Hi guys, I've been a bit short of cash and time recently so I thought I would look through my parts bin and find a quick project i could do. I came up with hacking a Loc8tor Lite which i brought about a year ago.
The idea was to turn the Loc8tor into a homing sensor i could fit to a robot so it could follow me around or come find me if i'm not in the room. This was the original plan but i couldn't figure it out then, coming back and looking at the project with fresh eyes it seemed a lot simpler than I first thought.
First i took apart the Loc8tor then disconnected the speaker, then setup a Picaxe 40x2 (just what i had laying about) with a serial screen and servo. The connection to Loc8tor is just a single wire from the speaker + to a pin on the Picaxe (with a 4k7 pull down) with a "count" command counting the audio frequency.
I've tested this at about twenty meters (about 65 feet) and it's still accurate.
Very easy to hack together, simple to program.
I'm very happy with itathe the moment. The next thing is to hook it up to a robot and give it a try.