Spynet Laser Trip Wire

Product Information

The batteries are mounted in individual AA battery holders. The three battery holders are soldered together in series and the end leads are soldered to the circuit board.

Breadboard hookup wire kit (only a few needed for this tutorial but the set is good for an electronics kit) The diagram depicts a breadboard and GPIO breakout for illustrative purposes, but feel free to just connect a ground pin and pin 21 with a jumper wire on the Raspberry Pi.

Program the Arduino

Create a new .NET Console App using either the .NET CLI or Visual Studio. Name it InputTutorial. dotnet new console -o InputTutorial A using declaration creates an instance of GpioController. The using declaration ensures the object is disposed and hardware resources are released properly. This tutorial shows you how to construct a laser tripwire that plays an alarm when the laser is interrupted. It uses a photoresistor to sense the presence of a laser beam and use a standard piezo element to play sound straight from an Arduino without an amplifier. Deploy the app to the SBC as a self-contained app. For instructions, see Deploy .NET apps to Raspberry Pi. Make sure to give the executable execute permission using chmod +x.

The main power buses on the breadboard are regulated. Unregulated power from the power adapter goes into the power regulator on the Arduino An LDR (also known as a photocell) is a special type of electrical resistor whose resistance is very high when it’s dark, but reduced when light is shining on it. With the Raspberry Pi turned off, place your LDR into the breadboard, then add the capacitor. Push the code to the Arduino with the following steps. Ensure the switch on the breadboard is set to off so the device does not start bombarding you with alerts as soon as the code is uploaded.

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There are many great ways to build on this project and make it even more cool while learning about electronics. Try changing the melody that plays when triggered or building a case for the device that allows you to mount it to the wall.

This is my first time using the fancy switches etc in the DLC. Thanks to some ideas from another thread, I placed the big powered roll up door from the factory across the roadway at Sanctuary. I set a laser tripwire to cut power to it whan triggered by enemies only. That closes the door. Anything that is not hostile will not trigger the tripwire. Carla can come and go with no problem. But, after an enemy triggers the tripwire, it does not reset. You must cycle power to the tripwire to reset it and open the door again. I am looking to see if a non-mod way can cycle the power after some time.

This laser tripwire project is a great introduction to digital making with a Raspberry Pi and breadboard circuit.