Queen City Con 0x4 · United States · 2026

Queen City Con 0x4 Badge

nRF52840 LoRa mesh badge in standard, supporter-with-keyboard, and DIY kit versions

The electronic badge family of Queen City Con 0x4, Cincinnati, November 13-15, 2026. The organizers' schematic export covers a triangular standard badge, a supporter badge with a CardKB-style keyboard, and a DIY kit badge, all built around an nRF52840 and an Ai-Thinker Ra-01SH SX1262 LoRa module, with connections for an I2C OLED, a keyboard, and GPS, plus a buzzer and indicator LEDs. The firmware guide notes that fitted parts differ from badge to badge. A third-party design document says the badge ships with Meshtastic, while the Offband MeshCore fork, which the conference organization forked on November 8, 2026, publishes a dedicated QCC Badge companion firmware.

Queen City Con QCC United States Ohio Cincinnati Electronic Badge nRF52840 ProMicro nRF52840 LoRa Ra-01SH SX1262 MeshCore Meshtastic Mesh Network OLED GPS Keyboard CardKB ATmega328PB SAO DIY Kit Supporter Badge EasyEDA North America No Image

EventQueen City Con 0x4

SeriesQueen City Con

Location151 West Fifth Street, Cincinnati, Ohio

CountryUnited States

People

Authors & Credits

conference organizer

Cannon Fodder Security

Named on the official site as the organizer behind Queen City Conference.

Source

schematic author

abend

Named in the Drawn By field of the QCC 0x4 Badges schematic title block.

Source

third-party companion firmware

OffbandMesh

Maintains the MIT-licensed MeshCore fork with the qcc_badge variant, user guide, and QCC Badge release images.

Source

Why It Mattered

It adds a Midwest community-conference LoRa mesh badge whose organizers published schematics, a keyboard firmware, and a printable case during conference week, and whose third-party firmware project documents the board pin by pin.

Hardware

The QCC 0x4 Badges schematic (EasyEDA Pro export, V1.0, drawn by abend, sheets dated February 4 to April 15, 2026) has standard, supporter, supporter keyboard, and DIY badge pages. The standard badge places an nRF52840-QIAA-R on the board with 32 MHz and 32.768 kHz crystals, USB-C, a BQ24075 charger with a charge LED, an XC6220 3.3 V regulator, a PH2.0 battery connector, a power switch, an Ra-01SH LoRa module with RF switch control, a 0.96-inch SSD1306 OLED header, a keyboard port, a four-pin GPS header with a MOSFET ground switch, a buzzer, a user button, and three further LEDs. The supporter and DIY pages both use a ProMicro nRF52840 module with the Ra-01SH, a GPS header, a keyboard port, a SAOv2 header, a buzzer with a MUTE switch, a message LED, and spare GPIO pads. The supporter keyboard page is a separate ATmega328PB board with a CardKB-style key matrix. The Offband design document lists the pin map, a 680k/1M battery divider, a 128x64 OLED on the supporter build, and a diode workaround for ProMicro boards that do not boot on battery. The case repository describes the standard badge as triangular, with a rear battery, an external antenna connector, and an optional LCD header.

Software & Apps

The Offband design document says the badge ships with Meshtastic 2.7.15 built from the nrf52_promicro_diy_tcxo target. Offband, an MIT-licensed MeshCore fork, adds a qcc_badge variant that runs the badge as a BLE companion radio with standalone messaging from the keyboard, a Queen City Con splash screen, Messages, Contacts, Nearby, and Status screens, RTTTL tones with custom tunes, GPS Off/On/Power save modes, and preset channels including #queencitycon. A new badge on that firmware names itself QCC- plus four characters and starts on 919.5 MHz, 500 kHz bandwidth, spreading factor 7. QCC Badge images appear in Offband releases from offband-v1.5.0-beta7 (September 28, 2026) to offband-v1.7.1 (November 10, 2026). QueenCityCon/QCC_0x4_Badge_Keyboard holds the keyboard firmware, modified from M5Stack's CardKB code and flashed over ICSP or a serial header.

Lore

Queen City Conference is a three-day community-run security conference in Cincinnati, organized by Cannon Fodder Security. The 0x4 edition is the conference's fourth year and uses the theme Cleopatra's Cipher, with talks, labs, and villages. The schematic README says the badges were designed in EasyEDA Pro and that the designer will likely switch to KiCad next year so the files sit on an open platform.

Lifecycle

Add-ons & Upgrades

3D-printable case published

Standard badge snap-on case

Snap-on bumper for the triangular standard badge with six retention clips, USB-C and antenna clearances, and standard and comfort fit variants.

Compatibility: Queen City Con 0x4 standard badge.

Source

keyboard add-on design and firmware published

Supporter badge keyboard

A separate ATmega328PB keyboard board for the supporter badge that speaks the CardKB I2C protocol over a HY2.0-4P cable, with firmware modified from M5Stack's CardKB code. With it, the Offband firmware lets the badge compose and send messages on its own.

Compatibility: Queen City Con 0x4 supporter badge; standard badges have a keyboard port.

Source

kit variant schematic published

DIY kit badge

The schematic export includes a DIY badge page built around a ProMicro nRF52840 and an Ra-01SH module. No public source describes how the kit was sold, assembled, or supported at the event.

Compatibility: Queen City Con 0x4.

Source

replacement firmware third-party releases through offband-v1.7.1

Offband QCC Badge companion firmware

MeshCore-based BLE companion firmware with standalone messaging, a QCC splash screen, tones, GPS modes, and preset conference channels, published as QCC_Badge UF2 and DFU images.

Compatibility: Queen City Con 0x4 badges; features depend on the fitted screen, keyboard, buzzer, and GPS.

Source

Operational history

Issues & Camp Impact

event in progress note

The badge was seeded on the first day of the conference from repositories published during conference week. No source yet confirms how many badges of each version were built, sold, or handed out, or how the badge was used at the event.

The record avoids distribution, quantity, and outcome claims until a post-event source exists.

Confidence: official dates
Status: ongoing; completion unverified
Timeframe: first check on 2026-11-13, day one of the November 13-15, 2026 event
Source note: Queen City Conference official site and QueenCityCon GitHub repositories.

firmware provenance gap note

The Offband design document says the badge ships with Meshtastic 2.7.15, while Offband publishes a dedicated QCC Badge companion firmware and the organization forked that repository on November 8, 2026 without changes. No organizer source says which firmware was on the badges handed out.

The record describes both firmwares and does not claim that conference badges ran Offband.

Confidence: third-party design document and releases
Status: open
Timeframe: September 12 to November 13, 2026
Source note: Offband design of record, Offband releases, and the QueenCityCon/qcc-0x4-badge-firmware fork, checked 2026-11-13.

license gap note

The schematic, keyboard firmware, and case repositories carry no license. Only the forked Offband firmware is MIT-licensed. The schematic export is EasyEDA Pro format, and the README says a move to KiCad is likely next year.

The design is public for reference, but reuse terms for the hardware files are unstated.

Confidence: repository metadata
Status: documented limitation
Timeframe: November 2026
Source note: GitHub repository metadata for the three QueenCityCon repositories, checked 2026-11-13.

missing rights-cleared image note

No Queen City Con 0x4 badge image is published. The schematic and case repositories have no license, and the Offband guide's annotated badge photos sit in an MIT code repository without a stated photo licence or attribution for the badge artwork.

The entry remains source-backed and image-free rather than copying repository renders, guide photos, social posts, or screenshots.

Confidence: local project policy
Status: needs licensed original replacement
Timeframe: current catalogue build
Source note: badge.gallery image policy, QueenCityCon repositories, and the Offband QCC badge guide.

Resources

Offband 1.7.1 release firmware release · November 10, 2026 patch release on MeshCore 1.17.0 with QCC_Badge companion and diagnostic UF2 and ZIP images; it fixes LED and display control reporting that was reproduced on a QCC badge. Offband MeshCore firmware third-party firmware repository · MIT-licensed MeshCore fork whose qcc_badge variant runs the badge as a BLE companion radio and whose releases carry QCC Badge UF2 and DFU images. QCC 0x4 Badge Schematics (PDF) schematic PDF · Six-page schematic titled QCC 0x4 Badges, REV 1.0, drawn by abend, with standard badge microcontroller, power and charging, and peripherals pages plus keyboard, supporter, and DIY pages. QCC_0x4-Standard_Badge_Case 3D-printable case · Snap-on protective bumper for the triangular standard badge, published November 4, 2026, with standard and comfort fit variants and print settings. No license is stated. QCC_0x4_Badge_Keyboard keyboard firmware repository · Arduino sketch for the supporter badge keyboard, modified from M5Stack's CardKB code, published November 12, 2026 with no license. Queen City Conference official site official event page · Official site for the November 13-15, 2026 Cincinnati conference at 151 West Fifth Street, with the Cleopatra's Cipher theme, agenda, hotel booking, and a link to the organization's GitHub. QueenCityCon on GitHub official organization repository list · Organizer GitHub organization linked from the official site. It holds the 0x4 badge schematics, keyboard firmware, firmware fork, and case, plus 0x3 badge code and a 0x2 badge backing. Use your QCC badge firmware user guide · Offband user guide for the badge: fitted-part differences, pairing, button and keyboard navigation, screens, default channels, radio defaults, tones, and GPS modes. qcc-0x4-badge-firmware firmware fork · The organization's November 8, 2026 fork of OffbandMesh/meshcore-firmware (MIT). On November 13 it had no commits of its own and sat 39 commits behind upstream. qcc-0x4-badge-schematics badge schematics · EasyEDA Pro project export and schematic PDF, published November 8, 2026 with no license, covering the standard, supporter, supporter keyboard, and DIY kit badges.

Sources

Cannon Fodder Security: Queen City Conference Retrieved 2026-11-13 · Primary event source. It gives the November 13-15, 2026 dates, the 151 West Fifth Street, Cincinnati address, the Cleopatra's Cipher theme, Cannon Fodder Security as organizer, and a link to the QueenCityCon GitHub organization. The rendered page does not describe the badge; the agenda and registration are embedded from Whova and were not reviewed. OffbandMesh (GitHub): Queen City Con 0x4 badge — design of record Retrieved 2026-11-13 · Third-party firmware design document dated September 12, 2026. It describes the badge as a ProMicro nRF52840 with an Ra-01SH, a 128x64 OLED, a CardKB-compatible keyboard, a buzzer, an LED, and an optional GPS port, lists the pin map, and says the stock firmware is Meshtastic 2.7.15 from the nrf52_promicro_diy_tcxo target. It is not an organizer document. OffbandMesh (GitHub): Use your QCC badge and QCC badge radio parameters Retrieved 2026-11-13 · Offband user guide and October 5, 2026 radio note. They document the pyramid and supporter badges, the QCC- device names, the #queencitycon channel, the 919.5 MHz, 500 kHz, SF7 first-boot default chosen for FCC Part 15.247 in the 902-928 MHz band, and that fresh and already-configured badges may sit on different frequencies. The radio note is at https://github.com/OffbandMesh/meshcore-firmware/blob/firmware-base/docs/architecture/2026-10-05-qcc-badge-radio-parameters.md. OffbandMesh (GitHub): OffbandMesh/meshcore-firmware releases Retrieved 2026-11-13 · QCC_Badge companion and diagnostic UF2 and ZIP assets appear in offband-v1.5.0-beta7 (September 28, 2026), offband-v1.6.0-beta1 (October 22), offband-v1.7.0 (November 8), and offband-v1.7.1 (November 10). Release notes do not say which build, if any, was flashed on conference badges. Queen City Con (GitHub): QueenCityCon/qcc-0x4-badge-schematics Retrieved 2026-11-13 · Organizer repository created November 8, 2026. The README says the badges were designed in EasyEDA Pro and that the export and PDF cover the standard, supporter, supporter keyboard, and DIY kit badges. The PDF (six pages, REV 1.0, drawn by abend) shows the nRF52840-QIAA-R standard board with BQ24075 charging, XC6220 regulator, Ra-01SH, SSD1306 OLED, GPS, keyboard, buzzer, and LEDs, and ProMicro-based supporter and DIY boards with SAOv2, MUTE, and spare GPIO pads. It proves the design, not the quantities built or handed out. Queen City Con (GitHub): QueenCityCon/QCC_0x4_Badge_Keyboard and QCC_0x4-Standard_Badge_Case Retrieved 2026-11-13 · Organizer repositories created November 12 and November 4, 2026. The keyboard README credits M5Stack's CardKB code as the base and describes ICSP or serial-header flashing; the case README calls the standard badge the base-tier electronic conference badge and describes its triangular outline, rear battery, antenna connector, and optional LCD header.