amos-ss17-proj4

Raspberry Pi as a simulated car

This project aims to provide a UDS mocking system based on a Raspberry Pi (+ CAN shield) driven by Lua scrips.

Requirements

Tool / Library	Version
Lua	>= 5.2
C++ compiler	>= ISO C++14
can-isotp	>= git 2017/04/22
can-utils (optional)	>= git 2015/09/02
CppUnit (optional)	>= 1.10
Doxygen (optional)	>= 1.8
graphviz (optional)	>= 2.38

For instructions to set up all necessary installations, read the HACKME.

Using the Lua scripts

Basics Communication

To simulate a ECU (Electronic Control Unit), the Lua file hold various tables describing the data and behavior. Therefore a single ECU has to provide at least a RequesId and a ResponseId to be able to communicate via the CAN ISO-TP protocol. Note: A single Lua file could contain various ECUs.

PCM = { -- ECU name
    RequestId = 0x100,
    ResponseId = 0x200,
    BroadcastId = 0x300, -- Optional, 0x7DF on default
}

Providing the Simulation Data

To provide a set of response data, there are two possibilities. The first option is to do this via a ReadDataByIdentifier-table, which holds a set of receiving requests and the corresponding answers. The response answer could be a string or a numerical type. The second option is to provide a Raw-table which does basically the same, with the slightly difference, that the entire data is provided as a literal hexadecimal string. This makes it possible to harness data sets from previous scans or logs. However, white-spaces in-between the string bytes are ignored to allow a easier way to separate the data sections.

PCM = {
    RequestId = 0x100,
    ResponseId = 0x200,

    ReadDataByIdentifier = {
        ["F1 90"] = "SALGA2EV9HA298784",
        ["F1 24"] = "HPLA-12345-AB",
        ["1E 23"] = "231132",
    },

    Raw = {
        ["10 02"] = "50 02 00 19 01 F4",
        ["22 FA BC"] = "10 33 11",
    }
}

Integrated Functions

Since it could be a little inconvenient to provide the entire data set in a static, Look-Up-Table styled way, there are also functions to allow a more advanced behavior.

The following functions are available:

ascii(string) – Converts a UTF-8 string into a lexical hexadecimal byte string
toByteResponse(number, number) – Converts a int number into a hexadecimal byte string
getCurrentSession() – Returns the current session
switchToSession(number) – Sets ECU in the given session
sleep(number) – Sleeps the amount in milliseconds before proceeding any further
sendRaw(string) – Sends the given raw-string immediately

All these functions could be used in self defined functions to build a more advanced behavior structure.

Example:

...
    Raw = {
        ["22 F1 91"] = "62 F1 91" .. ascii("SALGA2EV9HA298784"),
        ["19 02 B1"] = function (request)
            myNumber = 21550
            return "59 02 FF E3" .. toByteResponse(myNumber, 3) -- "59 02 FF E3 00 54 2E" 
        end,

        ["19 02 B2"] = function (request)
            session = getCurrentSession()
            return "47 11" .. toByteResponse(session, 1) -- "47 11 01"
        end,

        ["19 02 B3"] = function (request)
            switchToSession(3) -- extended session
            session = getCurrentSession()
            return "47 11" .. toByteResponse(session, 1) -- "47 11 03"
        end,

        ["19 02 AF"] = function (request)
            sendRaw("7F 19 78")           -- send this data section
            sleep(5000)                   -- wait 5 seconds
            return "59 02 FF E3 00 54 2F" -- send the rest
        end
    },
...

trommler / car-simulator