Knight Rider LED Chaser with Speed Control

Recreate KITT's iconic front scanner from the TV show Knight Rider — 8 LEDs bouncing back and forth with adjustable speed controlled by a potentiometer. Perfect for learning arrays, loops, and analog input.

KITT:

01 Components Required

🖥️

Arduino Mega 2560

or Arduino Uno*

🔴

8 × LEDs

Red recommended

🔩

8 × Resistors

220Ω each

🎛️

1 × Potentiometer

10kΩ

🧩

Breadboard

Full or half size

🔗

Jumper Wires

Male-to-male

Using Arduino Uno? Change pins 22–36 to available digital pins (e.g., 2–9) and update the array in the code accordingly.

02 Circuit Connection Guide

LED Connections (Arduino Mega)

LED	Arduino Pin	Resistor	Other End
LED 1	22	220Ω in series	Cathode → GND
LED 2	24	220Ω in series	Cathode → GND
LED 3	26	220Ω in series	Cathode → GND
LED 4	28	220Ω in series	Cathode → GND
LED 5	30	220Ω in series	Cathode → GND
LED 6	32	220Ω in series	Cathode → GND
LED 7	34	220Ω in series	Cathode → GND
LED 8	36	220Ω in series	Cathode → GND

Potentiometer Connections

Potentiometer Pin	Connect To	Wire Color
Left Pin	5V	Red
Middle (Wiper)	A0	Yellow / Green
Right Pin	GND	Black

03 Step-by-Step Build Instructions

Set up your breadboard

Place the breadboard on your workspace. Connect the Arduino Mega's 5V rail to the breadboard's positive (+) rail using a red wire, and GND to the negative (–) rail using a black wire.

Place the 8 LEDs

Insert 8 red LEDs across the breadboard with equal spacing. The longer leg (anode, +) goes into one row and the shorter leg (cathode, –) into the adjacent row. Keep all LEDs oriented the same way.

Add 220Ω resistors

Connect a 220Ω resistor between each LED's cathode row and the GND rail. This limits current and protects both the LEDs and the Arduino pins from damage.

Wire LEDs to Arduino pins

Connect each LED's anode row to the corresponding Arduino digital pin: LED1→22, LED2→24, LED3→26, LED4→28, LED5→30, LED6→32, LED7→34, LED8→36 using jumper wires.

Connect the potentiometer

Place the potentiometer on the breadboard. Connect its left pin to 5V, middle wiper to A0, and right pin to GND. This creates a voltage divider that Arduino reads as 0–1023.

Upload the code

Open Arduino IDE, paste the code from Section 05 below, select Board: Arduino Mega 2560 and the correct COM port, then click Upload. All 8 LEDs will flash once to confirm the connections are working.

Test and adjust speed

Watch the KITT scanning effect! Rotate the potentiometer to the left for maximum speed, or to the right to slow the animation down to a crawl (up to ~1 second per LED).

04 How the Code Works

💡

LED Activation

The current LED turns ON, then position moves forward (+1) or backward (–1) based on the direction variable.

🔄

Boundary Detection

When position reaches LED 8 or LED 1, the direction multiplies by –1, reversing the scan automatically.

🎛️

Speed Control

analogRead(A0) returns 0–1023. That value directly becomes the delay() duration in milliseconds — higher = slower.

05 Arduino Code

Arduino C++

// ============================================
// Knight Rider LED Chaser with Speed Control
// MakeMindz.com | wokwi.com/projects/459456978983209985
// ============================================

// Array of LED pin numbers
int led[] = {22, 24, 26, 28, 30, 32, 34, 36};

// Total number of LEDs (auto-calculated)
int number_of_leds = sizeof(led) / sizeof(int);

// Current LED position in the array
int position = 0;

// Movement direction: 1 = forward, -1 = backward
int direction = 1;

// Potentiometer connected to analog pin A0
int potentiometer = A0;

// Stores the potentiometer reading (0–1023)
int potentiometer_value = 0;

void setup() {
  // Set all LED pins as OUTPUT and run a startup test
  for (int i = 0; i < number_of_leds; i++) {
    pinMode(led[i], OUTPUT);
    digitalWrite(led[i], HIGH); // All LEDs ON for 500ms
  }
  delay(500);

  // Turn all LEDs OFF after the test
  for (int i = 0; i < number_of_leds; i++) {
    digitalWrite(led[i], LOW);
  }
}

void loop() {

  // Turn ON the LED at current position
  digitalWrite(led[position], HIGH);

  // Move position forward or backward
  position += direction;

  // Reverse direction at boundaries (first or last LED)
  if (position == number_of_leds - 1 || position == 0) {
    direction *= -1;
  }

  // Turn OFF the next LED (creates the chaser effect)
  digitalWrite(led[position], LOW);

  // Read potentiometer and use as delay (speed control)
  potentiometer_value = analogRead(potentiometer);
  delay(potentiometer_value); // 0ms = fastest, 1023ms = slowest
}

06 Wokwi diagram.json

Paste this into your Wokwi project's diagram.json file to instantly recreate the full circuit layout.

📄 diagram.json — Wokwi Circuit File

{
  "version": 1,
  "author": "MakeMindz",
  "editor": "wokwi",
  "parts": [
    { "type": "wokwi-breadboard", "id": "bb1", "top": -156.6, "left": -198.8, "attrs": {} },
    { "type": "wokwi-arduino-mega", "id": "mega", "top": 58.2, "left": -541.2, "attrs": {} },
    { "type": "wokwi-led", "id": "led1", "top": -42, "left": -169, "attrs": { "color": "red" } },
    { "type": "wokwi-led", "id": "led2", "top": -42, "left": -140.2, "attrs": { "color": "red" } },
    { "type": "wokwi-led", "id": "led3", "top": -42, "left": -111.4, "attrs": { "color": "red" } },
    { "type": "wokwi-led", "id": "led4", "top": -42, "left": -82.6, "attrs": { "color": "red" } },
    { "type": "wokwi-led", "id": "led5", "top": -42, "left": -53.8, "attrs": { "color": "red" } },
    { "type": "wokwi-led", "id": "led6", "top": -42, "left": -25, "attrs": { "color": "red" } },
    { "type": "wokwi-led", "id": "led7", "top": -42, "left": 3.8, "attrs": { "color": "red" } },
    { "type": "wokwi-led", "id": "led8", "top": -42, "left": 32.6, "attrs": { "color": "red" } },
    { "type": "wokwi-resistor", "id": "r1", "top": -72, "left": -173.35, "rotate": 90, "attrs": { "value": "220" } },
    { "type": "wokwi-resistor", "id": "r2", "top": -72, "left": -144.55, "rotate": 90, "attrs": { "value": "220" } },
    { "type": "wokwi-resistor", "id": "r3", "top": -72, "left": -115.75, "rotate": 90, "attrs": { "value": "220" } },
    { "type": "wokwi-resistor", "id": "r4", "top": -72, "left": -86.95, "rotate": 90, "attrs": { "value": "220" } },
    { "type": "wokwi-resistor", "id": "r5", "top": -72, "left": -58.15, "rotate": 90, "attrs": { "value": "220" } },
    { "type": "wokwi-resistor", "id": "r6", "top": -72, "left": -29.35, "rotate": 90, "attrs": { "value": "220" } },
    { "type": "wokwi-resistor", "id": "r7", "top": -72, "left": -0.55, "rotate": 90, "attrs": { "value": "220" } },
    { "type": "wokwi-resistor", "id": "r8", "top": -72, "left": 28.25, "rotate": 90, "attrs": { "value": "220" } },
    { "type": "wokwi-slide-potentiometer", "id": "pot1", "top": 283.4, "left": -308.2, "attrs": { "travelLength": "30" } }
  ],
  "connections": [
    [ "led1:C", "mega:22", "green", [ "v0" ] ],
    [ "led2:C", "mega:24", "green", [ "v0" ] ],
    [ "led3:C", "mega:26", "green", [ "v0" ] ],
    [ "led4:C", "mega:28", "green", [ "v0" ] ],
    [ "led5:C", "mega:30", "green", [ "v0" ] ],
    [ "led6:C", "mega:32", "green", [ "v0" ] ],
    [ "led7:C", "mega:34", "green", [ "v0" ] ],
    [ "led8:C", "mega:36", "green", [ "v0" ] ],
    [ "r1:1", "bb1:tp.2", "green", [ "h0" ] ],
    [ "r2:1", "bb1:tp.5", "green", [ "h0" ] ],
    [ "r3:1", "bb1:tp.7", "green", [ "h0" ] ],
    [ "r4:1", "bb1:tp.10", "green", [ "h0" ] ],
    [ "r5:1", "bb1:tp.12", "green", [ "h0" ] ],
    [ "r6:1", "bb1:tp.15", "green", [ "h0" ] ],
    [ "r7:1", "bb1:tp.17", "green", [ "h0" ] ],
    [ "r8:1", "bb1:tp.20", "green", [ "h0" ] ],
    [ "led1:A", "bb1:4b.j", "", [ "$bb" ] ],
    [ "led1:C", "bb1:3b.j", "", [ "$bb" ] ],
    [ "led2:A", "bb1:7b.j", "", [ "$bb" ] ],
    [ "led2:C", "bb1:6b.j", "", [ "$bb" ] ],
    [ "led3:A", "bb1:10b.j", "", [ "$bb" ] ],
    [ "led3:C", "bb1:9b.j", "", [ "$bb" ] ],
    [ "led4:A", "bb1:13b.j", "", [ "$bb" ] ],
    [ "led4:C", "bb1:12b.j", "", [ "$bb" ] ],
    [ "led5:A", "bb1:16b.j", "", [ "$bb" ] ],
    [ "led5:C", "bb1:15b.j", "", [ "$bb" ] ],
    [ "led6:A", "bb1:19b.j", "", [ "$bb" ] ],
    [ "led6:C", "bb1:18b.j", "", [ "$bb" ] ],
    [ "led7:A", "bb1:22b.j", "", [ "$bb" ] ],
    [ "led7:C", "bb1:21b.j", "", [ "$bb" ] ],
    [ "led8:A", "bb1:25b.j", "", [ "$bb" ] ],
    [ "led8:C", "bb1:24b.j", "", [ "$bb" ] ],
    [ "r1:1", "bb1:4t.b", "", [ "$bb" ] ],
    [ "r1:2", "bb1:4b.f", "", [ "$bb" ] ],
    [ "r2:1", "bb1:7t.b", "", [ "$bb" ] ],
    [ "r2:2", "bb1:7b.f", "", [ "$bb" ] ],
    [ "r3:1", "bb1:10t.b", "", [ "$bb" ] ],
    [ "r3:2", "bb1:10b.f", "", [ "$bb" ] ],
    [ "r4:1", "bb1:13t.b", "", [ "$bb" ] ],
    [ "r4:2", "bb1:13b.f", "", [ "$bb" ] ],
    [ "r5:1", "bb1:16t.b", "", [ "$bb" ] ],
    [ "r5:2", "bb1:16b.f", "", [ "$bb" ] ],
    [ "r6:1", "bb1:19t.b", "", [ "$bb" ] ],
    [ "r6:2", "bb1:19b.f", "", [ "$bb" ] ],
    [ "r7:1", "bb1:22t.b", "", [ "$bb" ] ],
    [ "r7:2", "bb1:22b.f", "", [ "$bb" ] ],
    [ "r8:1", "bb1:25t.b", "", [ "$bb" ] ],
    [ "r8:2", "bb1:25b.f", "", [ "$bb" ] ],
    [ "mega:5V", "bb1:tp.1", "red", [ "v35.7", "h-180.1", "v-422.4", "h326.4", "v-0.3" ] ],
    [ "pot1:VCC", "mega:5V", "red", [ "h0" ] ],
    [ "pot1:SIG", "mega:A0", "green", [ "h0" ] ],
    [ "pot1:GND", "mega:GND.2", "black", [ "v-48", "h-246.55" ] ]
  ],
  "dependencies": {}
}

07 Run the Simulation

Try it instantly — no hardware needed!

Use the free Wokwi simulator to test the Knight Rider effect in your browser. Drag the potentiometer slider to control speed.

✓ No installation ✓ Interactive potentiometer ✓ Real-time LED animation ✓ Free forever

▶ Open Free Simulation on Wokwi

08 Expected Behavior

✓ LEDs scan from left (LED 1) to right (LED 8)
✓ At the last LED, direction reverses automatically
✓ Creates a smooth, continuous bouncing scanning effect
✓ Potentiometer controls animation speed in real time
✓ All 8 LEDs flash once at startup to confirm wiring
✓ Classic Knight Rider KITT front scanner pattern

09 Learning Outcomes

Using arrays for pin management
Understanding direction control logic
Working with analog inputs
Creating non-blocking-style animations
Implementing boundary-based logic reversal
Mapping sensor values to timing

10 Upgrade Ideas

🌟

PWM Fading Trail

Use analogWrite() to create a dimming trail behind the active LED for a smoother glow effect.

🔊

Add KITT Sound

Add a passive buzzer generating a swooping tone that syncs with the LED movement.

🔢

Shift Register (74HC595)

Reduce from 8 Arduino pins to just 3 using a 74HC595 shift register. Great pin-saving technique.

🌈

RGB Knight Rider

Replace single-color LEDs with RGB LEDs and shift through hues as the scanner moves.

⏱️

millis() Instead of delay()

Replace delay() with millis()-based timing to keep the loop non-blocking for additional features.

📺

32×8 LED Matrix

Scale up to a full 32×8 LED matrix scanner for a dramatic large-format display effect.

ROBOTICS

Search This Blog

Arduino Knight Rider LED Chaser with Speed Control - Complete Wokwi Tutorial

Knight Rider LED Chaser with Speed Control

01 Components Required

02 Circuit Connection Guide

LED Connections (Arduino Mega)

Potentiometer Connections

03 Step-by-Step Build Instructions

04 How the Code Works

05 Arduino Code

06 Wokwi diagram.json

07 Run the Simulation

Try it instantly — no hardware needed!

08 Expected Behavior

09 Learning Outcomes

10 Upgrade Ideas

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