DJ, may I ask a couple of questions about your schematic? (May I ask them even if I reveal all sorts of ignorance on my part? :)
I'm taking VSX-S3 near the upper right corner as a power supply that converts the line voltage to 5V. Is this some sort of pre-packaged module?
Am I right in thinking that you are detecting the 0 voltage crossover in the AC using U4, and this drives an interrupt?
What is the purpose of J1 -- for expansion, reprogramming, or ??
Finally, I think the MAX6675 is the interface to the thermocouple. Does this IC send the temperature of the probe over a serial interface?
Many thanks for taking pity on this newbie!
Andy
> It's just an MCU with an SPI-based thermocouple chip, LCD, a variable
> resistor, and a power module:
>
> http://www.delorie.com/electronics/laminator/laminator.pdf
>