[dafonso] purchased a nice 1500W smoker but was somewhat dismayed that it only had one cooking temperature. To compensate he designed his own PID control system which allows him to set the cooking temperature digitally. At the heart of the system is a PICAXE 18 micro which switches the smoker on and off using a solid state relay. Rather than testing the 110V system on the smoker itself (which would have been a pain indoors) he used a lamp instead. To see if he was getting the correct temperature he taped his thermocouple to the light bulb and let the PID switch the lamp on and off. Also be sure to checkout his video which does a good job of explaining how he was able to solder the surface mount components required for the control board.
[Peter Rauch] has built this meat smoker that has a touch screen control interface. His system is capable of controlling the cooking by monitoring the internal temperature of the smoker as well as the temperature of the meat itself. His touch screen interface allows him to enter his desired parameters and it basically just takes over from that point and texts him when it is done. You’ll have to download the pdf to get to the juicy details of his build, but it is an interesting read.
It looks like he’s using a 4-loop Gefran GFX4 temp controller in conjunction with a Modbus remote terminul interface and a TS8010 HMI touchscreen for the bulk of the electronics. It even has protection limits he can set to keep his family from bumping it up to 1200 degrees.