Python Serial Tools

I recently came across a nice way of dumping serial data into a log file using pyserial.

If it isn’t installed yet:

pip3 install pyserial

Dumping data to a log file

With the teensy attached to my PC, I can connect using:

python3 -m serial.tools.miniterm /dev/tty.usbmodem39153401 \
115200 > log.csv

The output looks like:

--- Miniterm on /dev/tty.usbmodem39153401  115200,8,N,1 ---
--- Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---

--- exit ---

So CTRL + ] will stop the logging.

The generalized command is:

python3 -m serial.tools.miniterm <PORT> <BAUD> > <LOGFILE>

We can also not direct data to the log file if we want to just use the miniterm.

List Ports

Another helpful utility to check what ports we can actually direct serial to is list_ports

python3 -m serial.tools.list_ports -v

Which outputs:

/dev/cu.Bluetooth-Incoming-Port
    desc: n/a
    hwid: n/a
/dev/cu.usbmodem39153401
    desc: USB Serial
    hwid: USB VID:PID=16C0:0483 SER=3915340 LOCATION=20-3
2 ports found

The -v flag can be omitted to just show the port names.