如何添加新的CAN卡¶
简介¶
控制器区域网络（CAN）是在许多微控制器和设备中密集使用的网络，用于在没有主计算机帮助的情况下在设备之间传输数据。
Apollo中使用的默认CAN卡是 ESD CAN-PCIe卡。您可以使用以下步骤添加新的CAN卡：
添加新CAN卡¶
添加新的CAN卡需要完成以下几个步骤:
实现新CAN卡的
CanClient类。在
CanClientFactory中注册新的CAN卡。更新配置文件。
以下步骤展示了如何添加新的CAN卡 - 示例添加CAN卡到您的工程。
步骤 1¶
实现新CAN卡的CanClient类
下面的代码展示了如何实现 CANClient 类:
#include <string>
#include <vector>
#include "hermes_can/include/bcan.h"
#include "modules/canbus/can_client/can_client.h"
#include "modules/canbus/common/canbus_consts.h"
#include "modules/common/proto/error_code.pb.h"
/**
* @namespace apollo::canbus::can
* @brief apollo::canbus::can
*/
namespace apollo {
namespace canbus {
namespace can {
/**
* @class ExampleCanClient
* @brief The class which defines a Example CAN client which inherits CanClient.
*/
class ExampleCanClient : public CanClient {
public:
/**
* @brief Initialize the Example CAN client by specified CAN card parameters.
* @param parameter CAN card parameters to initialize the CAN client.
* @return If the initialization is successful.
*/
bool Init(const CANCardParameter& parameter) override;
/**
* @brief Destructor
*/
virtual ~ExampleCanClient() = default;
/**
* @brief Start the Example CAN client.
* @return The status of the start action which is defined by
* apollo::common::ErrorCode.
*/
apollo::common::ErrorCode Start() override;
/**
* @brief Stop the Example CAN client.
*/
void Stop() override;
/**
* @brief Send messages
* @param frames The messages to send.
* @param frame_num The amount of messages to send.
* @return The status of the sending action which is defined by
* apollo::common::ErrorCode.
*/
apollo::common::ErrorCode Send(const std::vector<CanFrame>& frames,
int32_t* const frame_num) override;
/**
* @brief Receive messages
* @param frames The messages to receive.
* @param frame_num The amount of messages to receive.
* @return The status of the receiving action which is defined by
* apollo::common::ErrorCode.
*/
apollo::common::ErrorCode Receive(std::vector<CanFrame>* const frames,
int32_t* const frame_num) override;
/**
* @brief Get the error string.
* @param status The status to get the error string.
*/
std::string GetErrorString(const int32_t status) override;
private:
...
...
};
} // namespace can
} // namespace canbus
} // namespace apollo
步骤 2¶
在CanClientFactory中注册新CAN卡，
在 CanClientFactory中添加如下代码:
void CanClientFactory::RegisterCanClients() {
Register(CANCardParameter::ESD_CAN,
[]() -> CanClient* { return new can::EsdCanClient(); });
// register the new CAN card here.
Register(CANCardParameter::EXAMPLE_CAN,
[]() -> CanClient* { return new can::ExampleCanClient(); });
}
步骤 3¶
接下来，需要更新配置文件
在/modules/canbus/proto/can_card_parameter.proto添加 EXAMPLE_CAN
message CANCardParameter {
enum CANCardBrand {
FAKE_CAN = 0;
ESD_CAN = 1;
EXAMPLE_CAN = 2; // add new CAN card here.
}
... ...
}
Update /modules/canbus/conf/canbus_conf.pb.txt
... ...
can_card_parameter {
brand:EXAMPLE_CAN
type: PCI_CARD // suppose the new can card is PCI_CARD
channel_id: CHANNEL_ID_ZERO // suppose the new can card has CHANNEL_ID_ZERO
}
... ...