Nate, aka username, shares his SMT reflow oven project using the MSP430. This is also his entry into this month’s Project of the Month Contest. The oven uses a K-type thermocouple for measuring temperature in a $30 Black and Decker toaster oven. His video below goes through the project in detail.
Control over the temperature is somewhat limited due to the response time of the heating elements in comparison to the shortness of the profile. So there really wasn’t any need to run some fancy algorithm cause it wouldn’t have produced much different results. In addition, you don’t want to PWM the relay to much because that would damage the relay contacts switching in/out 1.2KW at a rapid pace. My ultimate goal is to implement a reflow profile without having to hurt my brain nor wallet to much. I simply have a target temp which is the actual reflow profile and then I turn the oven on/off based upon comparing actual temp versus targeted temperature. Ofcourse, the heating elements still radiates after they are turned off so you have to compensate that. Even with the compensation, its still not perfect and you only got 2kb for everything.