Python Serial examples for host and microController

_notes_python_serial.txt

This GitHub Gist can be reached by this short URL: https://tinyurl.com/gs-py-serial

Set-up Python virtual environment
- See https://pythonbasics.org/virtualenv
- Avoids changing operating system installed version of Python environment

Install Python serial module
$ pip install pyserial

Run Thonny IDE and use the Python virtual environment for your host system
- Menu -> Run --> Select interpreter...
  - Alternative Python 3 interpreter or virtual environment
  - Python executable: $HOME/venv/$VENV_NAME/bin/python
- Load "host_serial.py"
- Menu -> Run --> Run current script

-------------------------------------
To Do
~~~~~
- Convert notes to MarkDown ?
  - See https://gist.github.com/ww9/44f08d44327a40d2ab309a349bebec57
- Create proper respository for Python Next workshop / tutorial / examples

host_serial.py

#!/usr/bin/env python3
#
# https://stackoverflow.com/questions/676172/full-examples-of-using-pyserial-package
# https://www.varesano.net/serial-rs232-connections-in-python

import time
import serial

# SERIAL_PORTNAME = "/dev/ttyUSB0"           # Linux example
SERIAL_PORTNAME = "/dev/tty.usbserial-1440"  # Mac OS X example
# SERIAL_PORTNAME = "COM1"                   # Windows example

serial_port = serial.Serial(port=SERIAL_PORTNAME, baudrate=115200)
print(f"Serial port open: {serial_port.isOpen()}")

def read(serial_port):
    buffer = ""
    while True:
        time.sleep(0.1)
        count = serial_port.inWaiting()
        if count:
            buffer += serial_port.read(count).decode("utf-8")
        else:
            break
    return buffer

def write(serial_port, buffer):
    count = serial_port.write(buffer.encode("utf-8"))
    return count

def request(serial_port, command):
    write_count = write(serial_port, command)
    response = read(serial_port)
    end = len(response)
    if response.endswith(">>> "):
        end -= 5
    return response[write_count+1:end]

try:
    while True:
        command = f"{input('> ')}\r"
        response = request(serial_port, command)
        print(response)
except KeyboardInterrupt:
    serial_port.close()
    raise SystemExit("KeyboardInterrupt: abort !")
except EOFError:
    serial_port.close()