No, I did try that but it was too slow. I will write up an article once I have improved it if people are interested in. In a nutshell, I take a stream of frame

No, I did try that but it was too slow. I will write up an article once I have improved it if people are interested in. In a nutshell, I take a stream of frames from the camera, then do a diff on the frames to see what has moved, I then see if the diff of pixels over time is what I'd expect a pushup to look like using basic logic. The movement of pixels over time should look similar to a sine wave. I threw in some simple logic to account for noise in the data.