That would be a valid complaint if it was a commercial product, but since it's just a journal article I think they just designed it however was convenient for t

That would be a valid complaint if it was a commercial product, but since it's just a journal article I think they just designed it however was convenient for them. Also, this way it seems like they could just connect an off-the-shelf sensor part with a usb c connector and call it a day, rather than having to connect the sensor to a esp8266, display, and battery.