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使用python來調用CAN通訊的DLL實現(xiàn)方法

發(fā)布時間：2020-10-15 04:41:45 來源：腳本之家 閱讀：470 作者：caimouse 欄目：開發(fā)技術

由于工作上的需要，經(jīng)常要與USBCAN打交道，但廠家一般不會提供PYTHON的例子，于是自己摸索地寫一個例子出來，以便在工作上隨時可以使用PYTHON來測試CAN的功能。這里的例子是使用珠海創(chuàng)芯科技有限公司的USBCAN接口卡，他們提供一個ControlCAN.dll，也提供了一個.h文件，如下：

#ifndef CONTROLCAN_H
#define CONTROLCAN_H
 
////文件版本：v2.00 20150920
//#include <cvidef.h>	//使用CVI平臺開發(fā)，請使用該語句。
 
//接口卡類型定義
 
#define VCI_USBCAN1		3
#define VCI_USBCAN2		4
#define VCI_USBCAN2A		4
 
#define VCI_USBCAN_E_U 		20
#define VCI_USBCAN_2E_U 	21
 
 
 
//函數(shù)調用返回狀態(tài)值
#define	STATUS_OK					1
#define STATUS_ERR					0
	
/*------------------------------------------------兼容ZLG的函數(shù)及數(shù)據(jù)類型------------------------------------------------*/
//1.ZLGCAN系列接口卡信息的數(shù)據(jù)類型。
typedef struct _VCI_BOARD_INFO{
		unsigned short	hw_Version;
		unsigned short	fw_Version;
		unsigned short	dr_Version;
		unsigned short	in_Version;
		unsigned short	irq_Num;
		unsigned char	can_Num;
		char	str_Serial_Num[20];
		char	str_hw_Type[40];
		unsigned short	Reserved[4];
} VCI_BOARD_INFO,*PVCI_BOARD_INFO; 
 
//2.定義CAN信息幀的數(shù)據(jù)類型。
typedef struct _VCI_CAN_OBJ{
	unsigned int	ID;
	unsigned int	TimeStamp;
	unsigned char	TimeFlag;
	unsigned char	SendType;
	unsigned char	RemoteFlag;//是否是遠程幀
	unsigned char	ExternFlag;//是否是擴展幀
	unsigned char	DataLen;
	unsigned char	Data[8];
	unsigned char	Reserved[3];
}VCI_CAN_OBJ,*PVCI_CAN_OBJ;
 
//3.定義初始化CAN的數(shù)據(jù)類型
typedef struct _VCI_INIT_CONFIG{
	unsigned long	AccCode;
	unsigned long	AccMask;
	unsigned long	Reserved;
	unsigned char	Filter;
	unsigned char	Timing0;	
	unsigned char	Timing1;	
	unsigned char	Mode;
}VCI_INIT_CONFIG,*PVCI_INIT_CONFIG;
 
///////// new add struct for filter /////////
typedef struct _VCI_FILTER_RECORD{
	unsigned long	ExtFrame;	//是否為擴展幀
	unsigned long	Start;
	unsigned long	End;
}VCI_FILTER_RECORD,*PVCI_FILTER_RECORD;
 
#define EXTERNC		extern "C"
 
EXTERNC unsigned long __stdcall VCI_OpenDevice(unsigned long DeviceType,unsigned long DeviceInd,unsigned long Reserved);
EXTERNC unsigned long __stdcall VCI_CloseDevice(unsigned long DeviceType,unsigned long DeviceInd);
EXTERNC unsigned long __stdcall VCI_InitCAN(unsigned long DeviceType, unsigned long DeviceInd, unsigned long CANInd, PVCI_INIT_CONFIG pInitConfig);
 
EXTERNC unsigned long __stdcall VCI_ReadBoardInfo(unsigned long DeviceType,unsigned long DeviceInd,PVCI_BOARD_INFO pInfo);
 
EXTERNC unsigned long __stdcall VCI_SetReference(unsigned long DeviceType,unsigned long DeviceInd,unsigned long CANInd,unsigned long RefType,void* pData);
 
EXTERNC unsigned long __stdcall VCI_GetReceiveNum(unsigned long DeviceType,unsigned long DeviceInd,unsigned long CANInd);
EXTERNC unsigned long __stdcall VCI_ClearBuffer(unsigned long DeviceType,unsigned long DeviceInd,unsigned long CANInd);
 
EXTERNC unsigned long __stdcall VCI_StartCAN(unsigned long DeviceType,unsigned long DeviceInd,unsigned long CANInd);
EXTERNC unsigned long __stdcall VCI_ResetCAN(unsigned long DeviceType,unsigned long DeviceInd,unsigned long CANInd);
 
EXTERNC unsigned long __stdcall VCI_Transmit(unsigned long DeviceType,unsigned long DeviceInd,unsigned long CANInd,PVCI_CAN_OBJ pSend,unsigned long Len);
EXTERNC unsigned long __stdcall VCI_Receive(unsigned long DeviceType,unsigned long DeviceInd,unsigned long CANInd,PVCI_CAN_OBJ pReceive,unsigned long Len,int WaitTime);
 
 
/*------------------------------------------------其他補充函數(shù)及數(shù)據(jù)結構描述------------------------------------------------*/
 
//USB-CAN總線適配器板卡信息的數(shù)據(jù)類型1，該類型為VCI_FindUsbDevice函數(shù)的返回參數(shù)。
typedef struct _VCI_BOARD_INFO1{
	unsigned long	hw_Version;
	unsigned long	fw_Version;
	unsigned long	dr_Version;
	unsigned long	in_Version;
	unsigned long	irq_Num;
	unsigned char	can_Num;
	unsigned char	Reserved;
	char	str_Serial_Num[8];
	char	str_hw_Type[16];
	char	str_Usb_Serial[4][4];
} VCI_BOARD_INFO1,*PVCI_BOARD_INFO1;
 
//USB-CAN總線適配器板卡信息的數(shù)據(jù)類型2，該類型為VCI_FindUsbDevice函數(shù)的返回參數(shù)。為擴展更多的設備
typedef struct _VCI_BOARD_INFO2{
	unsigned long	hw_Version;
	unsigned long	fw_Version;
	unsigned long	dr_Version;
	unsigned long	in_Version;
	unsigned long	irq_Num;
	unsigned char	can_Num;
	unsigned char	Reserved;
	char	str_Serial_Num[8];
	char	str_hw_Type[16];
	char	str_Usb_Serial[10][4];
} VCI_BOARD_INFO2,*PVCI_BOARD_INFO2;
 
 
#define EXTERNC		extern "C"
 
EXTERNC unsigned long __stdcall VCI_GetReference2(unsigned long DevType,unsigned long DevIndex,unsigned long CANIndex,unsigned long Reserved,unsigned char *pData);
EXTERNC unsigned long __stdcall VCI_SetReference2(unsigned long DevType,unsigned long DevIndex,unsigned long CANIndex,unsigned long RefType,unsigned char *pData);
 
 
EXTERNC unsigned long __stdcall VCI_ConnectDevice(unsigned long DevType,unsigned long DevIndex);
EXTERNC unsigned long __stdcall VCI_UsbDeviceReset(unsigned long DevType,unsigned long DevIndex,unsigned long Reserved);
EXTERNC unsigned long __stdcall VCI_FindUsbDevice(PVCI_BOARD_INFO1 pInfo);
EXTERNC unsigned long __stdcall VCI_FindUsbDevice2(PVCI_BOARD_INFO2 pInfo);
 
 
 
#endif

要調用這些函數(shù)才可以完成工作，下面就來創(chuàng)建一個例子，從CAN的通道0向通道1來發(fā)送一幀CAN數(shù)據(jù)，例子代碼如下：

#python3.6 32位
#https://blog.csdn.net/caimouse/article/details/51749579
#開發(fā)人員：蔡軍生（QQ：9073204） 深圳 2018-3-25
#
from ctypes import *
 
VCI_USBCAN2A = 4
STATUS_OK = 1
class VCI_INIT_CONFIG(Structure): 
  _fields_ = [("AccCode", c_ulong),
        ("AccMask", c_ulong),
        ("Reserved", c_ulong),
        ("Filter", c_ubyte),
        ("Timing0", c_ubyte),
        ("Timing1", c_ubyte),
        ("Mode", c_ubyte)
        ] 
class VCI_CAN_OBJ(Structure): 
  _fields_ = [("ID", c_uint),
        ("TimeStamp", c_uint),
        ("TimeFlag", c_ubyte),
        ("SendType", c_ubyte),
        ("RemoteFlag", c_ubyte),
        ("ExternFlag", c_ubyte),
        ("DataLen", c_ubyte),
        ("Data", c_ubyte*8),
        ("Reserved", c_ubyte*3)
        ] 
 
CanDLLName = 'ControlCAN.dll' #DLL是32位的，必須使用32位的PYTHON
canDLL = windll.LoadLibrary(CanDLLName)
print(CanDLLName)
 
ret = canDLL.VCI_OpenDevice(VCI_USBCAN2A, 0, 0)
print(ret)
if ret != STATUS_OK:
  print('調用 VCI_OpenDevice出錯\r\n')
 
#初始0通道
vci_initconfig = VCI_INIT_CONFIG(0x80000008, 0xFFFFFFFF, 0,
                 2, 0x00, 0x1C, 0)
ret = canDLL.VCI_InitCAN(VCI_USBCAN2A, 0, 0, byref(vci_initconfig))
if ret != STATUS_OK:
  print('調用 VCI_InitCAN出錯\r\n')
 
ret = canDLL.VCI_StartCAN(VCI_USBCAN2A, 0, 0)
if ret != STATUS_OK:
  print('調用 VCI_StartCAN出錯\r\n')
 
#初始1通道
ret = canDLL.VCI_InitCAN(VCI_USBCAN2A, 0, 1, byref(vci_initconfig))
if ret != STATUS_OK:
  print('調用 VCI_InitCAN 1 出錯\r\n')
 
ret = canDLL.VCI_StartCAN(VCI_USBCAN2A, 0, 1)
if ret != STATUS_OK:
  print('調用 VCI_StartCAN 1 出錯\r\n')
 
#通道0發(fā)送數(shù)據(jù)
ubyte_array = c_ubyte*8
a = ubyte_array(1,2,3,4, 5, 6, 7, 64)
ubyte_3array = c_ubyte*3
b = ubyte_3array(0, 0 , 0)
vci_can_obj = VCI_CAN_OBJ(0x0, 0, 0, 1, 0, 0, 8, a, b)
 
ret = canDLL.VCI_Transmit(VCI_USBCAN2A, 0, 0, byref(vci_can_obj), 1)
if ret != STATUS_OK:
  print('調用 VCI_Transmit 出錯\r\n')
 
#通道1接收數(shù)據(jù)
a = ubyte_array(0, 0, 0, 0, 0, 0, 0, 0)
vci_can_obj = VCI_CAN_OBJ(0x0, 0, 0, 1, 0, 0, 8, a, b)
ret = canDLL.VCI_Receive(VCI_USBCAN2A, 0, 1, byref(vci_can_obj), 1, 0)
print(ret)
while ret <= 0:
  print('調用 VCI_Receive 出錯\r\n')
  ret = canDLL.VCI_Receive(VCI_USBCAN2A, 0, 1, byref(vci_can_obj), 1, 0)
if ret > 0:
  print(vci_can_obj.DataLen)
  print(list(vci_can_obj.Data))
 
#關閉
canDLL.VCI_CloseDevice(VCI_USBCAN2A, 0)

運行結果輸出如下：

ControlCAN.dll
1
1
8

[1, 2, 3, 4, 5, 6, 7, 64]

可以看到從通道1里收通道0發(fā)過來的數(shù)據(jù)，達到這個程序的目的。

以上這篇使用python來調用CAN通訊的DLL實現(xiàn)方法就是小編分享給大家的全部內容了，希望能給大家一個參考，也希望大家多多支持億速云。

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