So, I decided to make something of my own. I was able to build a data logger that transfers temperature data, real time, to my PC or laptop. The next step was to take that data and put it on a graph that also allows you to document different roast stages. Well, as it turns out, the datalogger was the easiest part. The software is a whole other beast. Luckily after much trial and error, I was able to create a very useful program that does just what I want it to.
The goal is to be able to provide my "invention" to anyone for an affordable price. The software was created using an open source programming language, Processing 1.0. Which means that the software program is free and is able to be modified by anyone willing to tackle the language. From there I will be creating a more extensive program to accompany the device, that will be more of what people are used to, as far as user interface. But the bare bones program which I have created, will be more than sufficient to anyone who just wants a window to what they are doing when roasting coffee at home.
As it stands right now, the program graphs the curve of the roast, using 2 temps, the bean temp and environment temp. It uses 2 k-type thermocouples. So if you already have your factory roaster or even a home built roaster, set up with TC's than all you have to do is plug it into my data logger, and voila, you're ready to go. The bean temp and environment temp are displayed, there is a stopwatch that starts, stops and resets the graph. During the roast, the average increase per minute in bean temp is displayed, so you can see the rate of temp change. Also, there are 10 spaces to document the roasting stages. Once each roasting stage is met, you click on the adjacent "button" to record the time and temperature that it was reached and a corresponding dot appears on the graph. After the roast is complete, or when you stop the graph, it can be saved as a PNG image, according to the info typed in the "Roast Title" box.
As I continue to test and modify my project, I will post my progress here. Feel free to contact me to suggest modifications or ask any questions.