DEFCON has the most amazing collection of badges that I've seen. Mike's last year article covers all those badges from last year. This being my first DEFCON, we also wanted to make a badge for DEFCON 26. Thus was born the HeartyBadge.

HeartyBadge is simply our popular HeartyPatch single-lead ECG & Heart-rate variability (HRV) monitoring device made into a badge in time for DEFCON 26, where I presented about our HealthyPi open-source patient monitor. We think of HeartyBadge as a ECG and HRV development board, on a badge.

The following are the main features of the HeartyBadge:
* Single-lead ECG monitoring with the MAX30003
* 2 gold-plated pads on the PCB act as electrodes
* ESP32 with PCB antenna supporting Bluetooth & Wi-Fi
* 144 APA102 RGB addressable LEDs (most of them in a matrix)
* On-board Li-Ion battery with charging
* USB for charging, code upload as well as debugging

The basic functionality in the current version of the code is to calculate and send the same HRV parameters as the HeartyPatch over BLE, as well as flash some LEDs in the shape of a heart for each heartbeat detected by the device.

There is a lot more potential for the device in terms of measuring HRV over time as well as deriving stress levels and other information from that data. The LED matrix can allow for display of numbers as well, but the code for driving them has not been written yet.

We will continue adding information as and when available, as soon as we can clean the code up. Meanwhile, checkout our GitHub repo for the code as well as the hardware designs. 

Here is the badge in action in its current form of firmware (it's a GIF with limited frames, so it not very clear)