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

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.?

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rickharris4 years ago

Buy a pressure mat

Either use a tape recorder and turn it on with a relay OR use a microprocessor with a voice module to play message

Typical systems can be found in the UK here  You don't say where you are buy radio shack in the USA may carry similiar
mrobyn22 (author)  rickharris4 years ago
I'm sorry, I'm in the US. sell the pressure mat as well - Radio shack should be able to help with the voice recorder and anything else you need.
mrobyn22 (author)  rickharris4 years ago
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.
iceng mrobyn224 years ago
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
frollard4 years ago
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.
iceng4 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.