Reading a Potentiometer — SIK Circuit 2

In this experiment you'll use a potentiometer (a variable resistor with a knob) to control how fast an LED blinks. This introduces analogRead() — reading voltage levels between 0 and 5V as values from 0 to 1023.

Parts Needed

• 1x Arduino Uno + USB cable
• 1x Breadboard
• 1x Potentiometer (10K)
• 1x LED (any color)
• 1x 330Ω Resistor
• 6x Jumper Wires

Wiring Instructions

1. Place the potentiometer in the breadboard. It has three pins.
2. Connect the left pin to GND and the right pin to 5V (or vice versa).
3. Connect the middle pin (wiper) to Analog Pin A0.
4. Place an LED in the breadboard. Connect the positive leg (longer) to Digital Pin 13.
5. Connect the negative leg (shorter) through a 330Ω resistor to GND.
6. Connect the 5V and GND rails on the breadboard to the Arduino.

What You Should See

The LED blinks faster or slower as you turn the potentiometer knob. At one extreme it blinks very fast, at the other it blinks slowly.

Troubleshooting

• Sporadically working: The potentiometer pins may not be making good contact. Press it firmly into the breadboard.
• Not working: Make sure the wiper (middle pin) goes to Analog pin 0, not Digital pin 0.
• LED not lighting: LEDs only work in one direction. Flip it around.

Experiments to Try

• Open the Serial Monitor and print the sensorValue to see the raw numbers (0-1023).
• Use map() to convert the sensor range to a brightness range and control LED brightness with analogWrite().