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ECE 1100 · GEORGIA TECH · SUMMER 2026

Desktop Room Control Panel

A desk knob that controls the light behind my monitor.

An Arduino Nano reads a potentiometer and drives a MOSFET to dim an LED strip. A room-control concept, narrowed down to one working feature.

01 / SCOPE

The Idea

  • Original pitch: a desktop control panel with switches, knobs, and indicator LEDs for managing parts of my room, such as lighting and window curtains
  • Given the time left in the semester, narrowed the pitch to one feature: a knob that controls the brightness of an LED strip mounted behind my monitor
02 / COMPONENTS

Key Parts

  • Arduino Nano: a small microcontroller board that runs the code and controls the other components
  • Potentiometer: a knob that changes its voltage output as you turn it
  • MOSFET: an electronic switch that lets a small signal control a much larger flow of power
  • PWM (pulse-width modulation): switching power on and off very quickly; fast enough switching looks like smooth dimming instead of flicker
  • Breadboard: a board for wiring circuits together without soldering
  • USB pigtail cables: short USB cables with bare wire ends for connecting into the MOSFET's screw terminals
03 / BUILD

The Progress

  • The circuit has two sides: a low-power side that reads a potentiometer, and a high-power side that runs the LED strip off a wall charger through a MOSFET
  • A microcontroller pin (max. 40mA, avg. 20mA) cannot supply enough current to power an LED strip (approx. 100mA - 3A) on its own, so the MOSFET sits between the Nano's control signal and the strip's power source
Arduino Nano seated across the center trench of a breadboard
The Nano placed across the breadboard's center trench, keeping its two rows of pins electrically separate.
Arduino Nano and potentiometer wired on a breadboard
The potentiometer's outer pins tied into the breadboard's power rails, with its middle pin wired straight to the Nano's A0 input.
MOSFET driver module with red and black power wires attached
The MOSFET's input side wired to the wall charger, before the output side was connected to the LED strip.
  • Wired the potentiometer to 5V, ground, and an analog input pin, and the MOSFET's control pins to ground and a PWM output pin
  • Firmware reads the potentiometer's position, turns it into a PWM signal, and sends that to the MOSFET, which sets the strip's brightness
Completed breadboard circuit with Nano, potentiometer, MOSFET, and jumper wires
The full breadboard circuit: Nano, potentiometer, and MOSFET all wired together.
04 / TROUBLESHOOTING

Successes and Failures

  • MOSFET signal pins: bare through-holes instead of screw terminals. I bent each jumper wire through two of the three holes for PWM and ground so it would hook onto the module. Shaping the wires securely was harder than expected.
  • "Not dimmable" LED strip: the listing said the strip was not dimmable, which refers to standard voltage dimmers. The PWM switching method I used works fine.
  • Clone-board bootloader: the Nano is an ELEGOO clone. A troubleshooting source told me to select the older "ATmega328P (Old Bootloader)" option, but that made every upload fail; switching to the standard, newer bootloader setting is what actually fixed it.
  • Unstable brightness: the strip pulsed brighter about twice a second at lower settings, pointing to a noisy signal rather than a bad strip. Fixed by reseating a loose ground connection and adding a digital low-pass filter, the software equivalent of an RC low-pass filter. Each update keeps 90% of the previous smoothed value and adds 10% of the latest reading.
  • Reversed knob direction: turning the knob dimmed the strip backward from what felt intuitive. Fixed in software by reversing the output mapping instead of rewiring the potentiometer.
  • Success: the core wiring, including the potentiometer input and the high-power charger-to-strip path, worked as planned on the first attempt.
05 / RESULT

The Outcome

  • Turning the knob smoothly raises and lowers the LED strip's brightness in real time, with no visible flicker or lag
  • Still a breadboard prototype with exposed wiring, not a finished enclosure
Monitor setup with the LED strip turned off
Before: no ambient lighting behind the monitor.
Warm LED strip glowing behind a monitor
After: the strip lit at knob-controlled brightness.
Turning the knob changes the LED brightness in real time.
06 / LEARNING

ECE Skills Gained

  • Reading analog sensor input and converting it to a control signal
  • Using a MOSFET as a switch so a low-power signal can control a higher-power load
  • Wiring and powering a circuit on a breadboard, including grounding
  • Filtering noisy sensor data in software
  • Uploading and debugging firmware on non-standard hardware
07 / REFLECTION

Final Thoughts

  • Narrowing the scope was the right call: I ended up with one finished, working feature instead of an unfinished multi-feature panel
  • The hands-on troubleshooting made Computer Engineering coursework feel more concrete: reading a sensor, picking the right component, and watching code change something physical
  • Would like to keep building: add the switches and indicator LEDs from the original pitch once I am more comfortable soldering, and possibly the curtain-control feature