Challenge Five | Build a Robot! (v2)


  • Put all your skills together to build a robot with two light sensors that control two motors, gearboxes and wheels.


  • 1x Arduino microcontroller,
  • 1x breadboard,
  • 1x piezo buzzer,
  • 2x light sensors,
  • 2x motor & gearbox sets

(To learn more visit )


This is where it all comes together: we’re controlling motors and gearboxes with our light sensors so that our robot can begin to think and move for itself.


For complete visual instructions, click here.

  1. We’re going to replace our light sensor-controlled L.E.D.s with light sensor-controlled motors. The two light sensors will be our robot’s ‘eyes’.
  2. Transistors allow us to control a larger voltage (9v) with a smaller voltage (5v from our Arduino). We’ll use them to turn our motors on and off. Place the transistors in the breadboard using B1, 2 & 3 and I1, 2 & 3 (Fig.2). The transistors should be back to back with the metal sides facing each other but not touching. This is important.

    Transistors correctly placed into the breadboard

    Transistors correctly placed into the breadboard

  3. Now connect the motors up. Remove the L.E.D.s and put them into A20 and A22, with the short legs in the black power rail again. Put the red jumpers from one motor into the red power rail, and the blue jumper into B1. Repeat for the second motor, this time using I1 for the blue jumper. Use the green M-M jumpers to connect A21 to A1 and A23 to I3. Put the green jumpers from the light sensors into A0 and A1 if they’re not there already. The black jumper join A3 and I1 to the black power rail. If everything’s connected correctly, when you turn the 9v battery on, your motors will move!

    Click the image for detailed instructions

  4. Download this sketch: Zombiebots_Challenge Five v2, open it and upload it to your Arduino.

You will use these skills later by:

Saving humankind from Zombies!

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