Table of Contents. Abstract 1.1. Document revisions Architecture 1.4. Installation. Usage 1.5

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2 Table of Contents Abstract Document revisions Architecture Installation Usage

3 Abstract This project proposes a Low Level CAN Binding for AGL, with the following features: CAN messages and diagnostic messages (OBD-II) are currently supported Description of CAN messages is done using JSON definition following OpenXC specifications (project OpenXC/vi-firmware) Encoding/Decoding of CAN messages reuses OpenXC libraries Proposes an API to other AGL applications and services to read/write on CAN bus(es). Uses a publish/subscribe model with filtering for sending messages to clients for efficiency

4 Document revisions Date Version Designation Author 20 Mar Initial release R. Forlot [ Iot.bzh ] S. Douheret [ Iot.bzh ] 4

5 AGL CAN binding architecture proposal It's meant to generate from a JSON file describing CAN messages and diagnostic message (OBD2 for now), a cpp file to integrate with the project. Once generated binding is built with it and result will be a widget file to install on an AGL target system. Bringing CAN management into the AGL project is more than allowing decode and print CAN messages, lot of tools can do that (Wireshark, CAN-utils,...). The goal is to provide a common API and abstraction to the CAN bus then you can bring some more high level functionalities to the system. CAN binding will be separated in two parts: 5

6 High level: Binding from which others applications will connect to. It will provides valuable access to the CAN bus by aggregate signals or providing new signals from several originals. For example, a signal exposing whether or not a door is open, no matter which one it is. Also, we can imagine an application which supervise if there is no one in the car but moving (1m, 2m?) to alert the owner of an unexpected behavior. The high level binding will sends a single event representing that behavior to the application which in turn will send a phone message to. Low level: Decode messages that transit and send event through Application Framework to the subscribers with human readable message. It provides some basic access to the bus + some basic mathematical, statistical features (last_values, min, max, timestamps, averaging) as well as basic filter to get discerning signal only (This part are not implemented yet in the low level). 6

7 Last be not least, the low level binding can be shipped as binary only using OpenXC inspired AGL low level CAN binding Generator. 7

8 Prerequisites An AGL system installed with latest Chinook version (>3.0.2). Make sure you built the AGL generator else you will not be able to generate custom low-level CAN binding. Generator can be found here with the attached instruction to install and run it. It will produce a configuration-generated.cpp file to paste in the source, src/, directory. Make sure you already set up the AGL SDK using the following SDK Quick Setup Guide. Alternatively, please refer to official guides available on AGL Developer Site. To get the correct SDK version installed, you must prepare your environment with the chinook-next version. To do so, run the following command in your docker image in the step 4 in place of... [ prepare build environment ]... : NOTE These commands assume that proprietary graphic drivers for Renesas Porter board are located in /home/devel/share/proprietary-renesas-rcar directory. $ prepare_meta -f chinook-next -o /xdt -l /home/devel/mirror -p /home/devel/share/proprietary-renesas-rcar/ -t porter -e wipeconfig -e rm_work $ /xdt/build/agl-init-build-env An USB CAN adapter connected to connector through the right cable). Getting started Use of CAN config generator Build requirements CMake version 3.0 or later G++, Clang++ or any C++11 compliant compiler. Boost filesystem program_options system You can install any of these using your package manager. For instance, inside the iotbzh's docker image, you must enter this command : $ sudo apt-get update $ sudo apt-get install libboost-system-dev libboost-filesystem-dev libboost-program-options-dev You may want to install libboost-all-dev to get all boost components even if it's not required. Compile CAUTION It is very important that you do not source the SDK environment file to compile this project because some build requirements aren't installed in the AGL SDK for now. $ export PATH=$PATH:/xdt/sdk/sysroots/x86_64-aglsdk-linux/usr/bin $ export WD=$(pwd) 8

9 $ git clone $ cd can-config-generator $ mkdir -p build $ cd build $ cmake -G "Unix Makefiles".. $ make Naming convention We chose a doted naming convention because it's a well know schema. It separates and organize names into hierarchy. From the left to right, you describe your names using the more common ancestor at the left then more you go to the right the more it will be accurate. Let's take an example, here is an example about standard PID name following this convention: engine.load engine.coolant.temperature fuel.pressure intake.manifold.pressure engine.speed vehicle.speed intake.air.temperature mass.airflow throttle.position running.time EGR.error fuel.level barometric.pressure commanded.throttle.position ethanol.fuel.percentage accelerator.pedal.position hybrid.battery-pack.remaining.life engine.oil.temperature engine.torque NOTE It's recommended that you follow this naming convention to named your CAN signals. There is only character * that is forbidden in names because it's used as wildcard for subscription and unsubscription. This described in the below chapter. Write your custom decoder The function declaration of a custom decoder must match: openxc_dynamicfield custom_decoder(can_signal_t& signal, const std::vector<can_signal_t>& signals, float value, bool* send); Where signal is a reference to the can signal this is handling, signals is a reference to a vector of all signals, value the raw float value from CAN message and send a flag indicate if it is ok to send the event. More information can be found in Doxygen documentation from source repository. Available default decoder You can use some basic decoders provided by default in the binding which are: decoder_t::noopdecoder : Default decoder if not specified, return raw value from signal's bitfield. decoder_t::booleandecoder : Coerces a numerical value to a boolean. decoder_t::statedecoder : Find and return the corresponding string state for a CAN signal's raw integer 9

10 value. Generating JSON from Vector CANoe Database CAUTION This chapter has not been tested since we haven't necessary automotive tools for that. If you use CANoe to store your gold standard CAN signal definitions, you may be able to use the OpenXC xml_to_json.py script to make your JSON for you. First, export the Canoe.dbc file as XML - you can do this with Vector CANdb++. Next, create a JSON file according to the format defined above, but only define: CAN messages. Name of CAN signals within messages and their generic_name. Optionnaly name of diagnostic messages and their name. To install the OpenXC utilities and runs xml_to_json.py script: $ sudo pip install openxc $ cd /usr/local/lib/python2.7/dist-packages/openxc/generator Assuming the data exported from Vector is in signals.xml and your minimal mapping file is mapping.json, run the script: $ python -m openxc.utils./xml_to_json.py signals.xml mapping.json signals.json The script scans mapping.json to identify the CAN messages and signals that you want to use from the XML file. It pulls the neccessary details of the messages (bit position, bit size, offset, etc) and outputs the resulting subset as JSON into the output file, signals.json. The resulting file together with mapping.json will work as input to the code generation script. Generate your config file To generate your config file you just have to run the generator using the -m option to specify your JSON file. $./can-config-generator -m../tests/basic.json -o configuration-generated.cpp If you omit the -o option, then code is generated on the stdout. You also can specify a header and a footer file. These files must be valid C++ fragment as long as they will be inserted as is. Use the -h option to display help. CAUTION: Each diagnostic_message must define the same bus as the binding will use only one bus. Supported OpenXC items About now, compliance with OpenXC reference is in progress, can-config-generator and CAN_signaling will implement them soon. initializers, loopers, commands and handlers nodes are ignored for now. This generator will follow OpenXC support status of the low level CAN signaling binding. NOTE: The buses item will not be supported by this generator because the binding use another way to declare and configure buses. Please refer to the binding's documentation. Compile and install the binding 10

11 Clone the binding repository, copy the generated file and updated the git submodules. Execute the following commands from this repository: $ cd $WD $ git clone -b v1.0 $ cd CAN_signaling $ git submodule init $ git submodule update $ cp $WD/can-config-generator/build/configuration-generated.cpp src/ Installation using make install With an AGL SDK environment correctly configured and sourced, I suggest you to set the TARGET variable in the CMakeLists.txt file located under src directory if you have an AGL target already running in your network. Then you can directly build and install the binding and source directory on your target system. Execute these commands to get your binding compile: $ mkdir -p build $ cd build $ cmake.. $ make And if you have set TARGET variable, you can install it on your AGL system: $ make install [ 16%] Built target bitfield [ 27%] Built target isotp [ 40%] Built target openxc [ 48%] Built target uds [ 97%] Built target low-can-binding [100%] Built target widget Install the project Install configuration: "" true { "added": "low-can-binding@0.1" } It's possible that you'll see the following message : Error org.freedesktop.dbus.error.failed: "system error" It's because installation remove the binding before installing it. If it is the first time that you make the installation then you'll have this message in place of true. Manual Installation To install it manually, you need to copy the low-can-binding.wgt file on your target, then from it execute the following commands : On your host, to copy over the network : $ scp low-can-binding.wgt root@<target_ip>:~ On the target, assuming wgt file is in the root home directory: # afm-util install low-can-binding.wgt 11

12 { "added": } 12

13 Install AFB Websocket CLI client to test the binding. You can test it using afb-client-demo CLI tool provided by the RPM package libafbwsc-dev. You can find this package in your build environment, using docker SDK recommended setup the file is /xdt/build/tmp/deploy/rpm/<your-target-arch>/. After a successful bitbake build and using Renesas RCar Gen2, Porter, you have to copy the file if your board is connected to your network and you know its IP address: $ scp /xdt/build/tmp/deploy/rpm/cortex15hf_neon/libafbwsc-dev-1.0-r0.cortexa15hf_neon.rpm root@<target_ip>:~ Else, you have to copy into the SDcard with the AGL image installed on it. From the docker image copy RPM to the shared directory between docker image and your host: $ cp /xdt/build/tmp/deploy/rpm/cortex15hf_neon/libafbwsc-dev-1.0-r0.cortexa15hf_neon.rpm ~/share Then plugin you SDcard in your Linux host (Windows can't read ext4 filesystem AGL runs on) and copy RPM file on it. From your host, identify SDcard block device node here it is sdc with the correct capacity automounted by the desktop manager: $ lsblk loop1 7:1 0 2G 0 loop docker-253: pool 253: G 0 dm docker-253: e9f80849a2681e18549d3a4238cbf031e44052e36cd88a0abf041804b799b61c 253:4 0 10G 0 dm /var/lib/docker/devicemapper/mnt/e9f80849a2681e18549d3a4238cbf031e44052e36cd88a0abf b799b61c sdb 8: G 0 disk sdb2 8: G 0 part Shamash-agl 253: G 0 lvm /ho me/claneys/workspace/agl-docker sdb1 8: M 0 part /bo ot sr0 11: M 0 rom loop0 7: G 0 loop docker-253: pool 253: G 0 dm docker-253: e9f80849a2681e18549d3a4238cbf031e44052e36cd88a0abf041804b799b61c 253:4 0 10G 0 dm /var/lib/docker/devicemapper/mnt/e9f80849a2681e18549d3a4238cbf031e44052e36cd88a0abf b799b61c sdc 8: G 0 disk sdc1 8:33 1 2G 0 part /ru n/media/claneys/97f418a5-612f-44e9-b968-a sda 8: G 0 disk sda2 8: G 0 part Shamash-home 253: G 0 lvm /ho me Shamash-root 253:0 0 50G 0 lvm / sda1 8:1 0 16G 0 part [SW AP] Copy, still from your host: CAUTION: Make sure to sync IO with sync command before unplug your SDcard. It could be corrupted if removed before all pending IO aren't done. $ sudo umount /dev/sdc1 13

14 $ export SDCARD=/mnt $ sudo mount /dev/sdc1 $SDCARD $ sudo cp ~/devel/docker/share/libafbwsc-dev-1.0-r0.cortexa15hf_neon.rpm $SDCARD/home/root $ sync $ sudo umount $SDCARD Insert the modified SDcard in your Porter board and boot from it. You are ready to go. Configure the AGL system Virtual CAN device Connected to the target, here is how to load the virtual CAN device driver and set up a new vcan device : # modprobe vcan # ip link add vcan0 type vcan # ip link set vcan0 up CAN device using the USB CAN adapter Using real connection to CAN bus of your car using the USB CAN adapter connected to the OBD2 connector. Once connected, launch dmesg command and search which device to use : # dmesg [...] [ ] usb 1-3: new full-speed USB device number 4 using ohci-pci [ ] can: controller area network core (rev abi 9) [ ] NET: Registered protocol family 29 [ ] usb 1-3: USB disconnect, device number 4 [ ] usb 1-2: USB disconnect, device number 3 [ ] usb 1-2: new full-speed USB device number 5 using ohci-pci [ ] usb 1-2: USB disconnect, device number 5 [ ] CAN device driver interface [ ] usb 1-2: new full-speed USB device number 6 using ohci-pci [ ] usb_8dev 1-2:1.0 can0: firmware: 1.7, hardware: 1.0 [ ] usbcore: registered new interface driver usb_8dev Here device is named can0. This instruction assuming a speed of kbps for your CAN bus, you can try others supported bitrate like , if doesn't work: # ip link set can0 type can bitrate # ip link set can0 up # ip link show can0 can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN qlen 10 link/can can state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 0 bitrate sample-point tq 125 prop-seg 6 phase-seg1 7 phase-seg2 2 sjw 1 sja1000: tseg tseg sjw 1..4 brp brp-inc 1 clock For a Porter board, you'll have your CAN device as can1 because can0 device. already exists as an embedded The instructions will be the same: # ip link set can1 type can bitrate # ip link set can1 up 14

15 # ip link show can1 can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN qlen 10 link/can can state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 0 bitrate sample-point tq 125 prop-seg 6 phase-seg1 7 phase-seg2 2 sjw 1 sja1000: tseg tseg sjw 1..4 brp brp-inc 1 clock Configure the binding Configure the binding specifying in the JSON configuration file the CAN device(s) that it will to connect to. Edit file /var/lib/afm/applications/low-can-binding/0.1/can_buses.json and change the CAN device name to the one you will use : Using virtual CAN device as described in the previous chapter: { } "canbus": "vcan0" Using real CAN device, this example assume CAN bus traffic will be on can0. { } "canbus": "can0" On a Porter board there is an embedded CAN device so can0 already exists. So you might want to use your USB CAN adapter plugged to the OBD2 connector, in this case use can1 : { } "canbus": "can1" If you have several specify CAN bus devices use an array: { } "canbus": [ "can0", "can1" ] CAUTION VERY IMPORTANT: Make sure the CAN bus(es) you specify in your configuration file match those specified in your generated source file with the can-config-generator. Run it, test it, use it! You can run the binding using afm-util tool, here is the classic way to go : # afm-util run low-can-binding@0.1 1 You can find instructions to use afm-util tool here, as well as documentation about Application Framework. But you can't control nor interact with it because you don't know security token that Application Framework gaves it at launch. 15

16 So, to test it, it is better to launch the binding manually. In the following example, we will use port 1234 and left empty security token for testing purpose: # afb-daemon --ldpaths=/usr/lib/afb:/var/lib/afm/applications/low-can-binding/0.1/libs/ --rootdir=/var/lib/afm/applic ations/low-can-binding/0.1/ --port= token= NOTICE: binding [/usr/lib/afb/afb-dbus-binding.so] calling registering function afbbindingv1register NOTICE: binding /usr/lib/afb/afb-dbus-binding.so loaded with API prefix dbus NOTICE: binding [/usr/lib/afb/authlogin.so] calling registering function afbbindingv1register NOTICE: binding /usr/lib/afb/authlogin.so loaded with API prefix auth NOTICE: binding [/var/lib/afm/applications/low-can-binding/0.1/libs//low-can-binding.so] calling registering function afbbindingv1register NOTICE: binding /var/lib/afm/applications/low-can-binding/0.1/libs//low-can-binding.so loaded with API prefix low-can NOTICE: Waiting port=1234 rootdir=/var/lib/afm/applications/low-can-binding/0.1/ NOTICE: Browser URL= NOTICE: vcan0 device opened and reading {binding low-can} NOTICE: Initialized 1/1 can bus device(s) {binding low-can} On another terminal, connect to the binding using previously installed AFB Websocket CLI tool: # afb-client-demo ws://localhost:1234/api?token= You will be on an interactive session where you can communicate directly with the binding API. The binding provides at this moment 2 verbs, subscribe and unsubscribe, which can take argument by a JSON event object. The argument value is the CAN message generic_name as described in the JSON file used to generate cpp file for the binding. To use the AFB Websocket CLI tool, a command line will be like the following : <api> <verb> <arguments> Where: API : low-can. Verb : subscribe or unsubscribe Arguments : { "event": "driver.doors.open" } Subscription and unsubscription You can ask to subscribe to chosen CAN event with a call to subscribe API verb with the CAN messages name as JSON argument. NOTE: If no argument is provided, then you'll subscribe to all signals at once. For example from a websocket session: low-can subscribe { "event": "doors.driver.open" } ON-REPLY 1:low-can/subscribe: {"jtype":"afb-reply","request":{"status":"success","uuid":"a18fd375-b6fa-4c0e-a1d4-9d ae8"}} Subscription and unsubscription can take wildcard in their event value. To receive all doors events : low-can subscribe { "event" : "doors*" } ON-REPLY 1:low-can/subscribe: {"jtype":"afb-reply","request":{"status":"success","uuid":"511c872e-d7f3-4f3b-89c2-aa9a 3e9fbbdb"}} 16

17 Then you will receive an event each time a CAN message is decoded for the event named doors.driver.open ON-EVENT low-can/messages.doors.driver.open({"event":"low-can\/messages.doors.driver.open","data":{"name":"messages.d oors.driver.open","value":true},"jtype":"afb-event"}) Notice that event shows you that the CAN event is named messages.doors.driver.open but you ask for event about doors.driver.open. This is because all CAN messages or diagnostic messages are prefixed by the JSON parent node name, messages for CAN messages and diagnostic_messages for diagnostic messages like OBD2. This will let you subscribe or unsubcribe to all signals at once, not recommended, and better make filter on subscribe operation based upon their type. Examples: low-can subscribe { "event" : "*speed*" } --> will subscribe to all messages with speed in their name. Search will be make without prefix for it. low-can subscribe { "event" : "speed*" } --> will subscribe to all messages begin by speed in their name. Search will be make without prefix for it. low-can subscribe { "event" : "messages*speed*" } --> will subscribe to all CAN messages with speed in their name. Se arch will be on prefixed messages here. low-can subscribe { "event" : "messages*speed" } --> will subscribe to all CAN messages ending with speed in their na me. Search will be on prefixed messages here. low-can subscribe { "event" : "diagnostic*speed*" } --> will subscribe to all diagnostic messages with speed in their name. Search will be on prefixed messages here. low-can subscribe { "event" : "diagnostic*speed" } --> will subscribe to all diagnostic messages ending with speed in their name. Search will be on prefixed messages here. You can stop receiving event from it by unsubscribe the signal the same way you did for subscribe low-can unsubscribe { "event": "doors.driver.open" } ON-REPLY 2:low-can/unsubscribe: {"jtype":"afb-reply","request":{"status":"success"}} low-can unsubscribe { "event" : "doors*" } ON-REPLY 3:low-can/unsubscribe: {"jtype":"afb-reply","request":{"status":"success"}} Using CAN utils to monitor CAN activity You can watch CAN traffic and send custom CAN messages using can-utils preinstalled on AGL target. To watch watch going on a CAN bus use: # candump can0 Or for an USB CAN adapter connected to porter board: # candump can1 Send a custom message: # cansend can0 ID#DDDDAAAATTTTAAAA You can also replay a previously dumped CAN logfiles. These logfiles can be found in can_samples directory under Git repository. Following examples use a real trip from an Auris Toyota car. Trace has been recorded from a CAN device can0 so you have to map it to the correct one you use for your tests. Replay on a virtual CAN device vcan0 : # canplayer -I trip_test_with_obd2_vehicle_speed_requests vcan0=can0 17

18 Replay on a CAN device can0 : # canplayer -I trip_test_with_obd2_vehicle_speed_requests can0 Replay on a CAN device can1 (porter by example): # canplayer -I trip_test_with_obd2_vehicle_speed_requests can1=can0 18