It's time to connect the electronics to the CPX, then finish the body by hooking the servo to the front of the cardboard body.

Batteries to CPX

Plug the JST battery connector into the Circuit Playground Express black battery connector.


Tip: If you need to unplug the JST connector, be careful not to pull too hard or the wires may break. Wiggle it gently while sliding it slowly out.

Servo to CPX

The servo has three wires joined to a 3-pin female connector. Plug the male header pins on the ends of the alligator clip wires into this connector. To avoid confusion, choose wires that match the color of the servo wires.

Next, attach the alligator clips to the CPX by clamping them onto these holes around the edge of the board:

  • Connect the red or orange middle wire from the servo to Vout on the CPX
  • Connect the black or brown wire from the servo to GND
  • Connect the yellow wire from the servo to A1

A simple way to remember this:

  • The red/orange wire carries power from the CPX board to the servo. (Vout means "voltage out.")
  • The black/brown wire is the ground wire that completes the circuit so current can flow. (GND means "ground.")
  • The yellow wire will carry the signal from the pin that you program -- in this case, Pin A1 -- so the CPX can tell the servo what to do.

Don't forget, you can remove and reposition the Circuit Playground Express to keep the wires out of the way.

Servo Arm to Front of Inchworm

Unbend a paperclip in the middle and straighten it out. The larger end will go towards the front.


Fold the front and back of the Inchworm together, and mark a spot on the front roughly even with the arm. Insert the larger end of the paperclip through the spot.


Insert the end of the smaller loop through the last hole in the servo arm.


With the paperclip attached at both ends, check to see that the Inchworm is as open as you would like it to be.


Then bend the ends to keep them from slipping out.

This guide was first published on Oct 25, 2018. It was last updated on Mar 08, 2024.

This page (Connect it All Up) was last updated on Mar 08, 2024.

Text editor powered by tinymce.