- The Expressif ESP32-PICO-D4
- The Arduino Nano 33 IoT
Though the first one offered more flash to a lower price, the second one has been chosen by evaluating positively the stability and support of the Arduino products. Moreover, the Nano 33 is slightly smaller than the Expressif board.
A Nano 33 IoT board has been bought, the Arduino IDE has been installed and support to Microchip SAMD based boards has been added as explained here (specifically, the Nano 33 IoT board is based on a Microchip SAMD 21 SoC).
The board pinout is similar to the previous Nano boards as can be checked here. A good getting-started project, based on the ArduinoBLE library, can be checked here. Lastly, though the BLE UUIDs should be defined as private, the list of assigned UUIDs can be checked here.