Knight Rider Car Strobe Effect

LEDs

Arduino IDE

Arduino Uno Rev3

Breadboard 100x160

220 ohm Resistor

<html><body>This project replicates the iconic LED scanning effect seen on KITT, the talking car from the classic Knight Rider TV series. A row of six LEDs lights up one by one from left to right, then in reverse from right to left, creating a smooth strobe or scanning motion. This creates a visually engaging effect that's great for cosplay props, custom car mods, or learning sequential logic using Arduino. <figure><img src="https://projects.arduinocontent.cc/3d7b9830-f5a9-4a3a-8d94-dba30bb9b387.gif"/><figcaption></figcaption></figure><h3>🧾 Full Code:</h3><pre>int timer = 100; </pre><pre>void setup() { </pre><pre>	 for (int pin = 2; pin &lt; 8; pin++) { </pre><pre>	 pinMode(pin, OUTPUT); </pre><pre>	 } </pre><pre>} </pre><pre>void loop() { </pre><pre>	 for (int pin = 2; pin &lt; 8; pin++) { </pre><pre>	 digitalWrite(pin, HIGH); </pre><pre>	 delay(timer); </pre><pre>	 digitalWrite(pin, LOW); </pre><pre>	 } </pre><pre>	 for (int pin = 7; pin &gt;= 2; pin--) { </pre><pre>	 digitalWrite(pin, HIGH); </pre><pre>	 delay(timer); </pre><pre>	 digitalWrite(pin, LOW); </pre><pre>	 } </pre><pre>} </pre> <pre>int timer = 100; </pre><ol><li>This line declares a variable named timer and sets it to 100 milliseconds. </li><li>It controls the speed of the LED sweep—a delay between turning LEDs on and off. </li><li>You can make the scanner move faster or slower by changing this number. </li></ol> <pre>void setup(){ </pre><pre>for (int pin = 2; pin &lt; 8; pin++) { </pre><pre>	 pinMode(pin, OUTPUT); </pre><pre>} </pre><pre>} </pre><ol><li>This for loop sets digital pins 2 through 7 as output pins using pinMode. </li><li>Why 2 to 7? Because we want to control 6 LEDs on pins 2, 3, 4, 5, 6, and 7. </li><li>The loop starts at pin = 2 and runs while pin &lt; 8, increasing pin by 1 each time. </li></ol><pre>void loop() //contains the two sequences that create the Knight Rider scanning effect. </pre>🔹 Forward Sweep <pre>for (int pin = 2; pin &lt; 8; pin++) { </pre><pre>	 digitalWrite(pin, HIGH); </pre><pre>	 delay(timer); </pre><pre>	 digitalWrite(pin, LOW); </pre><pre>} </pre><ol><li>This loop turns each LED on one by one from pin 2 to 7. This creates a left-to-right animation. </li></ol>🔹 Reverse Sweep <pre>for (int pin = 7; pin &gt;= 2; pin--) { </pre><pre>	 digitalWrite(pin, HIGH); </pre><pre>	 delay(timer); </pre><pre>	 digitalWrite(pin, LOW); </pre><pre>} </pre><ol><li>This loop does the same thing in reverse, from pin 7 down to 2. </li><li>It lights each LED right-to-left, completing the effect. </li><li>The pin-- decreases the pin number each time the loop runs. </li></ol> <h3>⚡Circuit Assembly</h3> <figure><img src="https://projects.arduinocontent.cc/f01a7f4c-14ca-4d52-b383-39f8fe561b13.png"/><figcaption></figcaption></figure> Step 1: Place the LEDs Insert 6 LEDs in a row on the breadboard. Make sure all long legs (anodes) are on the same side (facing right or up). The short legs (cathodes) will be connected to ground through resistors. Step 2: Connect Digital Pins to LEDs Use jumper wires to connect Arduino digital pins 2 to 7 to the anode (long leg) of each LED. Step 3: Add Current-Limiting Resistors Connect a 220Ω resistor to each LED. The resistor can go on either leg of the LED: Before the anode (between the Arduino pin and the long leg), or After the cathode (between the short leg and ground). Electrically, both positions work the same, as the resistor limits the current through the LED either way. Step 4: Ground the GND Rail Use a jumper wire to connect the GND rail on the breadboard to one of the GND pins on the Arduino. Step 5: Upload and Test Plug your Arduino into your computer with a USB cable and upload the Knight Rider code. ✅ Circuit Check <ol><li>Before powering up, double-check: </li><li>All LED anodes are connected to digital pins. </li><li>All LED cathodes go through a resistor to GND. </li><li>Nothing is shorted. </li><li>You’re using 220Ω or similar resistors. </li></ol></body></html>