Question

我正在努力上传到Digispark board。它使用micronucleus bootloader，我可以看到uploader code。我对它进行了一些修改，看看接口和端点的数量：

    nucleus->device = usb_open(dev);

    // added by me - start
    int interfaces, endpoints, j;
    struct usb_interface_descriptor *interface = NULL;

    interfaces = dev->config->bNumInterfaces;
    fprintf(stderr, "Found interfaces: %i\n", interfaces);

    interface = &(dev->config->interface[0].altsetting[0]);
    fprintf(stderr, "Endpoints: %i\n", interface->bNumEndpoints);
    // added by me - end

    // get nucleus info
    unsigned char buffer[4];
    int res = usb_control_msg(nucleus->device, USB_ENDPOINT_IN| USB_TYPE_VENDOR | USB_RECIP_DEVICE, 0, 0, 0, (char *)buffer, 4, MICRONUCLEUS_USB_TIMEOUT);

我想知道它是如何工作的，因为接口＃0没有端点：

$./micronucleus --type intel-hex /tmp/Start.ino.hex 
> Please plug in the device ... 
> Press CTRL+C to terminate the program.
Found interfaces: 1
Endpoints: 0
> Device is found!
connecting: 40% complete
> Device has firmware version 1.6
> Available space for user applications: 6012 bytes
> Suggested sleep time between sending pages: 8ms
> Whole page count: 94  page size: 64
> Erase function sleep duration: 752ms
parsing: 60% complete
> Erasing the memory ...
erasing: 80% complete
> Starting to upload ...
writing: 100% complete
>> Micronucleus done. Thank you!

通常我希望界面有2个端点（从usb.h开始）：

#define USB_ENDPOINT_IN         0x80
#define USB_ENDPOINT_OUT        0x00

任何人都可以解释一下usb_control_msg(nucleus->device, USB_ENDPOINT_IN| USB_TYPE_VENDOR | USB_RECIP_DEVICE, 0, 0, 0, (char *)buffer, 4, MICRONUCLEUS_USB_TIMEOUT);如何在没有端点的情况下工作吗？

Answer 1

在这里回答：https://arduino.stackexchange.com/a/44026/8327。简而言之：它没有端点（0除外），仅使用控制传输进行交互。

如何与没有接口端点的CDC设备进行交互？

1 个答案: