全部学习汇总： GreyZhang/python_basic: My learning notes about python. (github.com)
使用dbc文件建模完成CAN通讯是一种比较高效的开发模式，不过在建模的过程中dbc文件中描述的数据需要自己去定义。使用文本编辑工具打开dbc文件可以看到，实际上dbc文件是一个可以进行语义解析的文本。这样，通过脚本语言便可以轻松的实现simulink建模所需要的数据定义。
以下面的dbc文件为例，简单做一下尝试。首先定义dbc文件中定义两个消息帧，以及消息帧相关的部分变量。出于示例的简单，只定义了8位和16位的数据。具体的dbc文件文本如下：
VERSION ""
NS_ :
NS_DESC_
CM_
BA_DEF_
BA_
VAL_
CAT_DEF_
CAT_
FILTER
BA_DEF_DEF_
EV_DATA_
ENVVAR_DATA_
SGTYPE_
SGTYPE_VAL_
BA_DEF_SGTYPE_
BA_SGTYPE_
SIG_TYPE_REF_
VAL_TABLE_
SIG_GROUP_
SIG_VALTYPE_
SIGTYPE_VALTYPE_
BO_TX_BU_
BA_DEF_REL_
BA_REL_
BA_DEF_DEF_REL_
BU_SG_REL_
BU_EV_REL_
BU_BO_REL_
SG_MUL_VAL_
BS_:
BU_:
BO_ 2147486754 Message2: 8 Vector__XXX
BO_ 2147486753 Message1: 8 Vector__XXX
SG_ message_var3_16bit : 55|16@0+ (1,0) [0|0] "" Vector__XXX
SG_ message_var2_16bit : 39|16@0+ (1,0) [0|0] "" Vector__XXX
SG_ message_var2_8bit : 31|8@0+ (1,0) [0|0] "" Vector__XXX
SG_ message_var1_16bit : 15|16@0+ (1,0) [0|0] "" Vector__XXX
SG_ test_flag : 7|8@0+ (1,0) [0|0] "" Vector__XXX
BA_DEF_ SG_ "SigType" ENUM "Default","Range","RangeSigned","ASCII","Discrete","Control","ReferencePGN","DTC","StringDelimiter","StringLength","StringLengthControl";
BA_DEF_ SG_ "GenSigEVName" STRING ;
BA_DEF_ SG_ "GenSigILSupport" ENUM "No","Yes";
BA_DEF_ SG_ "GenSigSendType" ENUM "Cyclic","OnWrite","OnWriteWithRepetition","OnChange","OnChangeWithRepetition","IfActive","IfActiveWithRepetition","NoSigSendType";
BA_DEF_ BO_ "GenMsgFastOnStart" INT 0 100000;
BA_DEF_ SG_ "GenSigInactiveValue" INT 0 0;
BA_DEF_ BO_ "GenMsgCycleTimeFast" INT 0 3600000;
BA_DEF_ BO_ "GenMsgNrOfRepetition" INT 0 1000000;
BA_DEF_ SG_ "GenSigStartValue" INT 0 10000;
BA_DEF_ BO_ "GenMsgDelayTime" INT 0 1000;
BA_DEF_ BO_ "GenMsgILSupport" ENUM "No","Yes";
BA_DEF_ BO_ "GenMsgStartDelayTime" INT 0 100000;
BA_DEF_ BU_ "NodeLayerModules" STRING ;
BA_DEF_ BU_ "ECU" STRING ;
BA_DEF_ BU_ "NmJ1939SystemInstance" INT 0 15;
BA_DEF_ BU_ "NmJ1939System" INT 0 127;
BA_DEF_ BU_ "NmJ1939ManufacturerCode" INT 0 2047;
BA_DEF_ BU_ "NmJ1939IndustryGroup" INT 0 7;
BA_DEF_ BU_ "NmJ1939IdentityNumber" INT 0 2097151;
BA_DEF_ BU_ "NmJ1939FunctionInstance" INT 0 7;
BA_DEF_ BU_ "NmJ1939Function" INT 0 255;
BA_DEF_ BU_ "NmJ1939ECUInstance" INT 0 3;
BA_DEF_ BU_ "NmJ1939AAC" INT 0 1;
BA_DEF_ BU_ "NmStationAddress" INT 0 255;
BA_DEF_ BO_ "GenMsgSendType" ENUM "cyclic","NotUsed","IfActive","NotUsed","NotUsed","NotUsed","NotUsed","NotUsed","noMsgSendType";
BA_DEF_ BO_ "GenMsgRequestable" INT 0 1;
BA_DEF_ BO_ "GenMsgCycleTime" INT 0 3600000;
BA_DEF_ SG_ "SPN" INT 0 524287;
BA_DEF_ "DBName" STRING ;
BA_DEF_ "BusType" STRING ;
BA_DEF_ "ProtocolType" STRING ;
BA_DEF_ BO_ "VFrameFormat" ENUM "StandardCAN","ExtendedCAN","reserved","J1939PG";
BA_DEF_DEF_ "SigType" "Default";
BA_DEF_DEF_ "GenSigEVName" "Env@Nodename_@Signame";
BA_DEF_DEF_ "GenSigILSupport" "Yes";
BA_DEF_DEF_ "GenSigSendType" "NoSigSendType";
BA_DEF_DEF_ "GenMsgFastOnStart" 0;
BA_DEF_DEF_ "GenSigInactiveValue" 0;
BA_DEF_DEF_ "GenMsgCycleTimeFast" 0;
BA_DEF_DEF_ "GenMsgNrOfRepetition" 0;
BA_DEF_DEF_ "GenSigStartValue" 0;
BA_DEF_DEF_ "GenMsgDelayTime" 0;
BA_DEF_DEF_ "GenMsgILSupport" "Yes";
BA_DEF_DEF_ "GenMsgStartDelayTime" 0;
BA_DEF_DEF_ "NodeLayerModules" "";
BA_DEF_DEF_ "ECU" "";
BA_DEF_DEF_ "NmJ1939SystemInstance" 0;
BA_DEF_DEF_ "NmJ1939System" 0;
BA_DEF_DEF_ "NmJ1939ManufacturerCode" 0;
BA_DEF_DEF_ "NmJ1939IndustryGroup" 0;
BA_DEF_DEF_ "NmJ1939IdentityNumber" 0;
BA_DEF_DEF_ "NmJ1939FunctionInstance" 0;
BA_DEF_DEF_ "NmJ1939Function" 0;
BA_DEF_DEF_ "NmJ1939ECUInstance" 0;
BA_DEF_DEF_ "NmJ1939AAC" 0;
BA_DEF_DEF_ "NmStationAddress" 254;
BA_DEF_DEF_ "GenMsgSendType" "noMsgSendType";
BA_DEF_DEF_ "GenMsgRequestable" 1;
BA_DEF_DEF_ "GenMsgCycleTime" 0;
BA_DEF_DEF_ "SPN" 0;
BA_DEF_DEF_ "DBName" "";
BA_DEF_DEF_ "BusType" "CAN";
BA_DEF_DEF_ "ProtocolType" "J1939";
BA_DEF_DEF_ "VFrameFormat" "J1939PG";
BA_ "DBName" "ECUTstInf";
BA_ "VFrameFormat" BO_ 2147486754 3;
BA_ "VFrameFormat" BO_ 2147486753 3;
编写Python脚本，首先数据的解析。完成一个M脚本，脚本会通过对MATLAB Workspace中的数据模板进行拷贝修改完成数据定义。
脚本如下（其中Excel写入变量信息表的功能可以去掉）：
#!/usr/bin/python
################################################################################
# Grey 2016.03.02
# Update : add the function to gnerate M script for data import.
# Grey 2016.03.01
# generate variables list according to dbc file.
# Inupt : dbc file name as a string, excel file name as a string.
# Output : An excel file : variables list file
#
import re
from xlwt import Workbook
def GetVarList(dbc_file,var_list,model_name):
data_c_file = model_name + '_Data.c'
data_head_file = model_name + '_Data.h'
fid = open('var_import.m','w')
book = Workbook()
sheet_result = book.add_sheet('variables')
data_type_dict = {2:'uint8',8:'uint8',12:'uint16',16:'uint16'}
text_lines = open(dbc_file,'r')
regexp_var = re.compile(r'SG_\s+(\w+)\s+.*\|(\w+)@')
var_detail = re.compile(r'SG_.*\((\S+),(\S+)\).*\[(\S+)\|(\S+)\].*\"(\S*)\"')
index_col_num = 0
var_name_col_num = 1
data_type_col_num = 2
raw_num = 0
sheet_result.write(raw_num,index_col_num,'index')
sheet_result.write(raw_num,var_name_col_num,'variable name')
sheet_result.write(raw_num,data_type_col_num,'data type')
for each_line in text_lines:
line_info = each_line.strip()
if line_info.startswith('SG_ '):
search_result = regexp_var.search(line_info)
var_detail_result = var_detail.search(line_info)
try:
raw_num += 1
var_name = search_result.group(1)
data_index = int(search_result.group(2))
data_type = data_type_dict[data_index]
factor_value = var_detail_result.group(1)
bias_value = var_detail_result.group(2)
min_value = var_detail_result.group(3)
max_value = var_detail_result.group(4)
unit_str = var_detail_result.group(5)
sheet_result.write(raw_num,index_col_num,raw_num)
sheet_result.write(raw_num,var_name_col_num,var_name)
sheet_result.write(raw_num,data_type_col_num,data_type)
if data_type == 'uint8':
fid.write("%s = copy(base_8bit);\n" % var_name)
fid.write("%s.DataType = \'fixdt(0,8,%s,%s)\';\n" %(var_name,factor_value,bias_value))
fid.write("%s.Min = %s;\n" % (var_name,0))
fid.write("%s.Max = %s;\n" % (var_name,255))
fid.write("%s.DocUnits = \'%s\';\n" % (var_name,unit_str))
fid.write("%s.RTWInfo.CustomAttributes.DefinitionFile = '%s';\n" % (var_name,data_c_file))
fid.write("%s.RTWInfo.CustomAttributes.HeaderFile = '%s';\n" % (var_name,data_head_file))
elif data_type == 'uint16':
fid.write("%s = copy(base_16bit);\n" % var_name)
fid.write("%s.DataType = \'fixdt(0,16,%s,%s)\';\n" %(var_name,factor_value,bias_value))
fid.write("%s.Min = %s;\n" % (var_name,0))
fid.write("%s.Max = %s;\n" % (var_name,65535))
fid.write("%s.DocUnits = \'%s\';\n" % (var_name,unit_str))
fid.write("%s.RTWInfo.CustomAttributes.DefinitionFile = '%s';\n" % (var_name,data_c_file))
fid.write("%s.RTWInfo.CustomAttributes.HeaderFile = '%s';\n" % (var_name,data_head_file))
#print("%s factor : %s\t bias : %s\tMin : %s\tMax : %s\tUnit : %s" % \
#(var_name,factor_value,bias_value,min_value,max_value,unit_str))
except:
print("ERROR:%s" % line_info)
book.save(var_list)
fid.close()
print("Process Done! Please refer to excel file %s" % var_list)
GetVarList('test.dbc','temp.xls','DbcTst')
运行脚本，生成如下内容的M文件：
message_var3_16bit = copy(base_16bit);
message_var3_16bit.DataType = 'fixdt(0,16,1,0)';
message_var3_16bit.Min = 0;
message_var3_16bit.Max = 65535;
message_var3_16bit.DocUnits = '';
message_var3_16bit.RTWInfo.CustomAttributes.DefinitionFile = 'DbcTst_Data.c';
message_var3_16bit.RTWInfo.CustomAttributes.HeaderFile = 'DbcTst_Data.h';
message_var2_16bit = copy(base_16bit);
message_var2_16bit.DataType = 'fixdt(0,16,1,0)';
message_var2_16bit.Min = 0;
message_var2_16bit.Max = 65535;
message_var2_16bit.DocUnits = '';
message_var2_16bit.RTWInfo.CustomAttributes.DefinitionFile = 'DbcTst_Data.c';
message_var2_16bit.RTWInfo.CustomAttributes.HeaderFile = 'DbcTst_Data.h';
message_var2_8bit = copy(base_8bit);
message_var2_8bit.DataType = 'fixdt(0,8,1,0)';
message_var2_8bit.Min = 0;
message_var2_8bit.Max = 255;
message_var2_8bit.DocUnits = '';
message_var2_8bit.RTWInfo.CustomAttributes.DefinitionFile = 'DbcTst_Data.c';
message_var2_8bit.RTWInfo.CustomAttributes.HeaderFile = 'DbcTst_Data.h';
message_var1_16bit = copy(base_16bit);
message_var1_16bit.DataType = 'fixdt(0,16,1,0)';
message_var1_16bit.Min = 0;
message_var1_16bit.Max = 65535;
message_var1_16bit.DocUnits = '';
message_var1_16bit.RTWInfo.CustomAttributes.DefinitionFile = 'DbcTst_Data.c';
message_var1_16bit.RTWInfo.CustomAttributes.HeaderFile = 'DbcTst_Data.h';
test_flag = copy(base_8bit);
test_flag.DataType = 'fixdt(0,8,1,0)';
test_flag.Min = 0;
test_flag.Max = 255;
test_flag.DocUnits = '';
test_flag.RTWInfo.CustomAttributes.DefinitionFile = 'DbcTst_Data.c';
test_flag.RTWInfo.CustomAttributes.HeaderFile = 'DbcTst_Data.h';
在MATLAB的Workspace中定义8位以及16位的数据定义模板，然后执行M文件。
数据定义模板：
运行后，Workspace中已经生成dbc中的数据定义，只需要把这些数据保存成mat文件即可保存使用。
后续，提供使用这个示例中的dbc文件进行建模的方法。
