Question

I am currently trying to capture serial data within a python script. I intend to begin capturing a log of all the data captured on a serial port while the rest of the script continues to interact with the system I am testing.

If I use pyserial I believe it will end up blocking the rest of the tests I want to carry out until I finish logging.

My options I have considered are:

• Writing another script to capture logs using pyserial, call this script using subprocess.Popen()
• Using built in unix tools such as tail or cat and calling these with subprocess.Popen()

I am sure I could find a way to get either of these to work, but if anyone knows of a more direct way of doing it then I would love to know.

Thank you in advance.

Answer 1

Why create another process for reading data from pySerial ?
For non-blocking the read you can configure the timeout in serial class.
e.g.

ser = serial.Serial()
ser.baudrate = 19200
ser.port = 0
ser.timeout = 2 #By default, this is set to None
ser.open()

Also look at the wrapper class for reference.

http://pyserial.sourceforge.net/examples.html#wrapper-class

You can run a thread to keep reading the data from serial and update it to the buffer.

Creating another process invloves the overhead of IPC and not recommended for this task.