In this tutorial, eight LEDs are interfaced to the Arduino Uno board. This is not complicated – it is just like interfacing a single LED to the Arduino as done in tutorial 3, but eight times over. A program is then loaded to the Arduino that will turn the eight LEDs into a “Knight rider” display.
The following video shows what you will achieve:
Can’t see the video? View on YouTube →
Prerequisites
You will need to have completed tutorial 3 and its prerequisites before attempting this tutorial.
Components
Besides a breadboard, Arduino Uno and USB cable, you will need:
| Qty | Part | Designator | Notes | Type |
|---|---|---|---|---|
| 8 | 470 ohm resistor (yellow – violet – brown) | R1 | 1/4W, 5% or better | Resistors |
| 8 | 5mm red LED | D1 | Other coloured and sized LEDs could also be used, e.g. 3mm green LED | Semiconductors |
| 9 | Wire links | Wire links that will reach from the breadboard to the Arduino | Wire |
Circuit Diagram
The circuit diagram is shown below. It is simply eight LEDs interfaced to the Arduino pins 2 to 9.
Building the Circuit
Place the LEDs next to each other in the breadboard so that the anode (longer lead) is at the left and the cathode is on the right.
Insert the 470 ohm resistors connecting one lead to the LED’s cathode and the other to the top rail.
Join the anodes of the LEDs to pins 2 to 9 of the Arduino from left to right using single-core wire. Join the top rail to one of the GND pins of the Arduino.
For more detail: Arduino Knight Rider
