Serial

It is very common to connect to a microprocessor using a serial port. This is often the method used to upload programmes.

This makes it easy to use as a simple logging channel. Below is a simple Python example code that will connect to a COM port that has a microprocessor connected

Note that this is a blocking implementation, while reading from the serial port the code will remain in an infinite loop An try catch loop is used to catch the ctrl+c used to end this programme. Replace <COMPORT> with the name of the COM port you wish to connect to

import sys

import datetime as dt
import json
import argparse as arg

import serial

def readserial(comport: str, baudrate: int, timestamp=False):
    """Function to read value from a serial port
    Assumes it is a json formatted string

    Parameters
    ----------
    comport : str
        the com port to connect to
    baudrate : int
        the baud rate of the connection
    timestamp : bool, optional
        Whether to add timestamp to data, by default False
    """
    ser = serial.Serial(
        comport, baudrate, timeout=0.1
    )  # 1/timeout is the frequency at which the port is read

    try:
        while True:

            data = ser.readline().decode().strip()

            if "{" in data:
                data = json.loads(data)
                if timestamp:
                    ct = dt.datetime.now()
                    data = {"timestamp": int(ct.timestamp()), **data}
                print(data)
                # This can be saved to file or database depending on need
            elif data:
                print(data)

    except KeyboardInterrupt:
        print("Ending Logging")
        sys.exit()


if __name__ == "__main__":
    out = get_formatted_datetime()
    print(f"Readying Logging at:{out}")

    port = <COMPORT>
    baud = 115200   #default for Pico
    timestamp = True

    print(f"Connecting to {port}, with Baud rate {baud}")
    if timestamp:
        print("Time stamps will be added")

    readserial(port, baud, timestamp)