符合 HID 标准的触摸屏数据包数据结构

Question

我需要找出符合 HID 的触摸屏（单点触控）输入数据结构（如字节顺序以及每个字节应写入的内容）。

我使用了来自 Microsoft 官方 docs 的符合 HID 标准的触摸屏描述符

在使用设备管理器的主机 PC 中，我可以看到它成功枚举了符合 HID 的设备。现在我想向主机发送 HID 报告，但问题是我还没有找到类似用于触摸屏的 HID 启动协议（对于鼠标和键盘，它在 USB org 规范中明确定义）。 这是我用来创建触摸屏 HID 报告的代码示例，它可以工作，但不如预期。我通过研究大量 github 代码和阅读文章找到了这种字节组合，但我想找到一些可以证明排序正确的文档。

    char report[8] = {0};
    uint16_t x_access = 10000;
    uint16_t y_access = 10000;

    report[0] = 0x01; //reportid
    report[1] = 0x3;   //statuss
    report[2] = LOWBYTE(x_access);  //x low byte
    report[3] = HIGHBYTE(x_access); //x high byte
    report[4] = LOWBYTE(y_access);  //y low byte
    report[5] = HIGHBYTE(y_access); //y high byte
    report[6] = 0x65;               //touch parsing time low byte 
    report[7] = 0x00;               //touch parsing time high byte
  //report[8] = 1                   //this doesn't have any impact (touch count)

我使用过的有用链接

1. https://www.usb.org/hid
2. http://ww1.microchip.com/downloads/en/DeviceDoc/mXT1386E_2v9_Datasheet_BX.pdf
3. https://www.interelectronix.com/de/sis95xx-series-touch-data-format.html
4. http://ww1.microchip.com/downloads/en/devicedoc/41606b.pdf

提前感谢您的帮助

Answer 1

使用RDD! HID Report Descriptor Decoder 工具，我们可以轻松地从Microsoft provided touchscreen "Sample Report Descriptor" 生成C 结构：

//--------------------------------------------------------------------------------
// Digitizer Device Page inputReport 01 (Device --> Host)
//--------------------------------------------------------------------------------

typedef struct
{
  uint8_t  reportId;                                 // Report ID = 0x01 (1)
                                                     // Collection: CA:TouchScreen CL:Finger
  uint8_t  DIG_TouchScreenFingerTipSwitch : 1;       // Usage 0x000D0042: Tip Switch, Value = 0 to 1
  uint8_t  : 7;                                      // Pad
  uint8_t  DIG_TouchScreenFingerContactIdentifier;   // Usage 0x000D0051: Contact Identifier, Value = 0 to 1
  uint16_t GD_TouchScreenFingerX[2];                 // Usage 0x00010030: X, Value = 0 to 4095, Physical = Value x 241 / 819 in 10⁻² inch units
  uint16_t GD_TouchScreenFingerY[2];                 // Usage 0x00010031: Y, Value = 0 to 4095, Physical = Value x 302 / 1365 in 10⁻² inch units
  uint16_t DIG_TouchScreenFingerWidth;               // Usage 0x000D0048: Width, Value = 0 to 4095, Physical = Value x 302 / 1365 in 10⁻² inch units
  uint16_t DIG_TouchScreenFingerHeight;              // Usage 0x000D0049: Height, Value = 0 to 4095, Physical = Value x 302 / 1365 in 10⁻² inch units
  uint16_t DIG_TouchScreenFingerAzimuth;             // Usage 0x000D003F: Azimuth, Value = 0 to 62831, Physical = Value in 10⁻⁴ rad units
  uint8_t  DIG_TouchScreenFingerTipSwitch_1 : 1;     // Usage 0x000D0042: Tip Switch, Value = 0 to 1, Physical = Value x 62831 in 10⁻⁴ rad units
  uint8_t  : 7;                                      // Pad
  uint8_t  DIG_TouchScreenFingerContactIdentifier_1; // Usage 0x000D0051: Contact Identifier, Value = 0 to 1, Physical = Value x 62831 in 10⁻⁴ rad units
  uint16_t GD_TouchScreenFingerX_1[2];               // Usage 0x00010030: X, Value = 0 to 4095, Physical = Value x 241 / 819 in 10⁻² inch units
  uint16_t GD_TouchScreenFingerY_1[2];               // Usage 0x00010031: Y, Value = 0 to 4095, Physical = Value x 302 / 1365 in 10⁻² inch units
  uint16_t DIG_TouchScreenFingerWidth_1;             // Usage 0x000D0048: Width, Value = 0 to 4095, Physical = Value x 302 / 1365 in 10⁻² inch units
  uint16_t DIG_TouchScreenFingerHeight_1;            // Usage 0x000D0049: Height, Value = 0 to 4095, Physical = Value x 302 / 1365 in 10⁻² inch units
  uint16_t DIG_TouchScreenFingerAzimuth_1;           // Usage 0x000D003F: Azimuth, Value = 0 to 62831, Physical = Value in 10⁻⁴ rad units
                                                     // Collection: CA:TouchScreen
  uint16_t DIG_TouchScreenRelativeScanTime;          // Usage 0x000D0056: Relative Scan Time, Value = 0 to 65535, Physical = Value in 10⁻⁴ s units
  uint8_t  DIG_TouchScreenContactCount;              // Usage 0x000D0054: Contact Count, Value = 0 to 127, Physical = Value x 65535 / 127 in 10⁻⁴ s units
} inputReport01_t;