I am trying to switch GND to a signal line by using an NPN as a switch.
I want node A to be tristated so that it is driven by another signal coming to A from another device or A should go to GND.
This is why I am thinking of using a transistor switch.
I am using 10K as the base resistance to drive it into hard saturation. I am controlling the base voltage through an AVR. However when I measure the voltage at node A, I am getting about 0.6V. I understand that I will never get 0V even if the transistor is in saturation. Will this work?
Any other ideas would be appreciated.