That is another good idea. Thanks.
On an SGL thread I started on this topic, someone suggested a bit of software which uses a webcam into a PC and does real time light curves, which is brilliant and I think is the solution I’d go for. It needs Adobe Flash and I can only get it to work in FireFox, but otherwise it is very good:
http://www.planetarium-activities.org/shows/sp/lightgrapher
The other thing the SGL thread has raised, which I had thought about and won’t factor into my model, is limb darkening of the distant star. All interesting stuff:
https://stargazerslounge.com/topic/342034-exoplanet-transit-model/
James