Project Overview

Pixel is an interative artwork – a single, 100cm x 100cm pixel.

As you approach the artwork, it glows brighter and brighter, until you are enveloped in a sea of light – up to 18,000 lumens at its peak. When you finally touch the artwork, the light immediately changes to a different color, from a palette of 12 carefully chosen colors. It's impossible to convey the visceral sensation that this experience creates, even with video.

Pixel contains exactly 1024 LEDs - a 32 x 32 grid, inside a 100cm x 100cm frame made from precision-milled corian and MIC-6 aluminum.

The entire glass diffuser is coated with a thin indium-tin oxide layer, which allows for capacitive proximity sensing from up to 2 meters away, and an instantaneous response to touch.

Pixel first sold at auction in 2013 to tumblr founder David Karp for $15,000, and the other five editions have since been sold to other collectors around the world.

My contributions

This artwork was a collaboration between artist Jamie Zigelbaum and our team at Midnight Commercial. I was responsible for designing and implementing the electrical, computational, lighting, and sensing architecture. Highlights include:

• Touch sensing architecture and algorithms, enabling:
  • proximity detection from 2+ meters away, leveraging a custom capacitive sensing algorithm and an actively-driven backplate to cancel out parasitic capacitance from the environment
  • ESD-safe direct touch detection, with protection circuitry to prevent static discharge from damaging the piece
  • FPGA-controlled timing and tuning for LED PWM and capacitive touch sensing to avoid cross-talk and interference.
• FPGA-based PWM dithering algorithm enabling:
  • 100% flicker-free dimming from 0 to 18,000 lumens
  • EMI compatibility with the touch sensing architecture for the piece
  • Zero-noise dimming – no coil hum or capacitor squeal.
  • Calibration and binning of all LEDs in the piece to ensure consistent brightness and color across the entire surface.
• Modular PCB architecture for the piece, incorporating:
  • 64x LED lighting board with 4x4 array of RGB LEDs, LED drivers, and high current edge connectors
  • 8x power and signal distribution boards with carefully-tuned impedance matching for high-speed low-EMI data and smooth power distribution
  • Hybrid FPGA/MCU controller for capacitive sensing, proximity detection, and LED control