On 09/02/2010 06:06 PM, Ted Hayes wrote:

I would think that the accuracy of such an approach would be *severely* limited by the framerate of the webcam.

You're right. I was already willing to assume that the maximum expected RPM would be lower than the camera's fps, but you're making me realise that limit would be much lower than that.

Why can't you use a hall effect or reed switch or photointerrupter and arduino?

I can. I just had the crazy idea that the camera approach MAY be easier, or a little bit more difficult but cheaper. It's been a long time since I last touched an electronic circuit :)

Also, I'm helping a friend of mine with an installation, and she's at some hundreds km from here, so I need something that I can try here and she can then replicate there.

So my idea was to simplify the hardware at the cost of complicating the software a little bit. However I'm afraid the trade-off is not reasonable enough :)

Thanks m.