So the project is finally done other than cleaning up the box and making it look better etc.... The big question though, is, was this project really worth it? How well does this reflow toaster actually work? This is the answer.
This will be a quick write-up about how I did my integer division by 10 and a brief discussion of the main state machine that runs the overall 140-170-215 thermal profile.
Here I discuss the details of me temperature control algorithm as well as some simple interrupt service routines I use to run my communication links (comm. links back to the GUI).
Here is the system demonstration. There isn't really much to discuss in text because the video does a much better job of showing this setup in action. The profile I've developed is a ramp to 140 degrees C with a hold time of 45 seconds once we reach 140. Next, we ramp up to 170 C and hold there for 45 seconds. The last target temperature is 215 C and we hold there for 60 seconds. This last temperature is where things get interesting. Once our hold time expires the system shuts down. These profiles are completely customizable in software (embedded C code in the MSP430).
In this project I took a standard toaster and turned it into a reflow oven. This is the introduction video discussing the system and it's main parts. As discussed in the video, there are four main parts. The first is the GUI or graphical user interface which allows user interaction with the system and outputs data for viewing. Second is an analog interface used to boost the thermalcouple signal as well as the room temperature signal from a microchip MCP9700A. The third part is the embedded digital controller (MSP430G2553 on a launch pad) and last is the power system. Once I got all the bugs worked out and got these parts integrated the system ran very smoothly as you can see in the next post (system demonstration).