tinyusb库具体使用HID的C语言例子

以下是一个使用TinyUSB库的C语言HID例子，它实现了将按键状态发送到计算机：

#include "tusb.h"

#define KEYBOARD_REPORT_ID      1
#define KEYBOARD_MODIFIER_LEFT  (1 << 0)
#define KEYBOARD_MODIFIER_RIGHT (1 << 1)

#define KEYBOARD_KEY_A          0x04
#define KEYBOARD_KEY_B          0x05
#define KEYBOARD_KEY_C          0x06
#define KEYBOARD_KEY_D          0x07
#define KEYBOARD_KEY_E          0x08
#define KEYBOARD_KEY_F          0x09
#define KEYBOARD_KEY_G          0x0a
#define KEYBOARD_KEY_H          0x0b
#define KEYBOARD_KEY_I          0x0c
#define KEYBOARD_KEY_J          0x0d
#define KEYBOARD_KEY_K          0x0e
#define KEYBOARD_KEY_L          0x0f
#define KEYBOARD_KEY_M          0x10
#define KEYBOARD_KEY_N          0x11
#define KEYBOARD_KEY_O          0x12
#define KEYBOARD_KEY_P          0x13
#define KEYBOARD_KEY_Q          0x14
#define KEYBOARD_KEY_R          0x15
#define KEYBOARD_KEY_S          0x16
#define KEYBOARD_KEY_T          0x17
#define KEYBOARD_KEY_U          0x18
#define KEYBOARD_KEY_V          0x19
#define KEYBOARD_KEY_W          0x1a
#define KEYBOARD_KEY_X          0x1b
#define KEYBOARD_KEY_Y          0x1c
#define KEYBOARD_KEY_Z          0x1d

static const uint8_t keyboard_report_descriptor[] =
{
    TUD_HID_REPORT_DESCRIPTOR_KEYBOARD( HID_REPORT_ID(KEYBOARD_REPORT_ID),
                                         HID_REPORT_ITEM_USAGE_PAGE( HID_USAGE_PAGE_GENERIC_DESKTOP ),
                                         HID_REPORT_ITEM_USAGE_MINIMUM( 0x00 ),
                                         HID_REPORT_ITEM_USAGE_MAXIMUM( 0x65 ),
                                         HID_REPORT_ITEM_LOGICAL_MINIMUM( 0x00 ),
                                         HID_REPORT_ITEM_LOGICAL_MAXIMUM( 0x01 ),
                                         HID_REPORT_ITEM_COLLECTION_APPLICATION( HID_REPORT_ITEM_COLLECTION_DATA, HID_REPORT_ITEM_COLLECTION_PHYSICAL ),
                                             HID_REPORT_ITEM_USAGE_PAGE( HID_USAGE_PAGE_KEYBOARD ),
                                             HID_REPORT_ITEM_USAGE_MINIMUM( 0x00 ),
                                             HID_REPORT_ITEM_USAGE_MAXIMUM( 0x65 ),
                                             HID_REPORT_ITEM_LOGICAL_MINIMUM( 0x00 ),
                                             HID_REPORT_ITEM_LOGICAL_MAXIMUM( 0x01 ),
                                             HID_REPORT_ITEM_REPORT_SIZE( 0x01 ),
                                             HID_REPORT_ITEM_REPORT_COUNT( 0x65 ),
                                             HID_REPORT_ITEM_INPUT( HID_CONST | HID_DATA | HID_VARIABLE | HID_ABSOLUTE ),
                                         HID_REPORT_ITEM_END_COLLECTION,
    ),
};

static inline uint8_t keyboard_report_find_key(uint8_t keycode)
{
    switch (keycode)
    {
        case 'a':
        case 'A':
            return KEYBOARD_KEY_A;
        case 'b':
        case 'B':
            return KEYBOARD_KEY_B;
        case 'c':
        case 'C':
            return KEYBOARD_KEY_C;
        case 'd':
        case 'D':
            return KEYBOARD_KEY_D;
        case 'e':
        case 'E':
            return KEYBOARD_KEY_E;
        case 'f':
        case 'F':
            return KEYBOARD_KEY_F;
        case 'g':
        case 'G':
            return KEYBOARD_KEY_G;
        case 'h':
        case 'H':
            return KEYBOARD_KEY_H;
        case 'i':
        case 'I':
            return KEYBOARD_KEY_I;
        case 'j':
        case 'J':
            return KEYBOARD_KEY_J;
        case 'k':
        case 'K':
            return KEYBOARD_KEY_K;
        case 'l':
        case 'L':
            return KEYBOARD_KEY_L;
        case 'm':
        case 'M':
            return KEYBOARD_KEY_M;
        case 'n':
        case 'N':
            return KEYBOARD_KEY_N;
        case 'o':
        case 'O':
            return KEYBOARD_KEY_O;
        case 'p':
        case 'P':
            return KEYBOARD_KEY_P;
        case 'q':
        case 'Q':
            return KEYBOARD_KEY_Q;
        case 'r':
        case 'R':
            return KEYBOARD_KEY_R;
        case 's':
        case 'S':
            return KEYBOARD_KEY_S;
        case 't':
        case 'T':
            return KEYBOARD_KEY_T;
        case 'u':
        case 'U':
            return KEYBOARD_KEY_U;
        case 'v':
        case 'V':
            return KEYBOARD_KEY_V;
        case 'w':
        case 'W':
            return KEYBOARD_KEY_W;
        case 'x':
        case 'X':
            return KEYBOARD_KEY_X;
        case 'y':
        case 'Y':
            return KEYBOARD_KEY_Y;
        case 'z':
        case 'Z':
            return KEYBOARD_KEY_Z;
        default:
            return 0;
    }
}

void tud_hid_report_complete_cb(uint8_t instance, uint8_t report_id, uint8_t status)
{
    (void) instance;
    (void) report_id;
    (void) status;
}

int main(void)
{
    tusb_init();
    while (1)
    {
        tud_task();
        if (tud_hid_ready())
        {
            uint8_t keycode = getchar();
            if (keycode)
            {
                uint8_t keycode_id = keyboard_report_find_key(keycode);
                if (keycode_id)
                {
                    uint8_t report[8];
                    memset(report, 0, sizeof(report));
                    report[0] = KEYBOARD_REPORT_ID;
                    report[1] = KEYBOARD_MODIFIER_LEFT;
                    report[2] = keycode_id;
                    tud_hid_report(0, report, sizeof(report));
                }
            }
        }
    }
    return 0;
}

此代码示例使用了TinyUSB库的HID模块。在主函数中，`tusb_init()`函数初始化TinyUSB库，然后在`while`循环中调用`tud_task()`函数以处理USB任务。当HID模块已就绪时，程序会等待用户输入，并将按键状态打包成HID报告发送到计算机。键盘报告的描述符存储在`keyboard_report_descriptor`数组中，并使用TinyUSB库的`TUD_HID_REPORT_DESCRIPTOR_KEYBOARD()`宏生成。

此代码示例还实现了一个`keyboard_report_find_key()`函数，该函数将ASCII字符转换为HID键码。在`main()`函数中，程序等待用户输入，并使用此函数将输入字符转换为HID键码。如果键码存在，则程序将创建一个包含键码和修饰符信息的HID报告，并使用`tud_hid_report()`函数将其发送到计算机。