Hardware Overview

Our reconstruction of the card10 badge consists of three things:

The two boards are connected via a board to board connector and then screwed together with M2 screws. The wristband is attached to back of the Fundamental Board with two clamps.

Harmonic Board prototype top side

General Properties

Weight ~ 19 g
Size Height (without wristband): ~8-9 mm. Width: 38 mm. Length: 45 mm
Display ST7735 0.96” Full Color IPS LCD (80x160)
RGB LEDs 11 RGB LEDs facing up, 4 RGB LEDs facing down (SK9822-2020)
Wirstband GPIOs 2 GPIOs + GND + Power per side
Battery capacity 200 mAh (prototypes: 100-150 mAh)
CPU MAX32666 (dual core Cortex-M4F at 96 MHz)
RAM 512 kB
Flash 1 MB internal + 8 MB external
Accelerometer BMA400
Sensor fusion BHI160 (accelerometer + gyroscope + sensor fusion)
Magnetometer BMM150
Environmental sensor BME680 (temperature, rel. humidity, air pressure, air quality)
ECG MAX30001
Pulse sensor MAX86150 (with second ECG channel)
Ambient light sensor 940 nm IR LED attached to ADC


card10 reconstruction prototype

More information to come.

Fundamental Board

The Fundamental Board is located just above the wristband; above it comes the battery, the Harmonic Board, and the display. The Harmonic Board is connected to the Fundamental Board via a board to board connector.

Several interfaces for interhacktions are included on the Fundamental Board. The travelers can be alerted to an event using the vibration motor. Screws through the ECG contacts are used both for attaching the wristband and for making contact with your skin for ECG measurements. Besides its use for interhacktions, the USB-C connector is also used for charging the battery and for updating the firmware.

A PDF version of the schematic of the Fundamental Board is available here


Fundamental Board prototype: Fundamental Board prototype

Harmonic Board

The Harmonic Board sits on top of the Fundamental Board. It contains most of the user interface and a few sensors.

A PDF version of the schematic of the Harmonic Board is available here

Harmonic Board prototype top side: landmarks

Harmonic Board prototype top side

Harmonic Board prototype bottom side: landmarks

Harmonic Board prototype bottom side