep at long(ish) interval
more beeps, shorter interval as time elapses
Includes Drift Correction & Seconds Dial features from jsgf (by request)
Added Last Digit Brightness Boost (LDBB)
for vfd tubes with dim right most digit
Added #IFDEF for GPS support (user request)