On 9/29/05, Damon Hamm wrote: > Goal: To detect the number of people in the room. If you want to be sued by a lot of people than use retroreflective IR or visible laser beams. Anyway if two or more people stay very closed one each other (let say they are kissing toghether) the methode will add one more error. So, one is counting the persons which are passing through a small space and other counting moving persons into an open space. cheers, Vasile > Details: Needs to send a 'count' trigger to a PIC16f628 (which > controls a bunch of solenoids) as people enter and leave a gallery > space (with possible distances up to 30ft). Preferably, there is no > active device on the receiving end and no need to wire anything back > to the main device. This is for a pedestal mounted art device that > will need to be moved and installed in different locations. > > I've been looking at wiring two pen laser elements to beam across at > ankle level to two phototransistors (or photoresistors). I would then > measure the beam break sequence to determine if the person is entering > or leaving. Very prone to error, but absolute precision isn't all > that critical. I am considering using a battery powered box that > would affix to one wall and beam back to the trigger box. Reflecting > the beams back from a mirror seams too hard to calibrate, but I'm open > to ideas. > > Any clever ideas out there? Thanks in advance! > - Damon > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist