I have been talking about this for ages… threatening to build it… even ordered parts. But, it wasn’t until a couple of weeks ago when Drew brought his Sansaire over and cooked some eggs for us that I finally got the motivation to start work on this project.
There are 101 ways you could do this. I’m going for cheap. My temperature sensor is a super-cheap PT100 PTC sensor. I am running it in a wheatstone bridge connected to a differential amplifier tuned to get the best resolution out of the temperature range I’m interested in. (49C – 74C) The output of that goes to a Nano clone, which currently only turns a Solid State Relay on and off. (I plan to use PID in the future) The relay turns a slow cooker on and off. This tiny one really isn’t hot enough, but I’m giving it a try today.
I am monitoring the whole thing over the USB/Serial port with a quickly hacked together windows application. Future plans including adjusting the setpoint and tuning the PID from this application.
So, in about an hour, I should have some perfectly cooked eggs!
UPDATE:
It worked! These were cooked to 64.5C for one hour.
