Overview

This SDK was used for the eco-system partners which provided the video surveillance terminal of commercial vehicle. It is not suitable for the general-purpose of vehicle data acquisition

1. Provided a standard and extensive definition for data structure of data acquisition, especially for commercial vehicle, such as GPS, Speed, Voltage and so forth;
2. Designed a well-packaged communication framework between the hardware drivers and user application in this SDK. Several callback interface was pre-defined, the developers of hardware drivers only need to customerize these callback functions according to different hardware functions. All data-exchange and validation are packaged efficiently and securely;
3. Plain C language programming friendly and compatible for all Linux environment and various CPU archs. following google c/c++ style

---

Architecture

Entities: Rule Engine App, Vehicle Property Acq App, Vehicle Proerpty Acq SDK Callback Interface(needed to be implement by User):

• vehicle_prop_get_cb;
• vehicle_prop_set_cb;
• vehicle_prop_release_memory;

---

Data Structure

Vehicle Property Definition

/**
 * Encapsulates the property name and the associated value. It
 * is used across various API calls to set values, get values or
 * to notify values changed.
 */
typedef struct vehicle_property {
  /** Property identifier */
  int prop_id;

  /** Time is elapsed nanoseconds since boot */
  long timestamp;

  /** The length of the property body */
  size_t length;

  /** The property body */
  char body[0];
} vehicle_property_t;

Data Mapping Relation

---

Inteface

Callback Definition

typedef int (*vehicle_property_set_callback)(const vehicle_property_t *data);
typedef int (*vehicle_property_get_callback)(vehicle_property_t *data);
typedef void (*vehicle_release_memory_from_get_callback)(vehicle_property_t *data);

typedef struct vehicle_callbacks {
  /** set to sizeof(vehicle_callbacks_t) */
  size_t size;
  vehicle_property_get_callback vehicle_get_cb;
  vehicle_property_set_callback vehicle_set_cb;
  vehicle_release_memory_from_get_callback vehicle_release_memory_from_get_cb;
} vehicle_callbacks_t;

/**
 * Init the vehicle client.
 */
int vehicle_init(vehicle_callbacks_t callbacks);

/**
 * Releases resources that created in vehicle_init().
 */
int vehicle_release();

/**
 * Suggests that an vehicle property has changed.
 *
 * data is OWNED by the caller, who is responsible for releasing
 * the memory after the method returns.
 */
int vehicle_prop_changed(int property_id, const void *property_data_struct, size_t property_data_struct_length);

---

File Struct

Totally, there are ten files, detailed descriptions was shown as below.

File Name	Description
htt_client_internal.c	a internal http client implement.
htt_client_internal.h
http_server_internal.c	a internal http server implement.
http_server_internal.h
msgpack_util.c	msg pack utility
msgpack_util.h
vehicle_property_acq.c	inteface definition and export
vehicle_proerpty_acq.h
driver_app_demo.c	example
safety_engine_demo.c	example

---

Compiling Procedure

Compiling Tool

cmake	3.5.1+
gcc	5.4.0+

Dependency Library

libcurl	7.77.0
libmicrohttpd	0.9.72
msgpack	3.3.0

Compiling Procedure

#compile the dependency library by Makefile in third-party
make -C third-party -f Makefile prepare

#compile project and example of CMakeList.txt
cmake . && make

the operation of cross-platfrom compiling could be executed by ./build-cross-compile.sh

---

Licensing

MIT