I have cobbled together several devices for triggering remote cameras, based on a Passive Infrared Receiver. Briefly, the PIR, which is designed to sense a passer-by and turn on six white LEDs for a few seconds to illuminate a stairway or whatever, has one of the LEDs replaced with a connection to an analogue-to-digital input of a Picaxe. The Picaxe program waits until the passer-by (in this case a wild lyrebird singing and displaying on his performance mound ) triggers the PIR and takes photographs every five seconds for one minute. After the minute, the Picaxe program tries again, the assumption being that if the bird is still performing, the PIR will pick him up again. Not so. What happens is that the bird stands stock still for up to twenty minutes and doesn't trigger the PIR again until he leaves. Our only photographic record of his memorabloe performance is the first minute after he arrives, and a brief shot of his retreating backside as he leaves. But all the time he is there he is singing, and deafeningly. So what I need is a signal from a microphone. I have programmed the Picaxe to recognise a level, however fleeting, of 1.5Volts from the PIR, and I'd like to add to the existing setup a similar, ~1.5Volts from a microphone. Just a voltage. No attempt to reproduce the actual sound. I would need some kind of level control, in order to adjust the output to respond to the target bird's close-up song and not respond to his rivals who are some distance away and nowhere near as loud. I have looked at a kit for a voice-controlled microphone which would probably work but needs 12Volts worth of batteries. I need at least four of these devices and possibly eight, so they must be cheap. I feel that there must be a simple way to achieve this. On past experience, if there is a simple answer, this is the newsgroup where I will find it. Can anyone help?
- posted
14 years ago