Wearable Electronic Conference Badge. It contains color-changing RGB LEDs, a display, 3D printed conference holder, and lanyard.
The C3 is similar to the ESP32 - but uses RISC V as a core, not Tensilica, and has Bluetooth LE (not classic!)
An easy to use Arduino library to send and receive messages between IoT devices (such as the ESP32's or Arduino devices) when using the Texas Instruments CC1101 Low-Power Sub-1GHz RF Transceiver