Readme
******
1. Please use the Diptrace version 2.2 and above to open/edit the schematic & layout file. 
Newer files are not backward compatible with older version of Diptrace.
2. For hardware version 1.40 and below:
- Please use the MAX6675 Library from Adafruit available from GitHub.
3. For hardware version 1.50 and above:
- Please use the MAX31855 Library from Rocket Scream available from GitHub.
4. For all hardware revision, please use the latest Arduino PID Library written
by Brett Beauregard available for down load GitHub too.
5. Uncomment necessary compiler flag in the sketch for use with different 
hardware revision.