I am trying to write a program in Python that will loop to keep checking the serial port (COM4) and print out a message when the character "1" is read from the serial port. I want to send "1" over the serial port from an Arduino gadget upon the push of a button.
However, I get the error "[Error 5]: Access is Denied" when I try to create an instance of a serial object. (It automatically tries to open upon instantiation, which is where the error is, from what I can see from the file in the PySerial package that handles this.)
c = serial.Serial('COM4', 9600)
signal = c.read()
Under Windows, I've always used the port=<int> approach with success.
I.e. change your code to:
c = serial.Serial(3, 9600)