GGtag Is a Reusable, Reprogrammable ePaper-Based Badge with RFID

Almost everyone in a shared office wears a plastic identification badge and an RFID-based access card. And conferences notoriously give attendees one-time use paper-based badges. As a reprogrammable solution, networking equipment company Eurolan has introduced a reference platform that combines those functions into an electronic option. GGtag is an ePaper badge with programmable RFID. And it can be programmed with a mobile device via a web app and sound!

GGtag's main feature is the 3.52" ePaper display driven by an RP2040 microcontroller. A second microcontroller, a Microchip ATtiny85, emulates RFID tags using a firmware called avrfid. A single coin cell battery, or USB, powers the entire badge. This combination of features makes GGTag ideal for shared workspaces or even as a reusable conference badge.

There are two ways to program it. The first is straightforward: it is via USB. An alternative method, however, uses a PDM microphone for audio-based programming.

GGtag uses a library called ggwave to send data via sound. It is an FSK-based protocol with transmission speeds up to 16 bytes per second while using error correction codes. One advantage of this method is that you can program multiple GGTags simultaneously.

A web-based interface allows you to design the e-paper badge with text, icons, and images. Then you can use it to program a GGtag with either method. Almost any mobile device can be an audio programmer by playing the encoded sound stream. For USB/serial programming, your web browser must support the Web Serial API (such as Chrome on desktop and Android.)

The GGtag design files are open source and available in a GitHub repository. It has the schematic as a PDF, PCB as gerbers, and several demo badges. Soon documentation will also be there, but currently, only an outline is available.

Eurolan has a Crowd Supply campaign for GGtag in the preliminary stage. Visit that page to join a mailing list to know when the campaign goes live.