Cumulative exposure meter for long duration exposures

Hi all!

This will be where I'll document my exposure meter project using the tsl 230R light sensor. It is based around an 8-bit 18f series pic micro, the previously mentioned light sensor, currently uses 6 buttons and a 4x20 lcd.

The goal of this light meter is to aid with the proper exposure of large pinhole cameras. I should state now that I am not a photographer. I don't even own a camera besides the one in my phone. I am a computer scientist and computer engineer working on this project in my spare time for some friends because I find it interesting. Anyway, the problem with long duration exposures is that varying light levels can make it very difficult to calculate proper exposure. This is epically true outdoors on partly cloudy days.

This project, which I have yet to come up with a clever name for, will address the issue by sampling light levels at 1 second intervals and continuously adjust the exposure time. Currently, I'm working to eliminate some bugs in calculating lux and exposure times but its getting closer by the day. Many thanks to Chris for the example code and a place to document the project.

Look for more in the coming days but feel free to ask questions if you can't wait that long!

-Jason