The Arduino/TC4 is an interesting option for those that do not worry much about handling electronics without a case. The TC4 is a 4-channel temperature probe shield that can be attached to the standard Arduino UNO open-hardware device. There is also an integrated product that combines a variant of the UNO with the TC4 in one package, named TC4C. Furthermore, the HT Roaster Interface was developed as add on to the TC4/TC4C stack to allow the control of the Hottop home roaster via serial commands that can be assigned to sliders or buttons in Artisan (see this post for details).

Artisan implements the serial protocol of the Arduino TC4/TC4C with PID support.

Watch out! Older TC4 firmware versions operated at the lower 19200 baudrate.