Activity #2: A Bright Idea. Light up an LED by wiring a circuit with a breadboard.

Learn to build circuits with several different kinds of components on a breadboard.

STEP #1

Gather your supplies. For this activity, you will need:

  • 2 AAA Batteries

  • 1 Battery Holder

  • 1 DC Motor

  • 1 LED (Light Emitting Diode)

  • 1 Button 

  • 1 Red Wire (Male to Male Connector)

  • 1 Black Wire (Male to Male Connector)

  • 1 Wire in color of your choice (Male to Male Connector)

  • 1 Resistor

  • 1 Breadboard

  • Insert two AAA batteries into the battery holder. REMINDER: Make sure that the flat end of the battery matches up with the negative (-) end of the battery holder, and the end with a bump matches up with the positive (+) end of the battery holder.

Get an LED to light up on a breadboard.

STEP #2

Connect the red and black wires to the wires on the battery holder. Connect red to red and black to black. 

STEP #3

So many wires! It may be helpful to review the “Wires” component card before completing this step.

STEP #4

Plug the wires into the breadboard. For this step, plug the red wire into a hole, or socket, on the positive (+)  side of the long row along the side of the breadboard. Plug the black wire into the hole next to it that is labeled as negative (-) 

Breadboard? I thought this was a robotics kit, not a cooking class. - Review the “Breadboard” component card to get a better idea of what is happening in this step (and the following steps, too!).

STEP #5

Insert the two wires from the LED into two separate sockets on the breadboard. The shorter wire is the negative side of the component and should go into a socket on the negative row. The longer wire is the positive side of the component and should go into the positive row.

Why is one leg longer than the other? - Check out the “LED” component card to find out what is going on and how LEDs work.

If the LED lights up, CONGRATS!

You have successfully created a circuit using a breadboard! 

If your LED doesn’t light up, here are a few ideas to try:

  • Check to make sure the switch on the battery case is flipped to the “on” position.

  • Make sure that the wire legs of the LED are not in the same long row of sockets. 

  • Turn the LED around and insert the wire legs into the opposite sockets.

  • What happens if you turn the LED legs 90 degrees so that they both fit into sockets in the same row? 

  • What happens if you add in more LEDs in the rows?

STEP #6

Follow this diagram to build a circuit on the breadboard using the power source, an LED, and a resistor

Troubleshoot your circuit:

If you don't get the LED to light up at first, try these possible solutions.

  • Is the electric current passing through the LED in the right direction? Flip it around to test it.

  • Are both legs of the LED touching in the same row? If so, the current will take the easier path through the metal clip and will not go through the LED at all. Make sure that each leg of the LED is touching a different metal clip inside the breadboard.

  • Is there a continuous circuit with no gaps? Trace the flow of electricity from the battery, through the metal clips, through the components, and back to the battery. Electricity can’t jump from one metal clip to another. It must go through a wire or another component to get to the next clip. Think of it like a connect-the-dots picture you may have drawn when you were younger. Every component must be connected to the next.

Can you draw a diagram of this circuit?

Take a look at the “Breadboard” component card. You can use the circuit diagram on the card as an example, but your diagram should include the resistor, as well as the LED.

Add a button to your breadboard circuit. Follow this diagram to build a circuit on the breadboard using the power source, an LED, a resistor and a button. The LED should light up when you press the button down.

STEP #7

Button, button. Who’s got the button? Check out the “Button” component card to figure out what is going on and how it works. 

If the LED does not light up, use the troubleshooting tips from step #6.

STEP #8

Create a breadboard circuit with a DC motor, button, and a power supply. Troubleshoot using the same solutions as in previous steps. 

Wait! How does that work again? - If you need a review of how the DC motor works, you can go back to the “DC Motor” component card

Sketch a diagram of your circuit. Be sure to include all of the components.

Put it all together. Build a single breadboard circuit using a power supply, resistor, LED,  DC motor and a button!

STEP #9

Remember to troubleshoot using the tips in earlier steps!

Why do this activity?

  • Learn how to include components such as LEDs, switches, and resistors in an electrical circuit.

    • As you get comfortable with using the different components you can get more creative in your robot designs. 

  • Figure out how a breadboard can be used to build a circuit as another step towards building your own robot.  

    • As you build your own robot you’ll learn that your power source can only supply so much energy. As you design your robot you’ll have to use design thinking to make choices that bring your ideas to life.