Kladue, I'm not sure I follow regarding the cold junction reference? Are you suggesting that the TMP513 would cause interference against the PID, or vice versa? Also, when you mentioned that, I thought of another potential draw back. I assume the TMP513 is using the cold junction reference to determine a delta T against the thermocouple? Does that mean if my TMP513 is located inside my control panel, and during the course of a brew day, my control panel changes temperature, that my input will become inaccurate?
Regarding the programming, I've mostly only accomplished the proof of concept against the I2C bus so far. I simply have buttons and textbox outputs to test my I2C interface. My plan is to finish the build, and then spend the next few months working on the programming UI interface. The long term goal is to put the brew rig on the web, allowing me to start a brew day before I leave for work, getting real time updates pushed to my cell phone, and posting Twitter updates at the end of a brew day with the recipe, final gravity, etc. I have some other future thoughts, including managing the fermentation process. So short answer, I do not have any visual controls built at this time.
My development plan is to have all the control logic live within the PC inside my control panel. I will be exposing the entire control process through web services to allow the interface to be written anywhere (web, phone, PC, etc). Which technology set are you using for your C# development? Forms, Silverlight, WPF, other? I assume you are using Visual Studio? 2008, 2010? FYI, a new version of the windows operating system will be out within the next year or two that will run on an ARM processor. This may make our development efforts even easier in the future.