Laser Pointer controlled flashlight

I am a complete beginner and I know there are these things out there, so please guide me to the right sources!

What I want to do:
Switch a flashlight on and off remotely using a laser pointer. (I have an abundance of zoomable led flashlights at my disposal)

Questions:

  1. Can I power the 3.5v .27A flashlight directly from the arduino without any extra power source (other than the power to the arduino)?

  2. Can I make the entire unit portable by powering the arduino with a 5v 2.1A portable battery charger?
    2a) If so, is it worth it if I want to use it for 4 hours at a time?

  3. Do I even need an arduino to do this?

Thank you in advance!! :slight_smile:

  1. No, the arduino can't handle more than about 0.04A of current. 270mA would fry it quickly. They could both pull from the same power source, but you can't run the power to the flashlight through the Arduino. You'll have to switch it with a transistor or relay.

  2. If it gives clean 5V I don't see why not.

  3. Not really. Seems to me like a phototransistor might be all you need. Maybe an extra transistor, I don't know how much current the pt's can switch. Never used them before.

  1. "DC Current for 3.3V Pin 50 mA" Arduino Uno Rev3 — Arduino Official Store

Delta_G:
3. Not really. Seems to me like a phototransistor might be all you need. Maybe an extra transistor, I don't know how much current the pt's can switch. Never used them before.

Would I be able to toggle the light on and off, or would this simple setup only allow me to turn it off when it was receiving the laser pointer input?

aarg:

  1. "DC Current for 3.3V Pin 50 mA" Arduino Uno Rev3 — Arduino Official Store

I was close. Still a lot less than the 270mA the OP mentioned. I'm going to say I just included a 20% safety factor. Yeah, that's it.

timturben1:
Would I be able to toggle the light on and off, or would this simple setup only allow me to turn it off when it was receiving the laser pointer input?

If you want to toggle it then you might need one or two more components. The Arduino will certainly do it, and may still be the cheapest alternative with as cheap as you can get them these days. But it wouldn't be absolutely necessary.