I recently "killed" two I/O pins, I believe due to a wiring error. I had set up one of the I/O pins as a PWM output to provide a "position" signal to a linear actuator (itself containing some sort of micro-controller). However, I believe that I temporarily connected the linear actuator's position feedback to this I/O pin... The position feedback is a voltage ranging from 0 Vdc to 3.2 Vdc (don't know what the max current output is, but again, it's coming from some other micro-controller). I cannot remember what my I/O PWM output voltage was as the time, but I know that it can be anywhere between 0 Vdc and 5 Vdc. It seems like I effectively connected two dissimilar voltage sources in parallel, with no load - a bad thing, from what I understand. Now, this specific I/O pin, when configured as either a PWM or digital output - does nothing.
Q1: Is there a way to "fix" this? Already tried reloading other sketches to make use of this pin... nothing!
Q2: Any advice on how to prevent damage to I/O pins due to a mistake like this again (other than being more careful)?
Q3: I killed the adjacent I/O pin too (probably when I input the 0 to 3.2 Vdc signal from the motor's micro)... But I had not set it up to do anything within my sketch. Is this also explainable?
Thanks to all in advance.