Since the digital IO pins can be used for I and O Can their direction be changed as necessary to accommodate/emulate a tri-state output?
I have a specific need to either ground the pin's output or let if go to a high impedance so that the device I'm controlling can rise to well above 5V. (I can protect the Arduino pin from unhealthy voltages.) But I need to know if this is a valid use of the pin input/output setting.
And would I need to address the built-in pull-something resistor?
The pinMode function can be used to put pin into a quasi Tri-state mode by setting it to input mode. When mode is set as output then either a high or low can be generated with the digitalWrite function. I believe the best way to ensure that the internal 'soft' pull-up is disabled is to make the output state a low before setting the mode to input.