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How to attach a flat weight sensor to a voice recorder? What kind of sensor to use and where to buy items? Answered

I'm making a prototype the size of a door mat that when stepped on plays a voice recording. What kind of sensor would I use and how could I make it activate a voice recording (it needs to be flat)? Where might I buy the needed items? The sensor would need to be activated after 1lb of pressure was applied to it.?



Amazon.com sell the pressure mat as well - Radio shack should be able to help with the voice recorder and anything else you need.

Thanks for your help. Another thing I forgot to mention is that the pressure mat would need to be activated by very little pressure...about 2-5 pounds and this mat says 25lbs.

And extreme temperatures, sunlight, moisture etc ?

You can make one that can be operated with finger pressure. A plastic bag.

A piece of card to fit inside with a regular pattern of holes all over it - Round or square doesn't matter.

A length of aluminium cooking foil on the top and bottom slightly smaller than the card - say 1/2 inch all round. Glue to another piece of card nice and flat - Pritt stick works well.

Put card/foil on top and bottom of the card with the holes and tape together round the edges.

Fix a wire to the top and bottom foil using a staple through the card/foil trapping a wire under the staple,

Put in bag seal up

When you press on the card/bag the foils touch through the holes and make the switch. - Very sensitive.

Attach to voice recorder.

We used to make these all the time at school when kids did burglar a;arm projects.

pressure mat.jpg


for example

I'm with everybody on the mat solutions posted above/below...

is there any particular reason it has to be a pressure sensor and not a PIR motion detector or laser trip?

I'm not trying to derail the question, but just clarify why a particular constraint is in place. Often we overlook really simple solutions because we have our mind set on a more difficult solution to the problem.


5 years ago

Insert a piezo-film inside your mat ( do not sew through it  ) just sew around it.
An Op-amp, comparator_IC or microprocessor can detect a cat to a large man.

I have used this material to detect a paintball hit in a vest and disable the
players weapon while ignoring bumps and brush scraping the vest.