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Topic: Fan that knows where you are? (Read 1 time) previous topic - next topic


Actually, PIR should work if you use 2 PIR sensors, and arrange them so there is a small
overlap of their receptive fields - out at the edge. Then, you will have a "binocular"
system with 2 wide peripheral pickup areas [approx 120 deg each, depending on the
sensors], and a common area of 10-degrees or so where the edges overlap.

When you walk into the room, one of the 2 sensors will pick you up, and the servo (I
presume there's a servo) will pan over until both PIRs are picking you up. Then, as you
move it will continue to follow you (you will write good s.w. for this, I presume).

Once it's locked on, it will stay locked on. If someone else enters the room, it won't
budge, as long as it's already locked on (assuming the s.w. is written this way).

I've done this, it works. My robot could track me out to 20-feet or so. These are the
sensors I used, AMP PIRM 180-200, although bought years ago and elsewhere,

or something else from here,


Sounds like a good plan.  I have one PIR now that I got for testing even before I had this idea.  I could get a second quickly.

Would you be willing to share the sketch you wrote to follow you this way?  Perhaps submit as a library?

Thanks. 8)
Love to tinker on all kinds of stuff. Visit my site to see what other projects I have going on.


As I recall, I did this 5 years ago using PIC software, but it's simple enough
to gin up. Just read the 2 PIRs and do some if...thens. The important thing
is adjusting the PIR receptive fields. Mine was easy to do, since the units
I used had essentially horizontal pickup patterns, rather than 2D patterns.


Sounds good.  As a former alarm company owner I am familiar with masking PIR's to control their field of view.  I would mask these to a horizontal fan only a few degrees "thick" across the room to avoid lights or anything else that might cause noise.

I will probably be a bit before I start this...right now I am working on extracting an engine from a welder for use on a hovercraft.

( Oh ... and I still have a web company to attend to when I have spare time !  :smiley-mr-green:
Love to tinker on all kinds of stuff. Visit my site to see what other projects I have going on.

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