linux usb 通信例子

sudo apt-get update
sudo apt-get install libusb-1.0-0-dev

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

int main() {
    libusb_device **devs;
    libusb_device_handle *dev_handle;
    ssize_t cnt;
    int r;

    // 初始化libusb
    r = libusb_init(NULL);
    if (r < 0) {
        fprintf(stderr, "Init Error %d\n", r);
        return 1;
    }

    // 获取设备列表
    cnt = libusb_get_device_list(NULL, &devs);
    if (cnt < 0) {
        fprintf(stderr, "Get Device Error\n");
        libusb_exit(NULL);
        return 1;
    }

    // 遍历设备列表
    for (ssize_t i = 0; i < cnt; i++) {
        struct libusb_device_descriptor desc;
        r = libusb_get_device_descriptor(devs[i], &desc);
        if (r < 0) {
            fprintf(stderr, "Failed to get device descriptor\n");
            continue;
        }

        printf("Device Descriptor:\n");
        printf("  bLength             %5d\n", desc.bLength);
        printf("  bDescriptorType     %5d\n", desc.bDescriptorType);
        printf("  bcdUSB              %2x.%02x\n", desc.bcdUSB >> 8, desc.bcdUSB & 0xff);
        printf("  bDeviceClass        %5d\n", desc.bDeviceClass);
        printf("  bDeviceSubClass     %5d\n", desc.bDeviceSubClass);
        printf("  bDeviceProtocol     %5d\n", desc.bDeviceProtocol);
        printf("  bMaxPacketSize0     %5d\n", desc.bMaxPacketSize0);
        printf("  idVendor            0x%04x\n", desc.idVendor);
        printf("  idProduct           0x%04x\n", desc.idProduct);
        printf("  bcdDevice           %2x.%02x\n", desc.bcdDevice >> 8, desc.bcdDevice & 0xff);
        printf("  iManufacturer       %5d\n", desc.iManufacturer);
        printf("  iProduct            %5d\n", desc.iProduct);
        printf("  iSerialNumber       %5d\n", desc.iSerialNumber);
        printf("  bNumConfigurations  %5d\n", desc.bNumConfigurations);

        // 打开特定设备（例如，Vendor ID为0x1d6b，Product ID为0x0002）
        if (desc.idVendor == 0x1d6b && desc.idProduct == 0x0002) {
            dev_handle = libusb_open_device_with_vid_pid(NULL, desc.idVendor, desc.idProduct);
            if (dev_handle == NULL) {
                fprintf(stderr, "Could not open USB device\n");
                continue;
            }

            // 进行设备通信（例如，获取设备状态）
            unsigned char data[64];
            int transferred;
            r = libusb_bulk_transfer(dev_handle, LIBUSB_ENDPOINT_IN | 0x81, data, sizeof(data), &transferred, 0);
            if (r == 0 && transferred > 0) {
                printf("Received %d bytes: ", transferred);
                for (int j = 0; j < transferred; j++) {
                    printf("%02x ", data[j]);
                }
                printf("\n");
            } else {
                fprintf(stderr, "Bulk transfer failed: %d\n", r);
            }

            libusb_close(dev_handle);
            break;
        }
    }

    // 释放设备列表
    libusb_free_device_list(devs, 1);

    // 退出libusb
    libusb_exit(NULL);

    return 0;
}

gcc -o usb_example usb_example.c -lusb-1.0
./usb_example