The VKVM control and periphery communicate via USB CDC like a serial device.
This makes it necessary to use a proper framing protocol.
All related function to this are included in Framing.hpp.
The framing is done similar to RFC 1662 with 0x7E as start/stop byte,
0x7D as escape byte, which indicates that the next byte is XOR 0x20 to quote bytes
used for framing. The actual frame has the following structure with all bytes except
STX/ETX being properly quoted.
| Byte | Size | Field | Description |
|---|---|---|---|
| 0 | 1 | STX | Start of frame (0x7E). |
| 1 | 1 | SEQ | Frame sequence number. |
| 2 | N-5 | DATA | User payload. |
| N-3 | 2 | CRC16 | CRC16 over the unquoted payload. |
| N-1 | 1 | ETX | End of frame (0x7E). |
CRC16-CCITT like in HDLC (see RFC 1662) is being used here.
| Field | Name | Value | Description |
|---|---|---|---|
| RES | S_OK | 0x00 | The request has been processed. |
| RES | I_USB_STATE_UPDATE | 0x40 | Updated event of the USB periphery state. |
| RES | I_LED_UPDATE | 0x41 | Updated event of the LED states. |
| RES | D_MESSAGE | 0x60 | Debug message. |
| RES | E_BROKEN_FRAME | 0x80 | Received broken frame. |
| RES | E_UNSUPPORTED_REQ_TYPE | 0x81 | Received unsupported request type. |
| RES | E_INVALID_REQ_TYPE | 0x82 | Received invalid request type. |
| RES | E_INVALID_FIELD_VALUE | 0x83 | Received invalid field value. |
| RES | E_HOST_WRITE_ERROR | 0x85 | Failed write to remote host. |
| REQ | GET_PROTOCOL_VERSION | 0x00 | Request protocol version. |
| REQ | GET_ALIVE | 0x01 | Request keep alive. |
| REQ | GET_USB_STATE | 0x02 | Request USB periphery state. |
| REQ | GET_KEYBOARD_LEDS | 0x03 | Request keyboard LED states. |
| REQ | SET_KEYBOARD_DOWN | 0x04 | Push keyboard key down. |
| REQ | SET_KEYBOARD_UP | 0x05 | Release keyboard key. |
| REQ | SET_KEYBOARD_ALL_UP | 0x06 | Release all keyboard keys. |
| REQ | SET_KEYBOARD_PUSH | 0x07 | Single push keyboard key. |
| REQ | SET_KEYBOARD_WRITE | 0x08 | Write keyboard keys. |
| REQ | SET_MOUSE_BUTTON_DOWN | 0x09 | Push mouse button down. |
| REQ | SET_MOUSE_BUTTON_UP | 0x0A | Release mouse button. |
| REQ | SET_MOUSE_BUTTON_ALL_UP | 0x0B | Release all mouse buttons. |
| REQ | SET_MOUSE_BUTTON_PUSH | 0x0C | Single push mouse button. |
| REQ | SET_MOUSE_MOVE_ABS | 0x0D | Absolute mouse movement. |
| REQ | SET_MOUSE_MOVE_REL | 0x0E | Relative mouse movement. |
| REQ | SET_MOUSE_SCROLL | 0x0F | Mouse wheel change. |
| USB | USBSTATE_OFF | 0x00 | USB periphery is physically disconnected. |
| USB | USBSTATE_ON | 0x01 | USB periphery is physically connected. |
| USB | USBSTATE_CONFIGURED | 0x02 | USB periphery is configured by host. |
| USB | USBSTATE_ON_CONFIGURED | 0x03 | USB periphery is fully functional. |
| LED¹ | USBLED_NUM_LOCK | 0x01 | Num lock key status. |
| LED¹ | USBLED_CAPS_LOCK | 0x02 | Caps lock key status. |
| LED¹ | USBLED_SCROLL_LOCK | 0x04 | Scroll lock key status. |
| LED¹ | USBLED_COMPOSE | 0x08 | Composition mode enabled status. |
| LED¹ | USBLED_KANA | 0x10 | Kana key status. |
| LED¹ | USBLED_POWER | 0x20 | Power status. |
| LED¹ | USBLED_SHIFT | 0x40 | Shift function status. |
| LED¹ | USBLED_DO_NOT_DISTURB | 0x80 | Shift function status. |
| KEY² | USBKEY_NO_EVENT | 0x00 | No keyboard event indicator. |
| KEY² | USBKEY_ERROR_ROLL_OVER | 0x01 | Keyboard ErrorRollOver |
| KEY² | USBKEY_POST_FAIL | 0x02 | Keyboard POSTFail |
| KEY² | USBKEY_ERROR_UNDEFINED | 0x03 | Keyboard ErrorUndefined |
| KEY² | USBKEY_A | 0x04 | Keyboard a and A |
| KEY² | USBKEY_B | 0x05 | Keyboard b and B |
| KEY² | USBKEY_C | 0x06 | Keyboard c and C |
| KEY² | USBKEY_D | 0x07 | Keyboard d and D |
| KEY² | USBKEY_E | 0x08 | Keyboard e and E |
| KEY² | USBKEY_F | 0x09 | Keyboard f and F |
| KEY² | USBKEY_G | 0x0A | Keyboard g and G |
| KEY² | USBKEY_H | 0x0B | Keyboard h and H |
| KEY² | USBKEY_I | 0x0C | Keyboard i and I |
| KEY² | USBKEY_J | 0x0D | Keyboard j and J |
| KEY² | USBKEY_K | 0x0E | Keyboard k and K |
| KEY² | USBKEY_L | 0x0F | Keyboard l and L |
| KEY² | USBKEY_M | 0x10 | Keyboard m and M |
| KEY² | USBKEY_N | 0x11 | Keyboard n and N |
| KEY² | USBKEY_O | 0x12 | Keyboard o and O |
| KEY² | USBKEY_P | 0x13 | Keyboard p and P |
| KEY² | USBKEY_Q | 0x14 | Keyboard q and Q |
| KEY² | USBKEY_R | 0x15 | Keyboard r and R |
| KEY² | USBKEY_S | 0x16 | Keyboard s and S |
| KEY² | USBKEY_T | 0x17 | Keyboard t and T |
| KEY² | USBKEY_U | 0x18 | Keyboard u and U |
| KEY² | USBKEY_V | 0x19 | Keyboard v and V |
| KEY² | USBKEY_W | 0x1A | Keyboard w and W |
| KEY² | USBKEY_X | 0x1B | Keyboard x and X |
| KEY² | USBKEY_Y | 0x1C | Keyboard y and Y |
| KEY² | USBKEY_Z | 0x1D | Keyboard z and Z |
| KEY² | USBKEY_1 | 0x1E | Keyboard 1 and ! |
| KEY² | USBKEY_2 | 0x1F | Keyboard 2 and @ |
| KEY² | USBKEY_3 | 0x20 | Keyboard 3 and # |
| KEY² | USBKEY_4 | 0x21 | Keyboard 4 and $ |
| KEY² | USBKEY_5 | 0x22 | Keyboard 5 and % |
| KEY² | USBKEY_6 | 0x23 | Keyboard 6 and ^ |
| KEY² | USBKEY_7 | 0x24 | Keyboard 7 and & |
| KEY² | USBKEY_8 | 0x25 | Keyboard 8 and * |
| KEY² | USBKEY_9 | 0x26 | Keyboard 9 and ( |
| KEY² | USBKEY_0 | 0x27 | Keyboard 0 and ) |
| KEY² | USBKEY_ENTER | 0x28 | Keyboard Return (ENTER) |
| KEY² | USBKEY_ESCAPE | 0x29 | Keyboard ESCAPE |
| KEY² | USBKEY_BACKSPACE | 0x2A | Keyboard DELETE (Backspace) |
| KEY² | USBKEY_TAB | 0x2B | Keyboard Tab |
| KEY² | USBKEY_SPACE | 0x2C | Keyboard Spacebar |
| KEY² | USBKEY_MINUS | 0x2D | Keyboard - and (underscore) |
| KEY² | USBKEY_EQUAL | 0x2E | Keyboard = and + |
| KEY² | USBKEY_OPEN_BRACKET | 0x2F | Keyboard [ and { |
| KEY² | USBKEY_CLOSE_BRACKET | 0x30 | Keyboard ] and } |
| KEY² | USBKEY_BACKSLASH | 0x31 | Keyboard \ and | |
| KEY² | USBKEY_NON_US_HASH | 0x32 | Keyboard Non-US # and ˜ |
| KEY² | USBKEY_SEMICOLON | 0x33 | Keyboard ; and : |
| KEY² | USBKEY_APOSTROPHE | 0x34 | Keyboard ‘ and “ |
| KEY² | USBKEY_ACCENT | 0x35 | Keyboard Grave Accent and Ti |
| KEY² | USBKEY_COMMA | 0x36 | Keyboard , and < |
| KEY² | USBKEY_PERIOD | 0x37 | Keyboard . and > |
| KEY² | USBKEY_SLASH | 0x38 | Keyboard / and ? |
| KEY² | USBKEY_CAPS_LOCK | 0x39 | Keyboard Caps Lock |
| KEY² | USBKEY_F1 | 0x3A | Keyboard F1 |
| KEY² | USBKEY_F2 | 0x3B | Keyboard F2 |
| KEY² | USBKEY_F3 | 0x3C | Keyboard F3 |
| KEY² | USBKEY_F4 | 0x3D | Keyboard F4 |
| KEY² | USBKEY_F5 | 0x3E | Keyboard F5 |
| KEY² | USBKEY_F6 | 0x3F | Keyboard F6 |
| KEY² | USBKEY_F7 | 0x40 | Keyboard F7 |
| KEY² | USBKEY_F8 | 0x41 | Keyboard F8 |
| KEY² | USBKEY_F9 | 0x42 | Keyboard F9 |
| KEY² | USBKEY_F10 | 0x43 | Keyboard F10 |
| KEY² | USBKEY_F11 | 0x44 | Keyboard F11 |
| KEY² | USBKEY_F12 | 0x45 | Keyboard F12 |
| KEY² | USBKEY_PRINT_SCREEN | 0x46 | Keyboard PrintScreen |
| KEY² | USBKEY_SCROLL_LOCK | 0x47 | Keyboard Scroll Lock |
| KEY² | USBKEY_PAUSE | 0x48 | Keyboard Pause |
| KEY² | USBKEY_INSERT | 0x49 | Keyboard Insert |
| KEY² | USBKEY_HOME | 0x4A | Keyboard Home |
| KEY² | USBKEY_PAGE_UP | 0x4B | Keyboard PageUp |
| KEY² | USBKEY_DELETE | 0x4C | Keyboard Delete Forward |
| KEY² | USBKEY_END | 0x4D | Keyboard End |
| KEY² | USBKEY_PAGE_DOWN | 0x4E | Keyboard PageDown |
| KEY² | USBKEY_RIGHT_ARROW | 0x4F | Keyboard RightArrow |
| KEY² | USBKEY_LEFT_ARROW | 0x50 | Keyboard LeftArrow |
| KEY² | USBKEY_DOWN_ARROW | 0x51 | Keyboard DownArrow |
| KEY² | USBKEY_UP_ARROW | 0x52 | Keyboard UpArrow |
| KEY² | USBKEY_NUM_LOCK | 0x53 | Keypad Num Lock and Clear |
| KEY² | USBKEY_KP_DIVIDE | 0x54 | Keypad / |
| KEY² | USBKEY_KP_MULTIPLY | 0x55 | Keypad * |
| KEY² | USBKEY_KP_SUBTRACT | 0x56 | Keypad - |
| KEY² | USBKEY_KP_ADD | 0x57 | Keypad + |
| KEY² | USBKEY_KP_ENTER | 0x58 | Keypad ENTER |
| KEY² | USBKEY_KP_1 | 0x59 | Keypad 1 and End |
| KEY² | USBKEY_KP_2 | 0x5A | Keypad 2 and Down Arrow |
| KEY² | USBKEY_KP_3 | 0x5B | Keypad 3 and PageDn |
| KEY² | USBKEY_KP_4 | 0x5C | Keypad 4 and Left Arrow |
| KEY² | USBKEY_KP_5 | 0x5D | Keypad 5 |
| KEY² | USBKEY_KP_6 | 0x5E | Keypad 6 and Right Arrow |
| KEY² | USBKEY_KP_7 | 0x5F | Keypad 7 and Home |
| KEY² | USBKEY_KP_8 | 0x60 | Keypad 8 and Up Arrow |
| KEY² | USBKEY_KP_9 | 0x61 | Keypad 9 and PageUp |
| KEY² | USBKEY_KP_0 | 0x62 | Keypad 0 and Insert |
| KEY² | USBKEY_KP_DECIMAL | 0x63 | Keypad . and Delete |
| KEY² | USBKEY_NON_US_BACKSLASH | 0x64 | Keyboard Non-US \ and | |
| KEY² | USBKEY_APPLICATION | 0x65 | Keyboard Application |
| KEY² | USBKEY_POWER | 0x66 | Keyboard Power |
| KEY² | USBKEY_KP_EQUAL | 0x67 | Keypad = |
| KEY² | USBKEY_F13 | 0x68 | Keyboard F13 |
| KEY² | USBKEY_F14 | 0x69 | Keyboard F14 |
| KEY² | USBKEY_F15 | 0x6A | Keyboard F15 |
| KEY² | USBKEY_F16 | 0x6B | Keyboard F16 |
| KEY² | USBKEY_F17 | 0x6C | Keyboard F17 |
| KEY² | USBKEY_F18 | 0x6D | Keyboard F18 |
| KEY² | USBKEY_F19 | 0x6E | Keyboard F19 |
| KEY² | USBKEY_F20 | 0x6F | Keyboard F20 |
| KEY² | USBKEY_F21 | 0x70 | Keyboard F21 |
| KEY² | USBKEY_F22 | 0x71 | Keyboard F22 |
| KEY² | USBKEY_F23 | 0x72 | Keyboard F23 |
| KEY² | USBKEY_F24 | 0x73 | Keyboard F24 |
| KEY² | USBKEY_EXECUTE | 0x74 | Keyboard Execute |
| KEY² | USBKEY_HELP | 0x75 | Keyboard Help |
| KEY² | USBKEY_MENU | 0x76 | Keyboard Menu |
| KEY² | USBKEY_SELECT | 0x77 | Keyboard Select |
| KEY² | USBKEY_STOP | 0x78 | Keyboard Stop |
| KEY² | USBKEY_AGAIN | 0x79 | Keyboard Again |
| KEY² | USBKEY_UNDO | 0x7A | Keyboard Undo |
| KEY² | USBKEY_CUT | 0x7B | Keyboard Cut |
| KEY² | USBKEY_COPY | 0x7C | Keyboard Copy |
| KEY² | USBKEY_PASTE | 0x7D | Keyboard Paste |
| KEY² | USBKEY_FIND | 0x7E | Keyboard Find |
| KEY² | USBKEY_MUTE | 0x7F | Keyboard Mute |
| KEY² | USBKEY_VOLUME_UP | 0x80 | Keyboard Volume Up |
| KEY² | USBKEY_VOLUME_DOWN | 0x81 | Keyboard Volume Down |
| KEY² | USBKEY_LOCKING_CAPS_LOCK | 0x82 | Keyboard Locking Caps Lock |
| KEY² | USBKEY_LOCKING_NUM_LOCK | 0x83 | Keyboard Locking Num Lock |
| KEY² | USBKEY_LOCKING_SCROLL_LOCK | 0x84 | Keyboard Locking Scroll Lock |
| KEY² | USBKEY_KP_COMMA | 0x85 | Keypad Comma |
| KEY² | USBKEY_KP_EQUAL_SIGN | 0x86 | Keypad Equal Sign |
| KEY² | USBKEY_INT_1 | 0x87 | Keyboard International1 |
| KEY² | USBKEY_INT_2 | 0x88 | Keyboard International2 |
| KEY² | USBKEY_INT_3 | 0x89 | Keyboard International3 |
| KEY² | USBKEY_INT_4 | 0x8A | Keyboard International4 |
| KEY² | USBKEY_INT_5 | 0x8B | Keyboard International5 |
| KEY² | USBKEY_INT_6 | 0x8C | Keyboard International6 |
| KEY² | USBKEY_INT_7 | 0x8D | Keyboard International7 |
| KEY² | USBKEY_INT_8 | 0x8E | Keyboard International8 |
| KEY² | USBKEY_INT_9 | 0x8F | Keyboard International9 |
| KEY² | USBKEY_IME_KANA | 0x88 | Keyboard International1 |
| KEY² | USBKEY_IME_CONVERT | 0x8A | Keyboard International2 |
| KEY² | USBKEY_IME_NONCONVERT | 0x8B | Keyboard International3 |
| KEY² | USBKEY_LANG_1 | 0x90 | Keyboard LANG1 |
| KEY² | USBKEY_LANG_2 | 0x91 | Keyboard LANG2 |
| KEY² | USBKEY_LANG_3 | 0x92 | Keyboard LANG3 |
| KEY² | USBKEY_LANG_4 | 0x93 | Keyboard LANG4 |
| KEY² | USBKEY_LANG_5 | 0x94 | Keyboard LANG5 |
| KEY² | USBKEY_LANG_6 | 0x95 | Keyboard LANG6 |
| KEY² | USBKEY_LANG_7 | 0x96 | Keyboard LANG7 |
| KEY² | USBKEY_LANG_8 | 0x97 | Keyboard LANG8 |
| KEY² | USBKEY_LANG_9 | 0x98 | Keyboard LANG9 |
| KEY² | USBKEY_ALT_ERASE | 0x99 | Keyboard Alternate Erase |
| KEY² | USBKEY_ATTN | 0x9A | Keyboard SysReq/Attention |
| KEY² | USBKEY_CANCEL | 0x9B | Keyboard Cancel |
| KEY² | USBKEY_CLEAR | 0x9C | Keyboard Clear |
| KEY² | USBKEY_PRIOR | 0x9D | Keyboard Prior |
| KEY² | USBKEY_RETURN | 0x9E | Keyboard Return |
| KEY² | USBKEY_SEPARATOR | 0x9F | Keyboard Separator |
| KEY² | USBKEY_OUT | 0xA0 | Keyboard Out |
| KEY² | USBKEY_OPER | 0xA1 | Keyboard Oper |
| KEY² | USBKEY_CLEAR_AGAIN | 0xA2 | Keyboard Clear/Again |
| KEY² | USBKEY_CRSEL_PROPS | 0xA3 | Keyboard CrSel/Props |
| KEY² | USBKEY_EXSEL | 0xA4 | Keyboard ExSel |
| KEY² | USBKEY_KP_00 | 0xB0 | Keypad 00 |
| KEY² | USBKEY_KP_000 | 0xB1 | Keypad 000 |
| KEY² | USBKEY_THOUSENDS_SEP | 0xB2 | Thousands Separator |
| KEY² | USBKEY_DECIMAL_SEP | 0xB3 | Decimal Separator |
| KEY² | USBKEY_CURRENCY_UNIT | 0xB4 | Currency Unit |
| KEY² | USBKEY_CURRENCY_SUB_UNIT | 0xB5 | Currency Sub-unit |
| KEY² | USBKEY_KP_OPEN_BRACKET | 0xB6 | Keypad ( |
| KEY² | USBKEY_KP_CLOSE_BRACKET | 0xB7 | Keypad ) |
| KEY² | USBKEY_KP_OPEN_CURLY_BRACKET | 0xB8 | Keypad { |
| KEY² | USBKEY_KP_CLOSE_CURLY_BRACKET | 0xB9 | Keypad } |
| KEY² | USBKEY_KP_TAB | 0xBA | Keypad Tab |
| KEY² | USBKEY_KP_BACKSPACE | 0xBB | Keypad Backspace |
| KEY² | USBKEY_KP_A | 0xBC | Keypad A |
| KEY² | USBKEY_KP_B | 0xBD | Keypad B |
| KEY² | USBKEY_KP_C | 0xBE | Keypad C |
| KEY² | USBKEY_KP_D | 0xBF | Keypad D |
| KEY² | USBKEY_KP_E | 0xC0 | Keypad E |
| KEY² | USBKEY_KP_F | 0xC1 | Keypad F |
| KEY² | USBKEY_KP_XOR | 0xC2 | Keypad XOR |
| KEY² | USBKEY_KP_CARET | 0xC3 | Keypad ^ |
| KEY² | USBKEY_KP_PERCENT | 0xC4 | Keypad % |
| KEY² | USBKEY_KP_LESS | 0xC5 | Keypad < |
| KEY² | USBKEY_KP_GREATER | 0xC6 | Keypad > |
| KEY² | USBKEY_KP_AND | 0xC7 | Keypad & |
| KEY² | USBKEY_KP_AND2 | 0xC8 | Keypad && |
| KEY² | USBKEY_KP_OR | 0xC9 | Keypad | |
| KEY² | USBKEY_KP_OR2 | 0xCA | Keypad || |
| KEY² | USBKEY_KP_COLON | 0xCB | Keypad : |
| KEY² | USBKEY_KP_HASH | 0xCC | Keypad # |
| KEY² | USBKEY_KP_SPACE | 0xCD | Keypad Space |
| KEY² | USBKEY_KP_AT | 0xCE | Keypad @ |
| KEY² | USBKEY_KP_EXCLAMATION | 0xCF | Keypad ! |
| KEY² | USBKEY_KP_MEM_STORE | 0xD0 | Keypad Memory Store |
| KEY² | USBKEY_KP_MEM_RECALL | 0xD1 | Keypad Memory Recall |
| KEY² | USBKEY_KP_MEM_CLEAR | 0xD2 | Keypad Memory Clear |
| KEY² | USBKEY_KP_MEM_ADD | 0xD3 | Keypad Memory Add |
| KEY² | USBKEY_KP_MEM_SUB | 0xD4 | Keypad Memory Subtract |
| KEY² | USBKEY_KP_MEM_MUL | 0xD5 | Keypad Memory Multiply |
| KEY² | USBKEY_KP_MEM_DIV | 0xD6 | Keypad Memory Divide |
| KEY² | USBKEY_KP_PLUS_MINUS | 0xD7 | Keypad +/- |
| KEY² | USBKEY_KP_CLEAR | 0xD8 | Keypad Clear |
| KEY² | USBKEY_KP_CLEAR_ENTRY | 0xD9 | Keypad Clear Entry |
| KEY² | USBKEY_KP_BIN | 0xDA | Keypad Binary |
| KEY² | USBKEY_KP_OCT | 0xDB | Keypad Octal |
| KEY² | USBKEY_KP_DEC | 0xDC | Keypad Decimal |
| KEY² | USBKEY_KP_HEX | 0xDD | Keypad Hexadecimal |
| KEY² | USBKEY_LEFT_CONTROL | 0xE0 | Keyboard LeftControl |
| KEY² | USBKEY_LEFT_SHIFT | 0xE1 | Keyboard LeftShift |
| KEY² | USBKEY_LEFT_ALT | 0xE2 | Keyboard LeftAlt |
| KEY² | USBKEY_LEFT_GUI | 0xE3 | Keyboard Left GUI |
| KEY² | USBKEY_RIGHT_CONTROL | 0xE4 | Keyboard RightControl |
| KEY² | USBKEY_RIGHT_SHIFT | 0xE5 | Keyboard RightShift |
| KEY² | USBKEY_RIGHT_ALT | 0xE6 | Keyboard RightAlt |
| KEY² | USBKEY_RIGHT_GUI | 0xE7 | Keyboard Right GUI |
| MOD | USBWRITE_LEFT_CONTROL | 0x01 | Left control key is being pressed. |
| MOD | USBWRITE_LEFT_SHIFT | 0x02 | Left shift key is being pressed. |
| MOD | USBWRITE_LEFT_ALT | 0x04 | Left alt key is being pressed. |
| MOD | USBWRITE_RIGHT_CONTROL | 0x08 | Right control key is being pressed. |
| MOD | USBWRITE_RIGHT_SHIFT | 0x10 | Right shift key is being pressed. |
| MOD | USBWRITE_RIGHT_ALT | 0x20 | Right alt key is being pressed. |
| MOD | USBWRITE_RIGHT_NUM_LOCK | 0x40 | Num lock is active. |
| MOD | USBWRITE_RIGHT_KANA | 0x80 | Kana is being enabled. |
| BUTTON³ | USBBUTTON_LEFT | 0x01 | Button 1 (primary/trigger) |
| BUTTON³ | USBBUTTON_RIGHT | 0x02 | Button 2 (secondary) |
| BUTTON³ | USBBUTTON_MIDDLE | 0x04 | Button 3 (tertiary) |
1) See also HID Usage Tables for USB v1.2 ch. 11 for LED values.
2) See also HID Usage Tables for USB v1.2 ch. 10 for keyboard key values.
3) See also HID Usage Tables for USB v1.2 ch. 12 for mouse button values.
| Size | C Type | Name | Description |
|---|---|---|---|
| 1 | uint8_t | KEY | Keyboard key values. Up to 6 |
| 1 | uint8_t | NKEY | Number of keys processed. |
| 1 | uint8_t | MOD | Keyboard key modifier. |
| 1 | uint8_t | USB | USB periphery state. |
| 1 | uint8_t | LED | Keyboard LED bits. |
| 1 | uint8_t | BUTTON | Mouse button value. |
| 1 | uint8_t | NBUTTON | Number of buttons processed. |
| 1 | int8_t | REL_X | Relative mouse x coordinate. |
| 1 | int8_t | REL_Y | Relative mouse y coordinate. |
| 1 | int8_t | WHEEL | Relative mouse wheel change. |
| 2 | int16_t | ABS_X | Absolute mouse x coordinate. |
| 2 | int16_t | ABS_Y | Absolute mouse y coordinate. |
| 2 | uint16_t | VER | Protocol version (0x0100). |
The user payload is structured as following for requests (control ⇨ periphery).
| Byte | Size | Field | Description |
|---|---|---|---|
| 0 | 1 | REQ | Request type. |
| 1 | N-1 | FIELDS | Request fields (optional). |
The user payload is structured as following for responses (control ⇦ periphery).
| Byte | Size | Field | Description |
|---|---|---|---|
| 0 | 1 | RES | Response type. |
| 1 | N-1 | FIELDS | Response fields (optional). |
The following request/response messages are defined including unsolicited responses.
| Name | Request Fields | Response Fields |
|---|---|---|
| GET_PROTOCOL_VERSION | - | VER |
| GET_ALIVE | - | - |
| GET_USB_STATE | - | USB |
| GET_KEYBOARD_LEDS | - | LED |
| SET_KEYBOARD_DOWN | KEY[1..6] | - |
| SET_KEYBOARD_UP | KEY[1..6] | - |
| SET_KEYBOARD_ALL_UP | - | - |
| SET_KEYBOARD_PUSH | KEY[0..N]¹ | NKEY |
| SET_KEYBOARD_WRITE | MOD, KEY[0..N]¹ | NKEY |
| SET_MOUSE_BUTTON_DOWN | BUTTON[1..3] | - |
| SET_MOUSE_BUTTON_UP | BUTTON[1..3] | - |
| SET_MOUSE_BUTTON_ALL_UP | - | - |
| SET_MOUSE_BUTTON_PUSH | BUTTON[0..N]¹ | NBUTTON |
| SET_MOUSE_MOVE_ABS | ABS_X, ABS_Y | - |
| SET_MOUSE_MOVE_REL | REL_X, REL_Y | - |
| SET_MOUSE_SCROLL | WHEEL | - |
| USB state update interrupt² | - | USB |
| LED update interrupt³ | - | LED |
| DEBUG message⁴ | - |
1) The maximum frame size is 256 bytes which limits the maximum number of keys/buttons per request.
2) The USB state update interrupt has the sequence number 0 and response type I_USB_STATE_UPDATE.
3) The LED update interrupt has the sequence number 0 and response type I_LED_UPDATE.
4) The DEBUG message has the sequence number 0 and response type D_MESSAGE.