Jonathan Diamond's PCB Map Hides an LED Matrix for Lighting-Based Location, Route Tracking

Software and electrical engineer Jonathan Diamond has designed a printed circuit board that acts as a family location map — using the PCB itself as a display, with roads picked out in copper traces.

"I like using constraints as inspiration, and I wanted to build something that took advantage of the PCB medium itself," Diamond explains of the project's inspiration. "While I knew I wanted the PCB itself to be the centerpiece, I went through a long list of ideas before settling on one. My default instinct for an interesting display project is always to turn it into a clock. In the end, the most interesting direction was a display that reflected the daily rhythms of my family in real time."

Inspired by Chai Jia Xun's PCB Metro Map project, Diamond's design is a map — albeit an artistic one, provided by the online service Snazzy Maps and converted into a smooth vector. After layering and vectorization, the map was turned into a circuit design in KiCad: "The roads became a top-side copper layer," Diamond explains. "The land+roads image became a top-side solder mask layer. The flipped land+roads image became a bottom-side solder mask layer. Separately, I created another KiCad project for the actual electronics: the [Espressif] ESP32 development board, LED matrix interface, and power connectors."

The LED matrix was chosen as a simpler route to interactive lighting than populating the board itself with LEDs. Positioned beneath the PCB, the matrix is lit according to MQTT messages received by the Espressif ESP32 microcontroller over its Wi-Fi connection. Python-based desktop software can provide the current locations of family members and routes for their travel, which are plotted onto the LED matrix and shine through the bare sections of the board — or the panel can be used to display graphics or text, too.

More information on the project is available on Diamond's website, with hardware design files and source code available on GitHub under an unspecified open source license. "In addition to showing the route to events," the maker adds of potential improvements to the map, "I could have some indicator that an event start time is coming."