【GD32L233C-START Review】3. Implementation of USB keyboard

bzhou830

【GD32L233C-START Review】3. Implementation of USB keyboard [Copy link]

<i class="pstatus"> This post was last edited by bzhou830 on 2022-2-27 21:59 </i> [ [GD32L233C-START Review] 1. Unboxing test to light up the color screen](https://bbs.eeworld.com.cn/thread-1193742-1-1.html " [GD32L233C-START Review] 1. Unboxing test to light up the color screen") [ [GD32L233C-START Review] 2. Super Mario runs](https://bbs.eeworld.com.cn/thread-1193914-1-1.html " [GD32L233C-START Review] 2. Super Mario runs") ## 1. Implementation ideas There is a USB CDC case in the official routine of the GD32L233C-start board, and there are no other USB-related cases. However, I found a USB keyboard case in GD32L233R_EVAL_Demo_Suites, so the easiest way to implement it is to transplant this demo to the GD32L233C-start board. Since there is only one external key for input besides the reset key on the GD32L233C-start, this key is used to implement keyboard input. It is just equivalent to implementing a keyboard with only one key. ## 2. Device Descriptor The configuration of the device descriptor can be seen in USBlyzer as follows: 
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 ``` usb_desc_dev hid_dev_desc = { .header = { .bLength = USB_DEV_DESC_LEN, .bDescriptorType = USB_DESCTYPE_DEV }, #ifdef LPM_ENABLED .bcdUSB = 0x0201U, #else .bcdUSB = 0x0200U, #endif /* LPM_ENABLED */ .bDeviceClass = 0x00U, .bDeviceSubClass = 0x00U, .bDeviceProtocol = 0x00U, .bMaxPacketSize0 = USBD_EP0_MAX_SIZE, .idVendor = USBD_VID, //0x28E9U .idProduct = USBD_PID, //0x0380U .bcdDevice = 0x0100U, .iManufacturer = STR_IDX_MFC, .iProduct = STR_IDX_PRODUCT, .iSerialNumber = STR_IDX_SERIAL, .bNumberConfigurations = USBD_CFG_MAX_NUM }; ``` ## 3. Configuration description 
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 ``` .config = { .header = { .bLength = sizeof(usb_desc_config), .bDescriptorType = USB_DESCTYPE_CONFIG }, .wTotalLength = USB_HID_CONFIG_DESC_LEN, .bNumInterfaces = 0x01U, .bConfigurationValue = 0x0 1U, .iConfiguration = 0x00U, .bmAttributes = 0xA0U, .bMaxPower = 0x32U }, ``` ## 4. Interface descriptor, endpoint descriptor, HID descriptor [attach]590185 [/attach] ``` //Interface descriptor .header = { .bLength = sizeof(usb_desc_itf), .bDescriptorType = USB_DESCTYPE_ITF }, .bInterfaceNumber = 0x00U, .bAlternateSetting = 0x00U, .bNumEndpoints = 0x01U, .bInterfaceClass = USB_HID_CLASS, .bInterfaceSubClass = USB_HID_SUBCLASS_BOOT_ITF, .bInterfaceProtocol = USB_HID_PROTOCOL_KEYBOARD, .iInterface = 0x00U ``` ``` //HID descriptor.header = { .bLength = sizeof(usb_desc_hid), .bDescriptorType = USB_DESCTYPE_HID }, .bcdHID = 0x0111U, .bCountryCode = 0x00U, .bNumDescriptors = 0x01U, .bDescriptorType = USB_DESCTYPE_REPORT, . wDescriptorLength = USB_HID_REPORT_DESC_LEN, ``` ``` //Endpoint descriptor.header = { .bLength = sizeof(usb_desc_ep), .bDescriptorType = USB_DESCTYPE_EP }, .bEndpointAddress = HID_IN_EP, .bmAttributes = USB_EP_ATTR_INT,.wMaxPacketSize   = HID_IN_PACKET,
  .bInterval    = 0x40U
```

## 5. HID报表描述符

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```
const uint8_t hid_report_desc[USB_HID_REPORT_DESC_LEN] = {
  0x05, 0x01,/* USAGE_PAGE (Generic Desktop) */
  0x09, 0x06,/* USAGE (Keyboard) */
  0xa1, 0x01,/* COLLECTION (Application) */

0x05, 0x07,/* USAGE_PAGE (Keyboard/Keypad) */
  0x19, 0xe0,/* USAGE_MINIMUM (Keyboard LeftControl) */
  0x29, 0xe7,/* USAGE_MAXIMUM (Keyboard Right GUI) */
  0x15, 0x00,/* LOGICAL_MINIMUM (0) */
  0x25, 0x01,/* LOGICAL_MAXIMUM (1) */
  0x95, 0x08,/* REPORT_COUNT (8) */
  0x75, 0x01,/* REPORT_SIZE (1) */
  0x81, 0x02,/* INPUT (Data,Var,Abs) */

0x95, 0x01,/* REPORT_COUNT (1) */
  0x75, 0x08,/* REPORT_SIZE (8) */
  0x81, 0x03,/* INPUT (Cnst,Var,Abs) */

0x95, 0x06,/* REPORT_COUNT (6) */
  0x75, 0x08,/* REPORT_SIZE (8) */
  0x15, 0x00,/* LOGICAL_MINIMUM (0) */
  0x26, 0xFF, 0x00,/* LOGICAL_MAXIMUM (255) */
  0x05, 0x07,/* USAGE_PAGE (Keyboard/Keypad) */
  0x19, 0x00,/* USAGE_MINIMUM (Reserved (no event indicated)) */
  0x29, 0x65,/* USAGE_MAXIMUM (Keyboard Application) */
  0x81, 0x00,/* INPUT (Data,Ary,Abs) */

0xc0   /* END_COLLECTION */
};
```

## 6. 按键处理
按键直接用循环扫描的方式进行：
```
static uint8_t key_state(void)
{
  if(SET == gpio_input_bit_get(GPIOA, GPIO_PIN_0)) 
        {
                return CHAR_B;
  }
  return 0U;
}

static void hid_key_data_send(usb_dev *udev)
{
  standard_hid_handler *hid = (standard_hid_handler *)udev->class_data[0];

if(hid->prev_transfer_complete) {
  switch(key_state()) {
  case CHAR_A:
    hid->data[2] = 0x04U;
    break;
  case CHAR_B:
    hid->data[2] = 0x05U;
    break;
  default:
    break;
  }

if(0U != hid->data[2]) {
    hid_report_send(udev, hid->data, HID_IN_PACKET);
  }
  }
}

```
至此，USB键盘就实现好了，运行起来在设备管理器里面可以找到一个VID是0x28E9U， PID是0x0380U的HID设备，按下按键即输入大写字母B。/* LOGICAL_MINIMUM (0) */
  0x26, 0xFF, 0x00,/* LOGICAL_MAXIMUM (255) */
  0x05, 0x07,/* USAGE_PAGE (Keyboard/Keypad) */
  0x19, 0x00,/* USAGE_MINIMUM (Reserved (no event indicated)) */
  0x29, 0x65,/* USAGE_MAXIMUM (Keyboard Application) */
  0x81, 0x00,/* INPUT (Data,Ary,Abs) */

0xc0   /* END_COLLECTION */
};
```

## 6. 按键处理
按键直接用循环扫描的方式进行：
```
static uint8_t key_state(void)
{
  if(SET == gpio_input_bit_get(GPIOA, GPIO_PIN_0)) 
        {
                return CHAR_B;
  }
  return 0U;
}

static void hid_key_data_send(usb_dev *udev)
{
  standard_hid_handler *hid = (standard_hid_handler *)udev->class_data[0];

if(hid->prev_transfer_complete) {
  switch(key_state()) {
  case CHAR_A:
    hid->data[2] = 0x04U;
    break;
  case CHAR_B:
    hid->data[2] = 0x05U;
    break;
  default:
    break;
  }

if(0U != hid->data[2]) {
    hid_report_send(udev, hid->data, HID_IN_PACKET);
  }
  }
}

```
至此，USB键盘就实现好了，运行起来在设备管理器里面可以找到一个VID是0x28E9U， PID是0x0380U的HID设备，按下按键即输入大写字母B。/* LOGICAL_MINIMUM (0) */
  0x26, 0xFF, 0x00,/* LOGICAL_MAXIMUM (255) */
  0x05, 0x07,/* USAGE_PAGE (Keyboard/Keypad) */
  0x19, 0x00,/* USAGE_MINIMUM (Reserved (no event indicated)) */
  0x29, 0x65,/* USAGE_MAXIMUM (Keyboard Application) */
  0x81, 0x00,/* INPUT (Data,Ary,Abs) */

0xc0   /* END_COLLECTION */
};
```

## 6. 按键处理
按键直接用循环扫描的方式进行：
```
static uint8_t key_state(void)
{
  if(SET == gpio_input_bit_get(GPIOA, GPIO_PIN_0)) 
        {
                return CHAR_B;
  }
  return 0U;
}

static void hid_key_data_send(usb_dev *udev)
{
  standard_hid_handler *hid = (standard_hid_handler *)udev->class_data[0];

if(hid->prev_transfer_complete) {
  switch(key_state()) {
  case CHAR_A:
    hid->data[2] = 0x04U;
    break;
  case CHAR_B:
    hid->data[2] = 0x05U;
    break;
  default:
    break;
  }

if(0U != hid->data[2]) {
    hid_report_send(udev, hid->data, HID_IN_PACKET);
  }
  }
}

```
至此，USB键盘就实现好了，运行起来在设备管理器里面可以找到一个VID是0x28E9U， PID是0x0380U的HID设备，按下按键即输入大写字母B。

soso

The layout is very comfortable, praise

bzhou830

soso posted on 2022-2-28 09:34 The layout is very comfortable, like it

Use markdown formatting

serialworld

Can you share the source file?

Thanks!

bzhou830

serialworld posted on 2022-3-13 10:14 Can you share the source file? For reference. Thank you!

The source code is publicly available on github.

https://github.com/bzhou830/GD32/tree/main/GD32L233C_START_Demo_Suites/Projects/08_USBD_keybord

serialworld

Thanks for sharing!!

【GD32L233C-START Review】3. Implementation of USB keyboard [Copy link]

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