blfpy

A tool for better automating CAN-data proccessing in python

Cross-platform: both windows & linux

• read communication protocol in dbc-format
• read data from blf and mdf(only version 3.00 is tested)
• convert data to structured data
• save structured data as matlab(mat) format

additonal

• convert blf to mdf for fun
• convert mdf to blf for sharing data to colleagues who are not familiar with mdf viewer

setup

• You will have a distributed version with its name like: blfpy-x.x.x-cp37-cp37m-win_amd64.whl (this one is for python 3.7)
• Make the folder where whl file resides in the current folder
• Both in pip or conda environment, type:

pip install blfpy-x.x.x-cp37-cp37m-win_amd64.whl

• blfpy has these third party dependencies: numpy, scipy
• blfpy for following python version is provided: 3.7, 3.8

usage

Although you can use blfpy in pip environment, it is strongly recommended, that you use it in conda environment.

blf as original

• import (better import numpy simultanously as well)

>>> import numpy as np
>>> from blfpy.blfload import blfload

• create blfload object with arguments (dbc, blf)

>>> bl = blfload(dbc='PTCAN_CMatrix_V1.7_PT_VBU.dbc',
                 blf='20200608_IC321_500_009.blf')

• or create blf object without arguments, and fill them afterwards

>>> bl = blfload()
>>> bl.dbc = 'PTCAN_CMatrix_V1.7_PT_VBU.dbc'
>>> bl.blf = '20200608_IC321_500_009.blf'

• without signal selection, all the message in dbc will be parsed and returned
• signals can be selected as follows in form of dict: (signal selection can make parsing phase much faster)

>>> bl.signals = {'VBU_BMS_0x100': ['VBU_BMS_PackU',
                                    'VBU_BMS_PackI',
                                    'VBU_BMS_State'],
                  'VBU_BMS_0x102': ['VBU_BMS_RealSOC',
                                    'VBU_BMS_PackDispSoc'],
                  'VBU_BMS_0x513': ['VBU_BMS_MaxTemp',
                                    'VBU_BMS_MinTemp']}

• call blfload.read method will invoke following functionalities:
  • READ infos from dbc
  • EXTRACT raw data from blf
  • DETERMINE which data will be parsed (default: all) and their indices in raw data
  • DETECT channel: automatically make channel mapping from dbc-infos to data (will also be a user interface later)
  • PARSE data and create a dict in python workspace

Without return value, parsed data will be stored in bl.parsed_data. Otherwise, use can=bl.read() to get bl.parsed_datay

>>> bl.read()
or
>>> can = bl.read()

• for pack voltage in example, use it as follows

>>> time_0x100 = can['VBU_BMS_0x100']['ctime']
>>> packU      = can['VBU_BMS_0x100']['VBU_BMS_PackU']

• sava_data to mat-file or mdf-file
• if filename is omitted, the saved file will have the save basename of the original file

>>> bl.save_data(filename='None'/'xxx', file_format='mat'/'mdf')

mdf as original

• similar to blf, the procedure is as follows
• in order to convert loaded mdf to blf, a communication protocol(dbc-file) must be specified

>>> import numpy as np
>>> from blfpy.mdfload import mdfread
>>> mdf_file = r'../test/2020-07-17_19_IC321_HEV150_SW2.2.4_C2.2.1_FCH_NoreqI_01.dat'
>>> m = mdfread(mdf=mdf_file)
>>> m.read()
>>> m.save_data(file_format='mat')
>>> m.save_data(file_format='blf',
                dbc='../test/dbc/IC321_PTCAN_CMatrix_V1.7_PT装车_VBU.dbc')

what's more

for reading raw 8-bytes data the procedure is as follows

• read normal message only

>>> from blfpy.blfc import read_data
>>> raw = read_data('PTCAN出现少量错误帧.blf'.encode('GBK'))
# raw is a list with 4 elements
# [uint8*8 data,
#  uint32 canid,
#  uint16 channel,
#  float64 time]

• read normal message and errors

>>> from blfpy.blfc import read_data_and_error
>>> raw_and_err = read_data_and_error('PTCAN出现少量错误帧.blf'.encode('GBK'))
# raw_and_err is a list with 5 elements
# [uint8*8 data,
#  uint32 canid,
#  uint16 channel,
#  float64 time,
#  uint8 errorflag {1:errorframe,0:normal}]

TODO

• to support canfd/canfd error frame for reading/parsing blf
• to support multiple channel for reading/parsing blf
• to support multiple channel for converting mdf to blf