Build the Turtle Bot

Circuit Build

CPB to Crickit

Connect the six hex standoffs to the Cricket as shown, using the screws fitted through the back of the board. Finger tight is fine, you don't need to crank them down too hard and risk damage to the board!

Then, set the Circuit Playground Bluefruit on top of the board with the shown orientation -- The Crickit DC power jack points north and the CPB USB port points north.  (You may reverse both directions if you are in Australia.)

Motors to Crickit

Next, plug the motor wires into the Crickit's Motor 1 and Motor 2 ports

  • Left motor goes to Motor 1 port
  • Right motor goes to Motor 2 port
  • Follow the pictures for black and red wire assignments -- getting this backwards isn't a big deal, because it can always be reversed in software!

Moar Powaaaarrr!

The final thing we'll need is a way to provide power. The Crickit would like to have 5VDC at 1A available for all of its duties, including powering the CPB and driving the motors.

The 5V USB phone-charger style battery is perfect, except for one thing -- how to connect it?

Thankfully, the USB Type-A to 2.1mm center positive cable is just the thing! Plug the USB end into the battery and the barrel plug into the Crickit's barrel jack.

Here's the final circuit ready to go!

Chassis

Form the Chassis

A piece of corrugated cardboard is perfect for building your turtle bot chassis!

Draw some guides for cutting your chassis -- it doesn't have to match this one exactly, just so long as there's room for the parts you can get creative with it!

Looking through the rest of this page will give you an idea of the size needed for proper parts placement.

Use a hobby knife or scissors to cut the chassis to shape

Attach Motors

Use double stick foam tape to connect the motors to the underside of the chassis

Keep them straight and even with each other -- the cart will drive straighter than if they're offset.

Add Wheels

Place the big honkin orange wheels onto the motor shafts as shown!

Optional Bumper

This step is optional, but you may find it helpful. You can add a cardboard bumper to the front of the bumper bot so that it won't accidentally drive over lower obstacles that are cleared by the chassis.

Cut a length of cardboard that is a bit wider than the cart chassis and that reaches from the front down about 3/4 of the way to the ground

Bend the cardboard to fit the curve of your cart's front

Glue the joint and then connect the two pieces, holding them in place while the glue cures

Turtle Decoration

Cut out the body of the turtle from some EVA foam or green felt as shown.

Bonus points for eye stickers, googly eyes, or draw or paint on your own creation!

Use the wheels as a guide, tracing around them to create a pair of cutouts as shown here.

You can use double stick tape or another adhesive to affix the turtle pattern to the cardboard chassis.

Attach Crickit

Use adhesive-backed Velcro tape to attach the CPB/Crickit board sandwich on top of the turtle layer.

Route the power cable up through a wheel well and attach the battery underneath, between the motors, using some double-stick foam tape or Velcro.

Flippers

Add to the charm of your little robot friend with some flipper feet! If you elect to add these flippers, simply trim off the back feet from the green foam/felt.

Draw out a flipper shape on some EVA foam and cut it out with scissors or a hobby knife.

Use some hot glue to affix the flipper to one of the wheel hubs as shown.

Repeat this step for the other side.

Our turtle is ready for coding!

This guide was first published on Nov 12, 2019. It was last updated on Nov 12, 2019. This page (Build the Turtle Bot) was last updated on May 09, 2020.