Tutorial about controlling multiple Arduinos via Bluetooth Low Power (BLE) with python multi-threading.
There are no pull-up resistors, because we can use the internal pull-up of Arduino. pinMode(A0, INPUT_PULLUP); int reading = analogRead(A0); Here, 1k / N are used as the load resistor. Actually (200~1k)/N resistor can be used. (lower resistor -> higher detect range).