Using a Breadboard – Simple LED Circuit

As mentioned in my earlier post, I bought a Raspberry Pi 3. I also bought an electronic starter kit to use with it. The kit came with a breadboard, a board used for prototyping circuits. You might find it funny but I did not know how to use a breadboard.

Breadboards come in different sizes and they work the same way. Mine is a full sized (5.5 cm x 17 cm x 1cm) breadboard. Additional breadboards can be attached by the side.

Breadboards are usually used vertically.

Breadboards are usually used vertically.

The columns on the right and left labeled + and – conducts current vertically, every holes in that column is connected. The columns are also isolated from each other (E.g. current will not flow from the positive column to the negative column).
Then, there are numbered rows, each row conducts current horizontally isolated from each other (E.g. current will not flow from row 1 to row 2). The slit/division in the middle separates the rows on the left from the right (E.g. current will not flow from the left row to the right row).

If we want current to flow from Row 1 to Row 10, we use a Male to Male jumper wire. Below is a picture of 2 Jumper wires, the red one is a Male to Male and the blue one is a Female to Male.

Jumper Wires

We will create a simple LED circuit to understand how the breadboard works.

Materials needed:-

  • Breadboard
  • Battery
  • Resistor
  • 2 Jumper Wires (Male on one side to connect on the breadboard)

Led & Resistor

It is a good idea to first design your circuit.

LED Circuit

 

I’m using the Raspberry Pi 3 to supply 3.3V and the 220Ω resistor gives a good output. Led are power hungry devices, to limit the current being drawn, use a resistor. If the LED is not bright enough, use a lower resistance and if the resistor is getting hot, use a higher resistance. On the schematic below, the red wire is connected to a +3.3V power supply and the blue wire is connected a ground (0V).

Breadboard Schematic

Here are some pictures of the circuit.

In this experiment, we did not use any GPIO to control the power by a program. With the GPIO, we could program a blinking LED.

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