#HITB2021SIN HATS D2 - Building the Ultimate Hacker Badge with Techmaker

### Overview During HITB2021 Singapore (HATS D2), the host spoke with the engineering team from Techmaker to showcase the "ultimate hacker badge" designed for Hack in the Box events, including Cyber Week, Amsterdam, and Singapore. The team developed a modular badge architecture modeled as a "head" and swappable "hats." Instead of producing an entirely new badge for each event, attendees keep a core base board and receive or collect add-on hat boards that expand its capabilities across different conferences.

### Key Topics - **Modular Hardware Architecture**: The base board (the "head") acts as the central compute unit, while plug-in modular boards ("hats") provide application-specific hardware. Physical interconnection uses a standard laptop RAM-style connector to lock the boards firmly in place without play. - **Base Board as an IoT Hacking Target**: Designed conceptually like OWASP Juice Shop but for embedded hardware, the head functions as an interactive IoT learning tool featuring open-source firmware loaded with more than 10 hands-on hacking challenges based on real-world IoT security scenarios. - **Supply Chain and Component Shortages**: The designers detailed how global semiconductor shortages (particularly impacting automotive and microcontrollers like the STM32 family) influenced hardware iterations, component substitutions, and stock reservations, ultimately validating their choice of the ESP32 platform. - **Modular Hat Ecosystem**: Techmaker demonstrated and outlined multiple hat variants, including a CAN bus automotive sniffer, an environmental monitoring hat, and a multimedia/audio hat.

### Technical Details - **Base Hardware**: Built around an ESP32 dual-core microcontroller featuring built-in Wi-Fi, Bluetooth, an onboard antenna, and an additional 8 MB of external RAM suitable for tasks like audio processing. It integrates two round IPS displays (240 pixels each, resembling modern smartwatch screens) positioned as eyes, four capacitive touch buttons, an onboard lithium charging circuit, and an 18650 lithium battery slot for autonomous operation. - **Interconnect Mechanism**: Connects the hat and head using a standard laptop SODIMM/RAM mechanical slot design, allowing hats to partially overlap the round displays for a layered 3D aesthetic while ensuring robust physical stability compared to standard USB or pin headers. - **CAN Bus Hat**: Integrates a CAN bus transceiver and physical wiring connector, functioning as a bridge between an analysis laptop and vehicle networks, UAVs, or robotics using CAN bus. In automotive testing, it allows interacting with internal buses, analyzing traffic passing through security gateways (hardware firewalls isolating infotainment systems from critical vehicle networks), and identifying vulnerabilities in gateway implementations. - **Additional Hats in Development**: - *Environmental Monitoring Hat*: Incorporates a Bosch BME680 sensor to track temperature, barometric pressure, relative humidity, and volatile organic compound (VOC) gas percentages. - *Multimedia Hat*: Features addressable colored LEDs (e.g., for equalizer/disco lighting effects) and microphones equipped with physical hardware kill switches for privacy control.

### Takeaways The Techmaker badge shifts conference badge design away from single-use novelties toward an extensible, multi-event embedded security platform. By combining a resilient ESP32 core, open-source firmware, and mechanically secure SODIMM-based expansion hats, attendees can transition from beginner IoT firmware hacking challenges to hardware-level automotive CAN bus reverse engineering on a single device.