This system was designed by a group effort of Homeroasters. It uses a customized Arduino and a custom "Juice box"(to measure voltage off the variac). It monitors Time, ET(environmental temperature in the roaster), BT(surface bean temperature), RoR(rate of BT rise/min.) and Juice(voltage from the variac to the main heating element). It uses the custom designed pGesha software program. Here is a link to the hardware and software, tc4
I can hook up to a computer through USB or view on the LCD display.
I'm about to mount the monitoring hardware in a project box.
finish for espresso.