The serial port must be over USB cable, from the phone to a computer.
In Java, I got it working by using the following code:
CommConnection comm = (CommConnection)Connector.open("comm:USB1");
// Now use comm to read and write data
How can I do this in Python for mobiles, specifically PyS60?
I got this from here:
import pys60usb
usb = pys60usb.USBConnection()
# Connect to port 1. Works with most S60 3rd devices.
usb.connect( port = 1, mode = pys60usb.ECommExclusive )