When I started building my $27 EKG, I just assumed there would be an excellent library to chart the output to the screen in a compelling and useful way. There are a couple of libraries that are pretty good, but they are either really old, have bad open source licenses, are not fast enough (we need to eat a lot of data in real time) or they do not do exactly what we want. It is a little bit of a hassle to write something like this when in a rush, but it could not be helped. That is what I did most of the day yesterday. I hope to have the thing all up and running in the next few days. It will be useful to have an unencumbered library for a lot of the things we want to do with this little project and probably for future projects, too, so it is not a loss.