RE: HID Joystick

StephaneAG — Mon, 17 Sep 2018 21:43:24 GMT

Hi there !

I think the following could be quite useful to you ;)

I couldn't get it to work as intended ( using "Espruino" 's bluetooth stack ), but it works fine as USB HID GamePad

To use it as you wish, take the report descriptor stuff & use that as device, then write to that using Nordic's API wrapper ( I guess - I don't know enough yet on Nordic's neat chip: gotta digg deeper .. )

/* Copyright (c) 2018 Stephane Adam Garnier ( StephaneAG ) - SeedsDesign. See the file LICENSE for copying permission.
    == Espruino GamePad v0.1a ==
    R: this module is in huge wip ( it 'll soon include a wrapper to ease pressing/releasing btns & moving joysticks .. )
*/
/*
Usage:
  var gamepad = require("ble_hid_gamepad");
  NRF.setServices(undefined, { hid : gamepad.report });
  gamepad.sendGamepadState(0b1111111111111111, 127, -127, 127, -127);
*/
// http://www.usb.org/developers/hidpage/Hut1_12v2.pdf
exports.report = new Uint8Array([
  0x05,   0x01,                    // USAGE_PAGE (Generic Desktop)
  0x09,   0x05,                    // USAGE (Game Pad) - Hut1_12v2.pdf p28 of 128
  0xA1,   0x01,                    // COLLECTION (Application)

  0xA1,   0x00,                    //   COLLECTION (Physical)
  0x05,   0x09,                    //     USAGE_PAGE (Button)
  0x19,   0x01,                    //     USAGE_MINIMUM (Button 1)
  0x29,   0x10,                    //     USAGE_MAXIMUM (Button 16)

  0x15,   0x00,                    //     LOGICAL_MINIMUM (0)
  0x25,   0x01,                    //     LOGICAL_MAXIMUM (1)
  0x95,   0x10,                    //     REPORT_COUNT (16)
  0x75,   0x01,                    //     REPORT_SIZE (1)

  0x81,   0x02,                    //     INPUT (Data,Var,Abs)

  0x05,   0x01,                    //     USAGE_PAGE (Generic Desktop)
  0x09,   0x30,                    //     USAGE (X)
  0x09,   0x31,                    //     USAGE (Y)
  0x09,   0x32,                    //     USAGE (Z) - Hut1_12v2.pdf p26 = represents R X-axis
  0x09,   0x33,                    //     USAGE (Rx) - Hut1_12v2.pdf p26 = represents R Y-axis

  0x15,   0x81,                    //     LOGICAL_MINIMUM (-127)
  0x25,   0x7F,                    //     LOGICAL_MAXIMUM (127)
  0x75,   0x08,                    //     REPORT_SIZE (8)
  0x95,   0x04,                    //     REPORT_COUNT (4)

  0x81,   0x06,                    //     INPUT (Data,Var,Abs) - absolute for joysticks ( != rel for mouse )
  0xC0,                            //   END_COLLECTION

  0xc0 ]                           // END_COLLECTION
);

exports.sendGamepadState = function(btnState, x1, y1, x2, y2, cb){
  NRF.sendHIDReport([
    //0x06,                 // bLength
    //0x01,                 // bDescriptorType - constant ( String assigned by USB )
    btnState & 0xFF,      // Byte0
    (btnState>>8) & 0xFF, // Byte1
    x1,                   // Byte2
    y1,                   // Byte3
    x2,                   // Byte4
    y2,                   // Byte5
  ]);
  if (cb) cb();
};

If you get it working, please come back with the right code so that I can issue a commit for the Espruino community :))

This being said & as an "aside quest", I'm currently diggin deeper on how to implement an Xbox360 controller using either ATmega/STMF32/NRF51822: this doesn't use HID but "X-INPUT" instead ( so I guess a whole lotta mess for modding stuff ? .. )

Hoping the above 'll help, keep up the good work ! +

RE: HID Joystick

Ole Bauck — Fri, 16 Sep 2016 10:54:17 GMT

I have not developed a bluetooth hid joystick and do not know of any code available that works with the nRF5x SDK.

I would start with the keyboard or mouse example. First change the report_map_data in hids_init. You can use the array defined here (nRF8001 example code). Then you need to make your own send function for sending joystick data notifications and you should be ready to go.