motion sensor that activates a recording!!!!!

hi I was wondering if anyone could tell me how to build a motion sensor that activates a recording. It would have to be a small unit no more than 3-5 inches. what I would like to build is that when a pereson walks by the unit they activate the sensor and a recording(that has been pre recorded) is played. Any ideas on how to do this??????

randofo9 years ago
Yeah, can think of a couple of ideas. As far as the recording, you can go to Radioshack and buy a sound recorder module for $10 (it will be in the back with the electronic components). The easiest way to get motion activation (since you don't seem to know what you're doing) is to find something that already does motion sensing and then plays a sound or switches on an LED. Then you simply replace their sound or LEDs to trigger your playback device instead. Let me know if you get that far. You may need a relay and/or voltage regulator thrown in there so that one device can propperly trigger the next without frying it.
randofo randofo9 years ago
Oh... and if you find something that does motion sensing and then switches on house lights or an appliance, that is very bad. That means that not only will it not work for what you need it to do because there are dangerous high-voltages involved (that will both destroy the playback module and if you're not careful, yourself).