Low level CAN binding

Transcription

1 Low level CAN binding A generic way to handle CAN signals AGL F2F Avr/2017 Romain Forlot Linux Embedded Engineer romain.forlot@iot.bzh

2 Clear Isolation CAN agent base on AGL framework Low level CAN operation only depends on equipment High level business logic dedicated to applications Security Built In Navigation APP may access GeoLocation but not Telephony Implement statistic/counter to monitor unexpected behavior Leverage AGL-CC framework API transparency for client applications Reuse existing technology (faster, cheaper, safer) AGL-3+ Low level CAN binding 2

3 AGL CAN Mapping UI Binder Publish Subscribe CAN High Level Binding(s) Logic Aggregation («vehicle.doors.any.open») Advanced Ops Signals - «vehicle.doors.left.open» (Binder Events) CAN Low Level Binding(s) Decoding / Encoding Authentication / Crypto / Firewalling Transaction (set ack...) Stats & Maths Caching (low freq. Signals, get() call) Debug CAN frames CAN BUS AGL-3+ Low level CAN binding 3

4 API Transparency Security Context UI Cynara Security Check Binder CAN API Transport Layer Security Context Binder CAN High Level Binding(s) XXXXX API CAN Low Level Binding(s) AGL-3+ Low level CAN binding 4

5 Low Level Binding Low Level Binding Binary encoding decoding Generate Application Friendly Signal Name & Values Close to Automatic Code Generation OpenXC CAN vector definition in JSON Other CAN vector as CANoe Include Basic Filtering & Statistic GT/GE LT/LE Timer, Cycle, Timestamps Counter: last value, average, invalid ID, Can be ship to developer as binary only AGL-3+ Low level CAN binding 5

6 From OpenXC to AGL CAN Binding OPENXC OPENXC Signal OPENXC Description Signal Description Signal (JSON) Description (JSON) (JSON) Low Level Binding Static Code (AGL) Optional Message Handlers (vendor) AGL Code Generator CAN Decoding/ Encoding C Code (vendor) C/C++ Compiler CAN Low Level Binding (Shared Library) AGL-3+ Low level CAN binding 6

7 Current Binding Capabilities Asynchronous signalization Basic Subscribe/Unsubscribe event model Transport onto WebSocket/DBus AGL-CC event signaling API Notes: handle = afb_daemon_make_event (bindif, name) afb_req_subscribe(request, handle) afb_req_unsubscribe(request, handle) afb_event_push(handle, json_object_get(object)); bindif provided by binder at binding registration time request provided by framework on behalf of client AGL-3+ Low level CAN binding 7

8 API Binding Registration AGL-3+ Low level CAN binding 8

9 Event Subscription [Subscribe/Unsubscribe] [No more signals to process] Waiting verb call [No name provided] [Name provided] Take all signals Find corresponding signals name Make subscription or unsubscription For each signal Create event handler [Regular CAN message] Create Diagnostic handle [Diagnostic message] Add recurring request to the diagnostic manager AGL-3+ Low level CAN binding 9

10 Messages OpenXC Specification bus - name of initialized CAN buses where this message can be found name - The name of the CAN message handler Function name applied to entire raw CAN message max_frequency slow down high level signal frequency (ex: 1/10) signals - A list of CAN signal objects that are in this message Signals generic_name - The name of the associated generic signal name bit_position - Staring bit position of this signal within the message bit_size - The width in bits of the signal factor - The signal value is multiplied by this if set offset - This is added to the signal value if set decoder - type & function name applied to signal bitfield to decode it encoder - Idem to encode a value in bitfield to send over CAN bus states - Mapping between descriptive states and values from CAN max_frequency slow down high level signal frequency (ex: 1/10) send_same if false only send signal when value change ignore, enabled - Control parameters about activation level for a signal writable signal is writable on CAN AGL-3+ Low level CAN binding 10

11 OpenXC Sample Definition "0x620": { "bus": "can0", name : doors, "signals": { "doors.driver.open": { "generic_name": "doors.driver.open", "bit_position": 78, "bit_size": 1, "factor": 0, "offset": 0, "decoder": "decoder_t::booleandecoder"}, "doors.passenger.open": { "generic_name": "doors.passenger.open", "bit_position": 79, "bit_size": 1, "factor": 0, "offset": 0, "decoder": "decoder_t::booleandecoder"}, [...] AGL-3+ Low level CAN binding 11

12 High Level Binding Business API level move > 300m or Angle > 30 or 600s Composing event All doors closes Long Term APIs W3C? Separation/Isolation Responsibility Live cycle Hardware dependencies Long Term API W3C (VISS) VW (ViWi) Others? AGL-3+ Low level CAN binding 12

13 Plan for 2017 ALS Japan (June) Low level filtering Basic statistics Debugging capability Beta for W3C or VIWI API CES (hopefully before Xmas break) Code cleanup & bug fixes Demos: OBD2, tracking cloud demo, trace&debug AGL-3+ Low level CAN binding 13

14 Some References Further Information OpenXC ViWi AGL Download links AppFramework code CAN Low level binding CAN config generator AGL Signaling Benchmark Signaling-Benchmark.pdf AGL-3+ Low level CAN binding 14