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Using a PIR to turn on a sound module Answered

Hi All,
I have used PIR sensors before but i usually hack one from a cupboard light you can buy.  What I want to do is use a really small (and cheap) board like the trinket (adafruit) and hook it up to the PIR in order to turn on a sound module.  

Does anyone know what board would be best to do this?  All the board will have to do is activate the PIR sensor.  maybe I don't need an actual whole board to get this done?  any clues would be much appreciated.

Discussions

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lonesoulsurferFarmerKJS

Answer 4 years ago

Hey there,
I've tried that before on a project and the PIR sensor only throws out 2-3 volts when activated. I need the sensor to activate the battery's which will be 4.5v

Cheers

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lonesoulsurfersteveastrouk

Answer 4 years ago

The sound card is one you can use in birthday cards. It's really about the sound card though as I want the to use it as a switch to complete the circuit for the power (4.5v)

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steveastrouklonesoulsurfer

Answer 4 years ago

Have you tried wiring the sound module as a load on the PIR ? How do you wire them ?

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lonesoulsurfersteveastrouk

Answer 4 years ago

Not as yet. Still waiting for the sound cards to arrive!

This is how I would be wiring them up:

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lonesoulsurferlonesoulsurfer

Answer 4 years ago

So instead of the LED I would use the sound card. I don't believe that this will work as the PIR doesn't release enough power. so even if I used 4 aa batteries (6v) it has a voltage regulator and only releases 3V

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steveastrouklonesoulsurfer

Answer 4 years ago

In that case, just use a transistor. Put the +ve for the sound card to the battery plus (+ve), put the -ve to the Collector of an NPN transistor, put the base to the PIR, via a 220 Ohm resistor, and put the emitter to the battery (-ve)

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lonesoulsurferFarmerKJS

Answer 4 years ago

Yep tried that as well. I found that the PIR didn't open the relay when it was activated. Maybe the relay I was using operated on a too high a voltage (or I could have wired it up wrong!) might give it another try.