Introduction: Control Snap Circuits With Circuit Playground Express

By Reach and Teach

This is a really short and straight forward instructable particularly if you have already seen some of the other instructables I've posted. But, I know there are a lot of Elenco Snap Circuits kits out there maybe collecting a little dust and this instructable can bring new life to them (even a basic Jr. model) and inspire lots of inventive ideas by inexpensively adding computer control. This is a redux of Computer Control Any Electronic Circuit Kit but is focused in particular on Snap Circuits.

Supplies

2 Snap Circuits Snap-to-Pin cables

170 point breadboard

1K ohm resistor

Clare LCA710 solid state relay

For your convenience, you can get the above items as a Snap Circuits Interface Kit from Reach and Teach for $9.50

Adafruit Circuit Playground Express or other Arduino

Any Snap Circuits project

Misc wire and/or alligator clips

Step 1: Wire Up the Snap Circuits Interface Board

A LCA710 Solid State Relay is a very useful chip for computer controlling a low power circuit. It essentially can be used to replace a switch in any circuit. Simply attach Pad 1 of the Circuit Playground Express to pin 1 of the LCA710 through a 1K resistor. Attach pin 2 of the LCA710 to any Ground (GND) pad of the Circuit Playground Express. In the next step we will make connections to pin 4 and pin 6 of the LCA710. You may want to use a felt pen to color the attachment points on the board as shown so you can easily see where to attach cables.

Step 2: Connect to a Snap Circuits Project

For this instructable, we are using a simple circuit with a motor and LED but you can use any circuit you wish. Snap in the two Snap-to-Pin cables to the terminals of the push button switch. The Snap Circuits Interface board will replace the switch with a Solid State Relay. Attach the pin ends of the two cables to pin 4 and pin 6 of the LCA710 on the interface board.

Step 3: Add Some Code

Check out and download any of the MakeCode examples at: https://shop.reachandteach.com/circuit-playground-express-sample-code or feel free to write your own code. I would recommend starting with Sample Program 0_Rainbow which will cycle Pad 1 of the Circuit Playground Express between digital high and digital low in 3 second intervals. In this case, the motor will turn and the LED will light up for 3 seconds and then turn off for 3 seconds.

Step 4: Congratulations! You're Done

I hope you try this easy hack. Consider the following project challenges:

  • Activate an alarm when someone enters your room or your house
  • Activate an alarm when someone opens a cookie jar to steal a cookie
  • Wire up a radio and have it turn on when the sun rises in your room
  • Sound a chime once every 30 minutes to remind you to stretch your legs when you are sitting down to work
  • Use any infrared (IR) remote control to turn your projects on and off
  • Activate a circuit when you tap a secret code
  • Make a moisture sensor out of a couple of nails and turn on a LED whenever a plant needs watering
  • Make a whack-a-mole, bean bag toss, or other arcade game out of cardboard boxes and foil
  • Play a song using the Circuit Playground Express and use an amplifier circuit to make the music louder.
  • Using the color recognition logic of the Circuit Playground Express, use colored cards to control your circuit
  • Come up with your own ideas and put them in the comments below...

If you want to use your phone or mobile device to control your Snap Circuits projects, check out my instructable: Bluetooth Control With A Web Page. If you want to try experimenting with voice control of your Snap Circuits projects, check out my instructable Getting Started With IoT. Please let me know what you think with your comments.