The calibrationReader package reads characteristics, system constants, measurement definitions etc. from an a2l file and correlates it with the data from a corresponding hex oder s19 file. It is build to cover the ASAM MCD 2MC specification in its current version 1.7.1 As of now the package only uses the metadata part of the ASAM MCD 2MC standard. The interface descriptions which are used to communicate with an ECU and are defined in the AML datastructure are not within the scope of this package.
Right now the package can parse a2l-files as well as the corresponding IntelHex32 or Motorola S19 files. And it is quite fast at that. Currently a real world A2L(80MB) with its corresponding Hex File(10MB) will be parsed in less than a second.
The package still lacks the last bit of work which is implementing the methods for axis_pts, axis_descr, record_layout and fnc_values in order to understand the memory layout and position of a specific characteristic. This currently worked on as everything else seems to be quite stable now. Once completely implemented version 1.0 will be released.
This is only a preliminary explanation on how to access the datastructures as the API will be formalized when version 1.0 releases with the full scope of the package implemented.
calibrationData, err := ReadCalibration(a2lFilePath, hexFilePath)
parses an a2l and hex file into datastructures. All relevant information e.g. Record Layouts, Measurements, Characterstics, etc. are part of a module which is in turn part of the Project whithin the a2l data structure. An a2l file can contain several modules but in most real world applications only contains one. So indexOfModuleInProject (see below) can basically assumed to be 0. In the future this will be solved more elegantly with a cd.SetModule method. So the user can define the module he is going to work on.
mod := calibrationData.A2l.Project.Modules[indexOfModuleInProject]
Most datastructures that are directly below a module within the a2l data structure hierarchy are accessible through maps by their identifiers.
To access System Constants:
sc, exists := mod.SystemConstants["NameOfSystemConstant"]
To access Characteristics:
c, exists := mod.Characteristics["NameOfCharacteristic"]
and so on.
To access a specific memory location in the hex-file (contains a single byte):
b, exists := calibrationData.Hex[12345]
Coverage was previously at upper 60s but has temporarily plummeted. 60% includes all of the active paths in hex, s19 and a2l, excluding error handling for every specific error possible. Because I recently started implementing reading characteristic values from hex the coverage keeps falling. This will only be a temporary issue as test files and test cases will be added after implementation. I'll cross verify the values against other knwon and "battle tested" parsers and then implement testcases to check that calibrationReader gets to the same values as the other parser. However this will be done once the intial implementation is finished. It makes no sense to implement test cases just for test coverage's sake until actual values can be read and cross verified.
I am a mechanical engineer, so any code you see might not be up to the standards of true/correct/modern/acceptable software development ;) Feedback is always appreciated.
The only dependency outside the go standard library is currently zerolog. The package is - and will always be - released under MIT license. Feel free to do with it what you want :)