Here is additional information on the Pigzbe hardware from their whitepaper:
https://pigzbe.com/pdf/pigzbe_whitepaper.pdf"The Pigzbe wallet PCB features Espressif’s ESP32-D2WD, a highly integrated WiFi &
Bluetooth system-on-chip with a dual-core processor and advanced security
features.
At scheduled intervals, the wallet will connect to authorised WiFi networks and poll the
Pigzbe server for notifications, ensuring fully independent operation without a mobile
device present. All connections to the notification server are secured using HTTPS.
System configuration (including the authorisation of new WiFi networks) may be
carried out over Bluetooth from the Pigzbe mobile application. The hardware takes
advantage of LE Secure Connections (introduced in Bluetooth 4.2) to ensure an
authenticated and secure connection between the Pigzbe wallet and the mobile
device, using the LED matrix to support the Numeric Comparison association model.
Two buttons and a 6-axis motion sensor enable interaction with the wallet, while a
miniature speaker, vibration motor and a matrix of 192 LEDs provide engaging and
varied feedback. Ultra low power sleep modes conserve battery life while the device
is not in use.
The Pigzbe wallet is built to meet the needs of users across all age groups. The speed
of the processor allows us to create fluid and engaging animations and audio for
younger children.
When configured as a cold storage wallet for adults, the cryptographic hardware
acceleration offered by the ESP32 allows us to provide industry-leading security
features necessary to safely store and transfer coins.
In all modes of use, the contents of the flash memory are encrypted using AES-256.
All application code must also be signed by the Pigzbe remote server, ensuring that
only trusted software can run on the device. This feature enables us to offer remote
firmware upgrades without compromising the security of the device.
Each component used in the Pigzbe wallet has been selected to ensure reliable,
long-term operation, from the LEDs down to the supporting passive components.
Each electronic prototype is assembled here in London by our experienced design
team, allowing us to rapidly iterate and test new designs before committing to mass
production."