It hosts a Nordic Semiconductor nRF52832 SoC, ARM Cortex-M4F processor, 64 MHz clock speed, 64 kB of RAM and 512 kB of Flash, built-in Near-Field Comms (NFC), Over-the-Air firmware updates, 12-bit ADC, timers, SPI, I²C, and serial interfaces that can be used on any available pins, plus a temperature sensor.
Williams says that in summary this means the Puck.js can measure rotation (e.g., using the Puck as a control knob), light, temperature, magnetic fields (e.g., magnets used on doors to detect opening and closing or water level via a magnet on a float), can control Infrared devices, and produce any colour light.
Williams says Puck.js is like a development kit that's also a finished product. "You insert a battery, put the case on, and it's a ready-to-go Bluetooth low energy beacon straight-out-the-box with no wires or software required," he adds. "At the same time it's very easy to add new functions and features for home automation projects, IoT prototyping, or education purposes."