I like to make a switch between the uart signal lines. The switch should be operated with an output pin of an Arduino.
In this way I want to block or open the serial connection to the Arduino.
Could i use a NPN or PNP transistor and make this into a switch? I wonder if this will work because a the uart signal is only a very small amount of current and most of the time NPN and PNP transistors are used to switch larger loads.
Edit: Ok so i think my below schematic should do what i want. For resistor 2 i would pick a 330ohms? 0.16mah at 5v?
What would i make R1 and anyone any objections?
For as i gather it, if i make the Arduino pin high, it can source current for the circuit and af the TX is high it will make RX high as well.