由于工作上的需要，經(jīng)常要與USBCAN打交道，但廠家一般不會(huì)提供PYTHON的例子，于是自己摸索地寫一個(gè)例子出來，以便在工作上隨時(shí)可以使用PYTHON來測(cè)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(gè)ControlCAN.dll，也提供了一個(gè).h文件，如下：
#ifndef CONTROLCAN_H
#define CONTROLCAN_H
////文件版本：v2.00 20150920
//#include
//使用CVI平臺(tái)開發(fā)，請(qǐng)使用該語(yǔ)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(diào)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(yuǎn)程幀
unsigned char ExternFlag;//是否是擴(kuò)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(kuò)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(bǔ)充函數(shù)及數(shù)據(jù)結(jié)構(gòu)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(kuò)展更多的設(shè)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(diào)用這些函數(shù)才可以完成工作，下面就來創(chuàng)建一個(gè)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(diào)用 VCI_OpenDevice出錯(cuò)\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(diào)用 VCI_InitCAN出錯(cuò)\r\n')
ret = canDLL.VCI_StartCAN(VCI_USBCAN2A, 0, 0)
if ret != STATUS_OK:
print('調(diào)用 VCI_StartCAN出錯(cuò)\r\n')
#初始1通道
ret = canDLL.VCI_InitCAN(VCI_USBCAN2A, 0, 1, byref(vci_initconfig))
if ret != STATUS_OK:
print('調(diào)用 VCI_InitCAN 1 出錯(cuò)\r\n')
ret = canDLL.VCI_StartCAN(VCI_USBCAN2A, 0, 1)
if ret != STATUS_OK:
print('調(diào)用 VCI_StartCAN 1 出錯(cuò)\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(diào)用 VCI_Transmit 出錯(cuò)\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(diào)用 VCI_Receive 出錯(cuò)\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(guān)閉
canDLL.VCI_CloseDevice(VCI_USBCAN2A, 0)
運(yùn)行結(jié)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(dá)到這個(gè)程序的目的。
以上這篇使用python來調(diào)用CAN通訊的DLL實(shí)現(xiàn)方法就是小編分享給大家的全部?jī)?nèi)容了，希望能給大家一個(gè)參考，也希望大家多多支持腳本之家。
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