USB HID Support on Pico!

I've finally managed to add USB HID support on the Pico. An experimental binary for it should be here in an hour or two.

It's taken most of last and this week to work my way around ST's USB drivers, and they now don't bare much relation to the originals at all :(

So... How do you use it?

// Simple mouse
E.setUSBHID({
  reportDescriptor : [
  0x05,   0x01,
  0x09,   0x02,
  0xA1,   0x01,
  0x09,   0x01,

  0xA1,   0x00,
  0x05,   0x09,
  0x19,   0x01,
  0x29,   0x03,

  0x15,   0x00,
  0x25,   0x01,
  0x95,   0x03,
  0x75,   0x01,

  0x81,   0x02,
  0x95,   0x01,
  0x75,   0x05,
  0x81,   0x01,

  0x05,   0x01,
  0x09,   0x30,
  0x09,   0x31,
  0x09,   0x38,

  0x15,   0x81,
  0x25,   0x7F,
  0x75,   0x08,
  0x95,   0x03,

  0x81,   0x06,
  0xC0,   0x09,
  0x3c,   0x05,
  0xff,   0x09,

  0x01,   0x15,
  0x00,   0x25,
  0x01,   0x75,
  0x01,   0x95,

  0x02,   0xb1,
  0x22,   0x75,
  0x06,   0x95,
  0x01,   0xb1,

  0x01,   0xc0 ]
});

function mouse(x,y,b) {
  E.sendUSBHID([b&7,x,y,0]);
}

// Now save, unplug USB and re-plug it

mouse(20,20,0); // moves mouse diagonally down

// Simple Keyboard

E.setUSBHID({
  reportDescriptor : [
        0x05, 0x01,          // Usage Page (Generic Desktop),
        0x09, 0x06,          // Usage (Keyboard),
        0xA1, 0x01,          // Collection (Application),
        0x75, 0x01,          //   Report Size (1),
        0x95, 0x08,          //   Report Count (8),
        0x05, 0x07,          //   Usage Page (Key Codes),
        0x19, 0xE0,          //   Usage Minimum (224),
        0x29, 0xE7,          //   Usage Maximum (231),
        0x15, 0x00,          //   Logical Minimum (0),
        0x25, 0x01,          //   Logical Maximum (1),
        0x81, 0x02,          //   Input (Data, Variable, Absolute), ;Modifier byte
        0x95, 0x01,          //   Report Count (1),
        0x75, 0x08,          //   Report Size (8),
        0x81, 0x03,          //   Input (Constant),                 ;Reserved byte
        0x95, 0x05,          //   Report Count (5),
        0x75, 0x01,          //   Report Size (1),
        0x05, 0x08,          //   Usage Page (LEDs),
        0x19, 0x01,          //   Usage Minimum (1),
        0x29, 0x05,          //   Usage Maximum (5),
        0x91, 0x02,          //   Output (Data, Variable, Absolute), ;LED report
        0x95, 0x01,          //   Report Count (1),
        0x75, 0x03,          //   Report Size (3),
        0x91, 0x03,          //   Output (Constant),                 ;LED report padding
        0x95, 0x06,          //   Report Count (6),
        0x75, 0x08,          //   Report Size (8),
        0x15, 0x00,          //   Logical Minimum (0),
        0x25, 0x68,          //   Logical Maximum(104),
        0x05, 0x07,          //   Usage Page (Key Codes),
        0x19, 0x00,          //   Usage Minimum (0),
        0x29, 0x68,          //   Usage Maximum (104),
        0x81, 0x00,          //   Input (Data, Array),
        0xc0                 // End Collection
  ]
});

  // 1 = modifiers
  // 2 = ?
  // 3..8 = key codes currently down

var KEY = {
  A           : 4 ,
  B           : 5 ,
  C           : 6 ,
  D           : 7 ,
  E           : 8 ,
  F           : 9 ,
  G           : 10,
  H           : 11,
  I           : 12,
  J           : 13,
  K           : 14,
  L           : 15,
  M           : 16,
  N           : 17,
  O           : 18,
  P           : 19,
  Q           : 20,
  R           : 21,
  S           : 22,
  T           : 23,
  U           : 24,
  V           : 25,
  W           : 26,
  X           : 27,
  Y           : 28,
  Z           : 29
};

function tap(key) {
  E.sendUSBHID([0,0,key,0,0,0,0,0]);
  setTimeout(function() { E.sendUSBHID([0,0,0,0,0,0,0,0]); }, 10);
}

function type(txt, callback) {
  if (!txt.length) return;
  var int = setInterval(function() {
    tap(KEY[txt[0]]);
    txt = txt.substr(1);
    if (!txt.length) clearInterval(int);
  }, 20);
}

// Now save, unplug USB and re-plug it

type("HELLOWORLD");

I'll make these all into libraries when it's ready for a proper release, but it's quite usable even now :)