A led chaser with only one pin. 3 pins, to bee exact, including all ground and Vcc connections.

Step 1: Collect Your Components

4017 IC

Arduino

10 LEDs

220 ohm resistor

wires

breadboard

Step 2: Connections

Pin 14 of 4017 to Pin 13 of Arduino

Pin 8 to GND

Pin 16 to 5V

Pin 3 of 4017 to positive of LED1

Pin 2 of 4017 to positive of LED2

Pin 4 of 4017 to positive of LED3

Pin 7 of 4017 to positive of LED4

Pin 10 of 4017 to positive of LED5

Pin 1 of 4017 to positive of LED6

Pin 5 of 4017 to positive of LED7

Pin 6 of 4017 to positive of LED8

Pin 9 of 4017 to positive of LED9

Pin 11 of 4017 to positive of LED10

Negatives of LEDs to GND via 220 ohm resistor

Pin 5 of 4017 to pin 8 of 4017

Pin 13 of 4017 to pin 8 of 4017

pin 15 of 4017 to pin 8 of 4017

Step 3: Code

//Copy and paste this code to Arduino.

void setup() {
// put your setup code here, to run once:

pinMode(13, OUTPUT);

}

void loop() { // put your main code here, to run repeatedly:

digitalWrite(13, HIGH);

delay(100);

digitalWrite(13, LOW);

delay(100);

}

Step 4: DONE!!!

Led chaser with only one pin.

Step 5: Troubleshooting

LEDs inserted backwards: Reverse the leads.

IC inserted backwards: Pull it out and reverse the leads.

Faulty connections: Press everything in the breadboard. If that didn`t work, look for wiring mistakes.

Code not uploaded: Upload the code to Arduino.

Step 6: How It Works

the arduino gives a clock signal to the 4017. every time the 4017 is energized and deenergized, the 4017 turns the first output off and the sec0nd one on. then the arduino gives a second clock signal and the 4017 turns the second output off and the th1rd one on. this happens to till the 10th output is one and then the 4017 goes back to the 1st output. a 555 timer can also be used to make the clock signal.