USB HID Keyboard for Pico RP2040 with TinyUSB.
This is an adapted copy of the hid_composite example from TinyUSB showing how to build with TinyUSB when using the Raspberry Pi Pico SDK. This repository optimizes the REPORT_ID_KEYBOARD reports.
In keyboard.h a USB HID Keyboard report is created from pin inputs on the Pico.
Connect pico gpio pins to usb hid keyboard keys:
const static int num_pins = 11;
const PinKey pin_keys[num_pins] = { // map gpio pin to keycode
{ 2, HID_KEY_W },
{ 3, HID_KEY_A },
{ 4, HID_KEY_S },
{ 5, HID_KEY_D },
{ 16, HID_KEY_ARROW_UP },
{ 17, HID_KEY_ARROW_DOWN },
{ 18, HID_KEY_ARROW_LEFT },
{ 19, HID_KEY_ARROW_RIGHT },
{ 20, HID_KEY_ENTER },
{ 21, HID_KEY_SPACE },
{ 22, HID_KEY_SHIFT_LEFT }
};Make sure num_pins is equal to the amount of pin-key combinations specified in pin_keys. In this case, there's 11 connected pins. Note that the pico has 26 usable gpio pins.
A list of all the keycodes are at the end of this file.
The input pins use the internal pull up resistor on the pico. They read 1 when not pressed. Connect a pin to ground to generate a key press for that pin.
button
__
pin -----+ +----- ground
The pins are polled once every 10ms.
See Getting Started with the Raspberry Pi Pico and the README in the pico-sdk for information on getting up and running.
If the pico-sdk is in your $PATH, you can keep this repository anywhere. Cmake will probably find it.
Insert the Pico with the BOOTSEL button pressed. After it's mounted:
./uploadThe upload script will compile the code and upload the compiled firmware to the pico.
The HID keycodes are defined in pico-sdk/lib/tinyusb/src/class/hid/hid.h.
//--------------------------------------------------------------------+
// HID KEYCODE
//--------------------------------------------------------------------+
#define HID_KEY_NONE 0x00
#define HID_KEY_A 0x04
#define HID_KEY_B 0x05
#define HID_KEY_C 0x06
#define HID_KEY_D 0x07
#define HID_KEY_E 0x08
#define HID_KEY_F 0x09
#define HID_KEY_G 0x0A
#define HID_KEY_H 0x0B
#define HID_KEY_I 0x0C
#define HID_KEY_J 0x0D
#define HID_KEY_K 0x0E
#define HID_KEY_L 0x0F
#define HID_KEY_M 0x10
#define HID_KEY_N 0x11
#define HID_KEY_O 0x12
#define HID_KEY_P 0x13
#define HID_KEY_Q 0x14
#define HID_KEY_R 0x15
#define HID_KEY_S 0x16
#define HID_KEY_T 0x17
#define HID_KEY_U 0x18
#define HID_KEY_V 0x19
#define HID_KEY_W 0x1A
#define HID_KEY_X 0x1B
#define HID_KEY_Y 0x1C
#define HID_KEY_Z 0x1D
#define HID_KEY_1 0x1E
#define HID_KEY_2 0x1F
#define HID_KEY_3 0x20
#define HID_KEY_4 0x21
#define HID_KEY_5 0x22
#define HID_KEY_6 0x23
#define HID_KEY_7 0x24
#define HID_KEY_8 0x25
#define HID_KEY_9 0x26
#define HID_KEY_0 0x27
#define HID_KEY_ENTER 0x28
#define HID_KEY_ESCAPE 0x29
#define HID_KEY_BACKSPACE 0x2A
#define HID_KEY_TAB 0x2B
#define HID_KEY_SPACE 0x2C
#define HID_KEY_MINUS 0x2D
#define HID_KEY_EQUAL 0x2E
#define HID_KEY_BRACKET_LEFT 0x2F
#define HID_KEY_BRACKET_RIGHT 0x30
#define HID_KEY_BACKSLASH 0x31
#define HID_KEY_EUROPE_1 0x32
#define HID_KEY_SEMICOLON 0x33
#define HID_KEY_APOSTROPHE 0x34
#define HID_KEY_GRAVE 0x35
#define HID_KEY_COMMA 0x36
#define HID_KEY_PERIOD 0x37
#define HID_KEY_SLASH 0x38
#define HID_KEY_CAPS_LOCK 0x39
#define HID_KEY_F1 0x3A
#define HID_KEY_F2 0x3B
#define HID_KEY_F3 0x3C
#define HID_KEY_F4 0x3D
#define HID_KEY_F5 0x3E
#define HID_KEY_F6 0x3F
#define HID_KEY_F7 0x40
#define HID_KEY_F8 0x41
#define HID_KEY_F9 0x42
#define HID_KEY_F10 0x43
#define HID_KEY_F11 0x44
#define HID_KEY_F12 0x45
#define HID_KEY_PRINT_SCREEN 0x46
#define HID_KEY_SCROLL_LOCK 0x47
#define HID_KEY_PAUSE 0x48
#define HID_KEY_INSERT 0x49
#define HID_KEY_HOME 0x4A
#define HID_KEY_PAGE_UP 0x4B
#define HID_KEY_DELETE 0x4C
#define HID_KEY_END 0x4D
#define HID_KEY_PAGE_DOWN 0x4E
#define HID_KEY_ARROW_RIGHT 0x4F
#define HID_KEY_ARROW_LEFT 0x50
#define HID_KEY_ARROW_DOWN 0x51
#define HID_KEY_ARROW_UP 0x52
#define HID_KEY_NUM_LOCK 0x53
#define HID_KEY_KEYPAD_DIVIDE 0x54
#define HID_KEY_KEYPAD_MULTIPLY 0x55
#define HID_KEY_KEYPAD_SUBTRACT 0x56
#define HID_KEY_KEYPAD_ADD 0x57
#define HID_KEY_KEYPAD_ENTER 0x58
#define HID_KEY_KEYPAD_1 0x59
#define HID_KEY_KEYPAD_2 0x5A
#define HID_KEY_KEYPAD_3 0x5B
#define HID_KEY_KEYPAD_4 0x5C
#define HID_KEY_KEYPAD_5 0x5D
#define HID_KEY_KEYPAD_6 0x5E
#define HID_KEY_KEYPAD_7 0x5F
#define HID_KEY_KEYPAD_8 0x60
#define HID_KEY_KEYPAD_9 0x61
#define HID_KEY_KEYPAD_0 0x62
#define HID_KEY_KEYPAD_DECIMAL 0x63
#define HID_KEY_EUROPE_2 0x64
#define HID_KEY_APPLICATION 0x65
#define HID_KEY_POWER 0x66
#define HID_KEY_KEYPAD_EQUAL 0x67
#define HID_KEY_F13 0x68
#define HID_KEY_F14 0x69
#define HID_KEY_F15 0x6A
#define HID_KEY_F16 0x6B
#define HID_KEY_F17 0x6C
#define HID_KEY_F18 0x6D
#define HID_KEY_F19 0x6E
#define HID_KEY_F20 0x6F
#define HID_KEY_F21 0x70
#define HID_KEY_F22 0x71
#define HID_KEY_F23 0x72
#define HID_KEY_F24 0x73
#define HID_KEY_EXECUTE 0x74
#define HID_KEY_HELP 0x75
#define HID_KEY_MENU 0x76
#define HID_KEY_SELECT 0x77
#define HID_KEY_STOP 0x78
#define HID_KEY_AGAIN 0x79
#define HID_KEY_UNDO 0x7A
#define HID_KEY_CUT 0x7B
#define HID_KEY_COPY 0x7C
#define HID_KEY_PASTE 0x7D
#define HID_KEY_FIND 0x7E
#define HID_KEY_MUTE 0x7F
#define HID_KEY_VOLUME_UP 0x80
#define HID_KEY_VOLUME_DOWN 0x81
#define HID_KEY_LOCKING_CAPS_LOCK 0x82
#define HID_KEY_LOCKING_NUM_LOCK 0x83
#define HID_KEY_LOCKING_SCROLL_LOCK 0x84
#define HID_KEY_KEYPAD_COMMA 0x85
#define HID_KEY_KEYPAD_EQUAL_SIGN 0x86
#define HID_KEY_KANJI1 0x87
#define HID_KEY_KANJI2 0x88
#define HID_KEY_KANJI3 0x89
#define HID_KEY_KANJI4 0x8A
#define HID_KEY_KANJI5 0x8B
#define HID_KEY_KANJI6 0x8C
#define HID_KEY_KANJI7 0x8D
#define HID_KEY_KANJI8 0x8E
#define HID_KEY_KANJI9 0x8F
#define HID_KEY_LANG1 0x90
#define HID_KEY_LANG2 0x91
#define HID_KEY_LANG3 0x92
#define HID_KEY_LANG4 0x93
#define HID_KEY_LANG5 0x94
#define HID_KEY_LANG6 0x95
#define HID_KEY_LANG7 0x96
#define HID_KEY_LANG8 0x97
#define HID_KEY_LANG9 0x98
#define HID_KEY_ALTERNATE_ERASE 0x99
#define HID_KEY_SYSREQ_ATTENTION 0x9A
#define HID_KEY_CANCEL 0x9B
#define HID_KEY_CLEAR 0x9C
#define HID_KEY_PRIOR 0x9D
#define HID_KEY_RETURN 0x9E
#define HID_KEY_SEPARATOR 0x9F
#define HID_KEY_OUT 0xA0
#define HID_KEY_OPER 0xA1
#define HID_KEY_CLEAR_AGAIN 0xA2
#define HID_KEY_CRSEL_PROPS 0xA3
#define HID_KEY_EXSEL 0xA4
// RESERVED 0xA5-DF
#define HID_KEY_CONTROL_LEFT 0xE0
#define HID_KEY_SHIFT_LEFT 0xE1
#define HID_KEY_ALT_LEFT 0xE2
#define HID_KEY_GUI_LEFT 0xE3
#define HID_KEY_CONTROL_RIGHT 0xE4
#define HID_KEY_SHIFT_RIGHT 0xE5
#define HID_KEY_ALT_RIGHT 0xE6
#define HID_KEY_GUI_RIGHT 0xE7