Adding a loud buzzer/alarm to a photon

Does anyone know of a buzzer/alarm that can be connected to a photon to provide a very loud noise to sound when a thermcouple sensor reads a certain value?

You could use a piezo buzzer. Alternatively, use a siren and enable that using a relay/mosfet.

Do you have any examples of sirens I could use? Or ways to hook them up?

That’d depend on how loud you’d want it to be. If you browse around the forums and/or Hackster for a bit, you ought to find plenty examples.

I used this for a project once. https://www.sparkfun.com/products/7950
Wasn’t super earsplitting, but was loud enough.

Note that the 35mA spec exceeds the 25mA limit on the GPIO pins. I connected it directly anyway, and it worked and didn’t burn up that pin on my Photon. I did it because:

  • I didn’t send a continuous tone, but beeped it on and off
  • 3.3V is slightly less than the 3.5V rated voltage, so I figured it would consume a bit less than 35mA
  • The 35mA is a max rating, and it probably consumes a little less

Anyway, don’t blame me if you burn up that pin on your Photon.

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