Instructions for Light Sensor Learning Kit

I signed up for the Amazon Affiliate program. This gives me a small percentage if someone buys a product through my affiliate link. It doesn't cost the buyer any extra, and I can post a link to any product they sell (except gift cards). This inspired me to put together some easy electronics projects with a list of links so you can build them yourself. 

Last year at the Austin and Floresville Maker Faires, I showed off my "Electronic Pinscreen" project. Here are instructions for how to build your own on a much smaller scale.

To build a smaller version of my LED matrix, you will need 4 LEDs, 4 light sensors, and a battery pack with batteries. While you can buy smaller packages of parts, it's a much better deal to buy them in bulk. For 12 kits, the total price would be around $30.
Now that I'm old enough, I solder all my projects. Maker Faires are a good place to learn how. I went to a class at the Austin Maker Faire a long time ago, and the Kansas City Maker Faire in 2017. But if you don't know how to solder, you can do this project with breadboards instead. Or have the kids twist the wires together and test it, and then have the parents solder it. Lead-free solder would make it safer for kids to handle the finished product. I don't like lead-free solder because it's harder to work with. (Safety note from Mom- soldering should be done in a well-ventilated area on a non-flammable surface that isn't your fancy dining table, with experienced adult supervision because it's over 600 degrees F, and make sure to wash hands afterwards.)

Take two 4" pieces of bare wire, lay them out parallel, about 2 inches apart. Connect all the negative (short legs) of the LEDs to one bare wire. Connect one side of each photocell to the other bare wire. Connect the positive (long leg) of each LED to the other side of each photocell. Connect the red (positive) wire from the battery holder to the bare wire with photocells. Connect the black (negative) wire from the battery holder to the bare wire with the LEDs. It should match the schematic.
Test, and then solder.
You can mount the finished project on cardboard to keep it secure.

Parts list for 12 kits:
uncoated or stripped wire, 8 inches per kit
50 white LEDs http://amzn.to/2Dnzp7G
(20+30) Photoresistors http://amzn.to/2GlVtD1 and http://amzn.to/2GkeqG1
12 Battery Holders (hold 2 AAs each)  http://amzn.to/2p4AUDr

Optional- 2 six-packs of mini breadboards http://amzn.to/2FM5k7e
24 AA Batteries- http://amzn.to/2Hrdn6q