Logging / Debugging

Every module of this package uses the Python Logging Facility to log debug messages, warnings etc. This page gives a quick overview how it works.

Usage

To enable the logging facility in your project, just add the following lines to the top of your main Python script:

import logging
logging.basicConfig()

Log Raw Transmitted/Received Data

When debugging issues on a lower layer, it might be useful to see what data (raw bytes) is actually sent to the underlying port, and what data is received from the connected device. This data can be shown by changing the logging level to DEBUG:

from sensirion_shdlc_driver import ShdlcSerialPort, ShdlcConnection, ShdlcDevice

import logging
logging.basicConfig(level=logging.DEBUG)  # <- logging level set here

with ShdlcSerialPort(port='COM1', baudrate=115200) as port:
    device = ShdlcDevice(ShdlcConnection(port), slave_address=0)
    print("Version: {}".format(device.get_version()))

This way the raw data is printed to the console:

DEBUG:sensirion_shdlc_driver.port:Open ShdlcSerialPort on 'COM1' with 115200 bit/s.
DEBUG:sensirion_shdlc_driver.connection:Opened ShdlcConnection on 'COM1@115200'.
DEBUG:sensirion_shdlc_driver.port:ShdlcSerialPort send raw: [0x7E, 0x00, 0xD1, 0x00, 0x2E, 0x7E]
DEBUG:sensirion_shdlc_driver.port:ShdlcSerialPort received raw: [0x7E, 0x00, 0xD1, 0x00, 0x07, 0x05, 0x08, 0x00, 0x03, 0x00, 0x01, 0x00, 0x16, 0x7E]
Version: Firmware 5.8, Hardware 3.0, Protocol 1.0

Change Logging Verbosity of Modules

Since every module contains its own logging object log, it’s even possible to set the logging level of each module independently. For example, the verbosity of the ShdlcPort classes could be reduced by changing their logging level to CRITICAL (i.e. only critical messages will be logged):

import sensirion_shdlc_driver
from sensirion_shdlc_driver import ShdlcSerialPort, ShdlcConnection, ShdlcDevice

import logging
logging.basicConfig(level=logging.DEBUG)

# Make port less verbose
sensirion_shdlc_driver.port.log.setLevel(level=logging.CRITICAL)

with ShdlcSerialPort(port='COM1', baudrate=115200) as port:
    device = ShdlcDevice(ShdlcConnection(port), slave_address=0)
    print("Version: {}".format(device.get_version()))

This way you won’t see the raw transmitted data:

DEBUG:sensirion_shdlc_driver.connection:Opened ShdlcConnection on 'COM1@115200'.
Version: Firmware 5.8, Hardware 3.0, Protocol 1.0