To use the oven, plug everything in and then turn it on. It will display a splash screen to let you know that the Arduino is turned on and working. To switch between always on mode and timed mode use the rotary switch. When the switch is in its on position it will be in Always On mode, and when off it will be in timed mode. When in timed mode, to start heating press the select button (the middle one) to go to the temperature selection menu. Using the up and down buttons change the temperature values and the left and right buttons switch the cursor between the hundreds, tens, and one value. Once you have selected your desired temperature press the select button to start heating the oven. It will take some trial and error to find the exact temperature that your particular solder melts at, also accounting for any error in the thermistor's calibration. For me my sweet spot temperature is around 215-220 C (measured with the Arduino). Once it hits the set temperature it shuts the oven off and starts the cool down procedure. The cool down procedure is letting the oven cool down to 50 degrees C so that when you take the boards out of the oven the solder isn't still hot and liquid with parts shifting around. When letting the oven cool down, leave the door shut as you don't want to damage the boards with any sudden changes in temperature. You need to let them cool off gradually. Once the oven has reached around 50 C it is safe to remove the boards and finish work on them.

If there is a problem during use shut the box and oven off immediately by hitting the emergency stop and pulling the plug. I have included both the indicator light and emergency stop as a safety precaution since the amount of power going through the relay to power the toaster oven is significantly more than I normally work with. Never leave this unattended when plugged in and running as it has serious potential to start a fire. When using it for the first few times I would keep a close eye on it to make sure that everything is working properly.