Looking to spice up your Halloween decorations this year? Learn how to make LED eyes for less than $5 with this beginner electronic project.

This is a fun project that can be completed in an hour. If you have an Arduino starter kit you may already have many of these components, but don’t worry, Arduino is not needed . The end result is a set of battery-powered LED eyes that you can throw at bushes or other objects.

Here’s what they look like in the dark:

Spooky Eyes Result

What you need

  • 2 x 5mm red LEDs ($5.27/50) [ Великобритания ]
  • 1 x 27 ohm resistor ($6.16/100)
  • 3 x AA batteries
  • 1 x SPDT switch ($11.78/20) [ Великобритания ]
  • Assorted heat shrink tubing ($6.29/set) [ Великобритания ]
  • Assorted 7/0.2 jumper wires ($8.99/set) [ Великобритания ]

Spooky Eye Parts

Total cost: $44.44. It’s not even close to $5!

Well, the problem with buying electronic components online is that they become very expensive if you only want one or two. It is a much better choice to buy multiple items. These pieces are enough to make 20 sets of eyes for a total of $2.22 each! You also get spare parts for future projects — always a good thing. Be sure to check out these e-learning websites. these learning sites. these learning sites for more design ideas.


Spooky Eyes Tools

You will need some basic tools for this project. You can get by with tape and cable ties, but that won’t make a very secure connection.

  • wire cutters
  • Pliers
  • Wire stripper
  • solder sucker
  • solder
  • soldering iron
  • «Helping Hands» (UK)

Don’t worry if you don’t know how to solder, we’ve shown you how to get started. You may already have many of these tools and can do without them all, however this is an easy choice and should be the staple of your toolbox.


Spooky Eyes Circuit

This is a simple scheme — do not be afraid of this. Three AA batteries connected successively (one by one). This increases the voltage to 4.5V (each AA battery is 1.5V). Parallel connecting the batteries would increase the current — this is not necessary, since the minimum voltage required to light a single LED is about 1.8-2.4 V, which can provide a little more than one battery.

The resistor is needed to limit the current going to the LEDs. Never connect an LED directly to a power source, it will usually burn out. There is a definite formula for calculating the required resistor (although LEDs often tolerate a small difference). This site is great for calculating what you need. If you want to use more LEDs or a different battery setting, enter the following details:

  • Supply voltage (in this case 4.5 V from 3 x 1.5 V batteries)
  • LED voltage drop — typically between 1.8V and 2.4V
  • Required LED Current — Typically 20mA
  • Number of connected LEDs

The retail stores where you buy LEDs often list these specifications. click, to calculate, to get the resistor value you need.

Finally, the switch simply turns on and turns off chain. You should not use this, although it will save battery life when not in use.

Link it

Spooky Eyes Led Wiring

First, make sure there are no batteries in the battery holders! It can be dangerous to heat the batteries too much. Solder the battery holders together, moving from red to black to red . You should have a red and black cable (one at each end of your chain) «free» for the rest of the chain.

Spooky Eyes Pike

Make sure you cut off a piece of heat shrink tubing and put it on the wire before start of soldering. You want a piece with a diameter slightly larger than your wire — this will give a nice tight bond when heated. Don’t heat up the tube just yet, though.

Creepy eyes shrink

Now solder the resistor to anode (long positive leg) on ​​one of the resistors.

creepy-eyed resistor

Solder red wire from the battery to the resistor. It can be a little tricky to solder directly to the leg components. Make sure your soldering iron tip is nice and clean. This can help to give the component legs a bit if things are complicated. Use a piece of heat shrink tubing long enough to cover the entire resistor, but don’t heat it up just yet.

creepy-eyed resistor

Now solder cathode (short, negative leg) of the LED to the anode of the next LED — you can use a short length of wire for more positioning flexibility when you’re done. Next, solder another wire to the cathode of the second LED — this will go to the switch. Be sure to cut the heat shrink tubing and put it on the wires before soldering, but do not heat yet.

Spooky Eyes Led Wiring

Now solder this wire to average switch connector:

Spooky Eyes Switch

Don’t forget the heat shrink tubing!

Spooky Eyes Switch

Finally, solder the last black wire from the batteries to any of the Switch’s external connectors—it doesn’t matter which one.


Spooky Eyes Led Test

Now, before you heat up all the heat shrink tubing, put in the batteries and make sure everything works. The switch should turn the LEDs on and off, and the wiggle and fragmentation of components should not cause an open circuit.

If the circuit doesn’t work, don’t worry! There are some simple troubleshooting steps you can try:

  • Make sure the batteries are fully charged.
  • Turn on the circuit.
  • Double check that all connections are correct.
  • Double check that the circuit is connected correctly.

If everything works, remove the batteries and heat up the heat shrink tubing. A hair dryer is great for this, although a soldering iron can do the job in a pinch. Be careful when using a hot air gun as the high heat can melt the plastic parts.

You can tie the wires with a small cable tie. Do this with the chain engaged to make sure you are not over-tightening or breaking the chain.

Spooky Eyes cable tie

Now it remains only to adapt it to your project. Here’s what they look like in the dark — pretty cool:

Spooky Eyes Result

Hot glue works well for a strong but not permanent fix, although tape can work just as well.

Now that you’re a soldered ninja, you can move on to more complex projects like these Arduino fights. Take a look at these amazing home decorating ideas and make sure you learn how to sync home lighting and music. — this is amazing!

Have you done anything after studying this lesson? I would like to know in the comments below!

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