"It is often cheaper to manufacture one fully loaded board and only change the cases to limit access," an expert told ...

Eleven of the Nano’s IO pins plus 3.3V and ground are broken out to header pins that stick out of the 3D-printed enclosure, and the dongle is powered over the USB cable. [Nick] also built a ...

That interface doesn’t have to be special, and [Dakhnod] is here to show us that it can be done with an ESP32 microcontroller through its USB interface ... a Bluetooth dongle in this way ...