libusb_bulk_transfer 事例

以下是使用libusb库进行bulk传输的示例代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <libusb-1.0/libusb.h>

#define VENDOR_ID       0x1234  // 你的设备的厂商ID
#define PRODUCT_ID      0x5678  // 你的设备的产品ID
#define ENDPOINT_IN     0x81    // 用于IN传输的端点地址
#define ENDPOINT_OUT    0x02    // 用于OUT传输的端点地址
#define MAX_PACKET_SIZE 64      // 最大数据包大小

int main(int argc, char *argv[]) {
    libusb_device **list;
    libusb_device_handle *handle = NULL;
    int result, num_devices, i, transferred;
    unsigned char buffer[256];

    // 初始化libusb库
    result = libusb_init(NULL);
    if (result < 0) {
        printf("libusb initialization failed\n");
        return 1;
    }

    // 获取连接的USB设备列表
    num_devices = libusb_get_device_list(NULL, &list);
    if (num_devices < 0) {
        printf("could not get device list\n");
        libusb_exit(NULL);
        return 1;
    }

    // 查找指定的USB设备
    for (i = 0; i < num_devices; i++) {
        libusb_device *device = list[i];
        struct libusb_device_descriptor desc;

        result = libusb_get_device_descriptor(device, &desc);
        if (result < 0) {
            printf("could not get device descriptor\n");
            continue;
        }

        if (desc.idVendor == VENDOR_ID && desc.idProduct == PRODUCT_ID) {
            // 打开设备
            result = libusb_open(device, &handle);
            if (result < 0) {
                printf("could not open device\n");
                continue;
            }

            // 重置设备
            result = libusb_reset_device(handle);
            if (result < 0) {
                printf("could not reset device\n");
                libusb_close(handle);
                handle = NULL;
                continue;
            }

            // claim interface
            result = libusb_claim_interface(handle, 0);
            if (result < 0) {
                printf("could not claim interface\n");
                libusb_close(handle);
                handle = NULL;
                continue;
            }

            // 向设备写入数据
            memset(buffer, 0, sizeof(buffer));
            buffer[0] = 0x01;
            result = libusb_bulk_transfer(handle, ENDPOINT_OUT, buffer, MAX_PACKET_SIZE, &transferred, 0);
            if (result < 0) {
                printf("could not write data\n");
                libusb_release_interface(handle, 0);
                libusb_close(handle);
                handle = NULL;
                continue;
            }

            // 从设备读取数据
            memset(buffer, 0, sizeof(buffer));
            result = libusb_bulk_transfer(handle, ENDPOINT_IN, buffer, MAX_PACKET_SIZE, &transferred, 0);
            if (result < 0) {
                printf("could not read data\n");
                libusb_release_interface(handle, 0);
                libusb_close(handle);
                handle = NULL;
                continue;
            }

            // 处理读取到的数据
            printf("received %d bytes of data: ", transferred);
            for (i = 0; i < transferred; i++) {
                printf("%02x ", buffer[i]);
            }
            printf("\n");

            // 释放接口
            libusb_release_interface(handle, 0);

            // 关闭设备
            libusb_close(handle);
            handle = NULL;

            break;
        }