USBTransmitter with 8 axes and 8 buttons, see https://www.instructables.com/id/RC-Transmitter-to-USB-Gamepad-Using-Arduino/

HIDJoy.cpp

//This Modifed version of VUSB was created in part by Rickey Ward, the USB HID descriptor
//was designed to be generic and useful, feel free to use this code to develop cool
//arduino based gamepads!

#include "HIDJoy.h"

#include <avr/io.h>
#include <avr/wdt.h>
#include <avr/interrupt.h>  /* for sei() */
#include <util/delay.h>     /* for _delay_ms() */
#include <avr/eeprom.h>
#include <avr/pgmspace.h>   /* required by usbdrv.h */
#include "usbdrv.h"

#include <stdio.h>
#include <string.h>
#include <inttypes.h>

static uchar received = 0;
static uchar outBuffer[8];
static uchar inBuffer[HIDSERIAL_INBUFFER_SIZE];
static uchar reportId = 0;
static uchar bytesRemaining;
static uchar* pos;

static gamepad_report_t gameReport;

/*
PROGMEM const char usbHidReportDescriptor[36] = {
0x05, 0x01,                    // USAGE_PAGE (Generic Desktop)
0x09, 0x05,                    // USAGE (Game Pad)
0xa1, 0x01,                    // COLLECTION (Application)
0xa1, 0x00,                    //   COLLECTION (Physical)
0x05, 0x01,                    //     USAGE_PAGE (Generic Desktop)
0x09, 0x30,                    //     USAGE (X)
0x09, 0x31,                    //     USAGE (Y)
0x09, 0x32,                    //     USAGE (Z) rx
0x09, 0x35,                    //     USAGE (Rx) ry
0x35, 0x00,                    //     PHYSICAL_MINIMUM (0)
0x46, 0xff, 0x00,              //     PHYSICAL_MAXIMUM (255)
0x15, 0x00,                    //     LOGICAL_MINIMUM (-127)
0x26, 0xff, 0x00,                    //     LOGICAL_MAXIMUM (127)
0x75, 0x08,                    //     REPORT_SIZE (8)
0x95, 0x04,                    //     REPORT_COUNT (4)
0x81, 0x02,                    //     INPUT (Data,Var,Abs)
0xc0,                          //   END_COLLECTION
0xc0                           // END_COLLECTION
};
*/
PROGMEM const char usbHidReportDescriptor[USB_CFG_HID_REPORT_DESCRIPTOR_LENGTH] = {
0x05, 0x01,                    // USAGE_PAGE (Generic Desktop)
0x09, 0x05,                    // USAGE (Game Pad)
0xa1, 0x01,                    // COLLECTION (Application)
0xa1, 0x00,                    //   COLLECTION (Physical)
0x05, 0x09,                    //     USAGE_PAGE (Button)
0x19, 0x01,                    //     USAGE_MINIMUM (Button 1)
0x29, 0x08,                    //     USAGE_MAXIMUM (Button 8)
0x15, 0x00,                    //     LOGICAL_MINIMUM (0)
0x25, 0x01,                    //     LOGICAL_MAXIMUM (1)
0x95, 0x08,                    //     REPORT_COUNT (8)
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) rx
0x09, 0x33,                    //     USAGE (Rx)
0x09, 0x34,                    //     USAGE (Ry)
0x09, 0x35,                    //     USAGE (Rz)
0x09, 0x36,                    //     USAGE (Slider)
0x09, 0x36,                    //     USAGE (Slider)
0x35, 0x00,                    //     PHYSICAL_MINIMUM (0)
0x46, 0xff, 0x00,              //     PHYSICAL_MAXIMUM (255)
0x15, 0x00,                    //     LOGICAL_MINIMUM (-127)
0x26, 0xff, 0x00,              //     LOGICAL_MAXIMUM (127)
0x75, 0x08,                    //     REPORT_SIZE (8)
0x95, 0x08,                    //     REPORT_COUNT (8)
0x81, 0x02,                    //     INPUT (Data,Var,Abs)
0xc0,                          //   END_COLLECTION
0xc0                           // END_COLLECTION
};
// see also http://eleccelerator.com/tutorial-about-usb-hid-report-descriptors/
// see also https://forum.pjrc.com/threads/23681-Many-axis-joystick/page2

/* usbFunctionRead() is called when the host requests a chunk of data from
 * the device. For more information see the documentation in usbdrv/usbdrv.h.
 */
uchar   usbFunctionRead(uchar *data, uchar len)
{
    return 0;
}

/* usbFunctionWrite() is called when the host sends a chunk of data to the
 * device. For more information see the documentation in usbdrv/usbdrv.h.
 */
uchar   usbFunctionWrite(uchar *data, uchar len)
{
    if (reportId == 0) {
        int i;
        if(len > bytesRemaining)
            len = bytesRemaining;
        bytesRemaining -= len;
        //int start = (pos==inBuffer)?1:0;
        for(i=0;i<len;i++) {
            if (data[i]!=0) {
                *pos++ = data[i];
             }
        }
        if (bytesRemaining == 0) {
            received = 1;
            *pos++ = 0;
            return 1;
        } else {
            return 0;
        }
    } else {
        return 1;
    }
}

usbMsgLen_t usbFunctionSetup(uchar data[8])
{
    usbRequest_t    *rq = (usbRequest_t *)data;
    reportId = rq->wValue.bytes[0];
    if((rq->bmRequestType & USBRQ_TYPE_MASK) == USBRQ_TYPE_CLASS){    /* HID class request */
        if(rq->bRequest == USBRQ_HID_GET_REPORT){
          /* wValue: ReportType (highbyte), ReportID (lowbyte) */
            /* since we have only one report type, we can ignore the report-ID */
            return USB_NO_MSG;  /* use usbFunctionRead() to obtain data */
        }else if(rq->bRequest == USBRQ_HID_SET_REPORT){
            /* since we have only one report type, we can ignore the report-ID */
            pos = inBuffer;
            bytesRemaining = rq->wLength.word;
            if(bytesRemaining > sizeof(inBuffer))
                bytesRemaining = sizeof(inBuffer);
            return USB_NO_MSG;  /* use usbFunctionWrite() to receive data from host */
        }
    }else{
        /* ignore vendor type requests, we don't use any */
    }
    return 0;
}

HIDJoy::HIDJoy()
{

}

void HIDJoy::begin()
{
  uchar i;
  cli();
  usbDeviceDisconnect();
  i = 0;
  while(--i){             /* fake USB disconnect for > 250 ms */
    _delay_ms(1);
  }
  usbDeviceConnect();
  usbInit();
  sei();

  received = 0;
}

void HIDJoy::poll()
{
    usbPoll();
}

uchar HIDJoy::available()
{
    return received;
}

uchar HIDJoy::read(uchar *buffer)
{
    if(received == 0) return 0;
    int i;
    for(i=0;inBuffer[i]!=0&&i<HIDSERIAL_INBUFFER_SIZE;i++)
    {
        buffer[i] = inBuffer[i];
    }
    inBuffer[0] = 0;
    buffer[i] = 0;
    received = 0;
    return i;
}

// write one character

size_t HIDJoy::writeGame(int8_t Lx, int8_t Ly, int8_t Rx, int8_t Ry, int8_t ch5, int8_t ch6, int8_t ch7, int8_t ch8)
{
  while(!usbInterruptIsReady()) {
    usbPoll();
  }

  gameReport.buttons = (Lx<0) | ((Ly<0) << 1) | ((Rx<0) << 2) | ((Ry<0) << 3) |
                       ((ch5<0) << 4) | ((ch6<0) << 5) | ((ch7<0) << 6) | ((ch8<0) << 7);
  gameReport.left_x = Lx;
  gameReport.left_y = Ly;
  gameReport.right_x = Rx;
  gameReport.right_y = Ry;
  gameReport.ch5 = ch5;
  gameReport.ch6 = ch6;
  gameReport.ch7 = ch7;
  gameReport.ch8 = ch8;

//  usbSetInterrupt((unsigned char *)&gameReport, sizeof(gamepad_report_t));  // write max 8 bytes
  write((uint8_t *)&gameReport, sizeof(gamepad_report_t));  // write more than 8 bytes
  return 1;
}


size_t HIDJoy::write(uint8_t data)
{
  while(!usbInterruptIsReady()) {
    usbPoll();
  }
  memset(outBuffer, 0, 8);
  outBuffer[0] = data;
  usbSetInterrupt(outBuffer, 8);
  return 1;
}

// You should be able to simulate a 16 byte interrupt transfer with the following procedure:
//   * Pass the first 8 bytes with usbSetInterrupt().
//   * Wait until they are transferred with usbInterruptIsReady().
//   * Pass the next 8 bytes with usbSetInterrupt().
//   * Wait until the transaction is complete with usbInterruptIsReady().
//   * Call usbSetInterrupt() with 0 bytes to indicate the end of transfer.
// If your payload is only 15 bytes, you save the last 0 byte transaction. The end of transfer is indicated by a transaction with less than 8 bytes.
// see also https://forums.obdev.at/viewtopic.php?p=330&sid=a371f0d9c43f177db4b8f5987f0e5fb2#p330

// write up to 8 characters
size_t HIDJoy::write8(const uint8_t *buffer, size_t size)
{
  unsigned char i;
  while(!usbInterruptIsReady()) {
    usbPoll();
  }
  memset(outBuffer, 0, 8);
  for(i=0;i<size && i<8; i++) {
    outBuffer[i] = buffer[i];
  }
//  usbSetInterrupt(outBuffer, 8);
  usbSetInterrupt(outBuffer, (size<8) ? size : 8);
  return (i);
}

// write a string
size_t HIDJoy::write(const uint8_t *buffer, size_t size)
{
  size_t count = 0;
  unsigned char i;
  for(i=0; i< (size/8) + 1; i++) {
    count += write8(buffer+i*8, (size<(count+8)) ? (size-count) : 8);
  }
// also need to call usbSetInterrupt() with 0 bytes to indicate the end of transfer
// if size is a multiple of 8 (8 excluded; 16, 24, 32, ...)
  return count;
}

HIDJoy.h

#ifndef HIDJoy_h
#define HIDJoy_h

#include "Arduino.h"
#include "Print.h"

#define HIDSERIAL_INBUFFER_SIZE 32


struct gamepad_report_t
{
  uint8_t buttons;
  int8_t left_x;
  int8_t left_y;
  int8_t right_x;
  int8_t right_y;
  int8_t ch5;
  int8_t ch6;
  int8_t ch7;
  int8_t ch8;
};  // size: 9 bytes

class HIDJoy : public Print {
public:
  HIDJoy();
  size_t write(uint8_t);  // write one character
  size_t write(const uint8_t *buffer, size_t size); // write a string

  size_t writeGame(int8_t Lx, int8_t Ly, int8_t Rx, int8_t Ry, int8_t ch5, int8_t ch6, int8_t ch7, int8_t ch8);

  static void poll();
  static unsigned char available();
  static unsigned char read(unsigned char *buffer);
  static void begin();
  struct name_t {
    /* data */
  };


private:
  size_t write8(const uint8_t *buffer, size_t size);  // write up to 8 characters
};

#endif

usbconfig.h

/* Name: usbconfig.h
 * Project: V-USB, virtual USB port for Atmel's(r) AVR(r) microcontrollers
 * Author: Christian Starkjohann
 * Creation Date: 2005-04-01
 * Tabsize: 4
 * Copyright: (c) 2005 by OBJECTIVE DEVELOPMENT Software GmbH
 * License: GNU GPL v2 (see License.txt), GNU GPL v3 or proprietary (CommercialLicense.txt)
 */

#ifndef __usbconfig_h_included__
#define __usbconfig_h_included__

/*
General Description:
This file is an example configuration (with inline documentation) for the USB
driver. It configures V-USB for USB D+ connected to Port D bit 2 (which is
also hardware interrupt 0 on many devices) and USB D- to Port D bit 4. You may
wire the lines to any other port, as long as D+ is also wired to INT0 (or any
other hardware interrupt, as long as it is the highest level interrupt, see
section at the end of this file).
*/

/* ---------------------------- Hardware Config ---------------------------- */

#define USB_CFG_IOPORTNAME      D
/* This is the port where the USB bus is connected. When you configure it to
 * "B", the registers PORTB, PINB and DDRB will be used.
 */
#define USB_CFG_DMINUS_BIT      7
/* This is the bit number in USB_CFG_IOPORT where the USB D- line is connected.
 * This may be any bit in the port.
 */
#define USB_CFG_DPLUS_BIT       2
/* This is the bit number in USB_CFG_IOPORT where the USB D+ line is connected.
 * This may be any bit in the port. Please note that D+ must also be connected
 * to interrupt pin INT0! [You can also use other interrupts, see section
 * "Optional MCU Description" below, or you can connect D- to the interrupt, as
 * it is required if you use the USB_COUNT_SOF feature. If you use D- for the
 * interrupt, the USB interrupt will also be triggered at Start-Of-Frame
 * markers every millisecond.]
 */
#define USB_CFG_CLOCK_KHZ       (F_CPU/1000)
/* Clock rate of the AVR in kHz. Legal values are 12000, 12800, 15000, 16000,
 * 16500, 18000 and 20000. The 12.8 MHz and 16.5 MHz versions of the code
 * require no crystal, they tolerate +/- 1% deviation from the nominal
 * frequency. All other rates require a precision of 2000 ppm and thus a
 * crystal!
 * Since F_CPU should be defined to your actual clock rate anyway, you should
 * not need to modify this setting.
 */
#define USB_CFG_CHECK_CRC       0
/* Define this to 1 if you want that the driver checks integrity of incoming
 * data packets (CRC checks). CRC checks cost quite a bit of code size and are
 * currently only available for 18 MHz crystal clock. You must choose
 * USB_CFG_CLOCK_KHZ = 18000 if you enable this option.
 */

/* ----------------------- Optional Hardware Config ------------------------ */

/* #define USB_CFG_PULLUP_IOPORTNAME   D */
/* If you connect the 1.5k pullup resistor from D- to a port pin instead of
 * V+, you can connect and disconnect the device from firmware by calling
 * the macros usbDeviceConnect() and usbDeviceDisconnect() (see usbdrv.h).
 * This constant defines the port on which the pullup resistor is connected.
 */
/* #define USB_CFG_PULLUP_BIT          4 */
/* This constant defines the bit number in USB_CFG_PULLUP_IOPORT (defined
 * above) where the 1.5k pullup resistor is connected. See description
 * above for details.
 */

/* --------------------------- Functional Range ---------------------------- */

#define USB_CFG_HAVE_INTRIN_ENDPOINT    1
/* Define this to 1 if you want to compile a version with two endpoints: The
 * default control endpoint 0 and an interrupt-in endpoint (any other endpoint
 * number).
 */
#define USB_CFG_HAVE_INTRIN_ENDPOINT3   0
/* Define this to 1 if you want to compile a version with three endpoints: The
 * default control endpoint 0, an interrupt-in endpoint 3 (or the number
 * configured below) and a catch-all default interrupt-in endpoint as above.
 * You must also define USB_CFG_HAVE_INTRIN_ENDPOINT to 1 for this feature.
 */
#define USB_CFG_EP3_NUMBER              3
/* If the so-called endpoint 3 is used, it can now be configured to any other
 * endpoint number (except 0) with this macro. Default if undefined is 3.
 */
/* #define USB_INITIAL_DATATOKEN           USBPID_DATA1 */
/* The above macro defines the startup condition for data toggling on the
 * interrupt/bulk endpoints 1 and 3. Defaults to USBPID_DATA1.
 * Since the token is toggled BEFORE sending any data, the first packet is
 * sent with the oposite value of this configuration!
 */
#define USB_CFG_IMPLEMENT_HALT          0
/* Define this to 1 if you also want to implement the ENDPOINT_HALT feature
 * for endpoint 1 (interrupt endpoint). Although you may not need this feature,
 * it is required by the standard. We have made it a config option because it
 * bloats the code considerably.
 */
#define USB_CFG_SUPPRESS_INTR_CODE      0
/* Define this to 1 if you want to declare interrupt-in endpoints, but don't
 * want to send any data over them. If this macro is defined to 1, functions
 * usbSetInterrupt() and usbSetInterrupt3() are omitted. This is useful if
 * you need the interrupt-in endpoints in order to comply to an interface
 * (e.g. HID), but never want to send any data. This option saves a couple
 * of bytes in flash memory and the transmit buffers in RAM.
 */
#define USB_CFG_INTR_POLL_INTERVAL      100
/* If you compile a version with endpoint 1 (interrupt-in), this is the poll
 * interval. The value is in milliseconds and must not be less than 10 ms for
 * low speed devices.
 */
#define USB_CFG_IS_SELF_POWERED         0
/* Define this to 1 if the device has its own power supply. Set it to 0 if the
 * device is powered from the USB bus.
 */
#define USB_CFG_MAX_BUS_POWER           250
/* Set this variable to the maximum USB bus power consumption of your device.
 * The value is in milliamperes. [It will be divided by two since USB
 * communicates power requirements in units of 2 mA.]
 */
#define USB_CFG_IMPLEMENT_FN_WRITE      1
/* Set this to 1 if you want usbFunctionWrite() to be called for control-out
 * transfers. Set it to 0 if you don't need it and want to save a couple of
 * bytes.
 */
#define USB_CFG_IMPLEMENT_FN_READ       1
/* Set this to 1 if you need to send control replies which are generated
 * "on the fly" when usbFunctionRead() is called. If you only want to send
 * data from a static buffer, set it to 0 and return the data from
 * usbFunctionSetup(). This saves a couple of bytes.
 */
#define USB_CFG_IMPLEMENT_FN_WRITEOUT   0
/* Define this to 1 if you want to use interrupt-out (or bulk out) endpoints.
 * You must implement the function usbFunctionWriteOut() which receives all
 * interrupt/bulk data sent to any endpoint other than 0. The endpoint number
 * can be found in 'usbRxToken'.
 */
#define USB_CFG_HAVE_FLOWCONTROL        0
/* Define this to 1 if you want flowcontrol over USB data. See the definition
 * of the macros usbDisableAllRequests() and usbEnableAllRequests() in
 * usbdrv.h.
 */
#define USB_CFG_DRIVER_FLASH_PAGE       0
/* If the device has more than 64 kBytes of flash, define this to the 64 k page
 * where the driver's constants (descriptors) are located. Or in other words:
 * Define this to 1 for boot loaders on the ATMega128.
 */
#define USB_CFG_LONG_TRANSFERS          0
/* Define this to 1 if you want to send/receive blocks of more than 254 bytes
 * in a single control-in or control-out transfer. Note that the capability
 * for long transfers increases the driver size.
 */
/* #define USB_RX_USER_HOOK(data, len)     if(usbRxToken == (uchar)USBPID_SETUP) blinkLED(); */
/* This macro is a hook if you want to do unconventional things. If it is
 * defined, it's inserted at the beginning of received message processing.
 * If you eat the received message and don't want default processing to
 * proceed, do a return after doing your things. One possible application
 * (besides debugging) is to flash a status LED on each packet.
 */
/* #define USB_RESET_HOOK(resetStarts)     if(!resetStarts){hadUsbReset();} */
/* This macro is a hook if you need to know when an USB RESET occurs. It has
 * one parameter which distinguishes between the start of RESET state and its
 * end.
 */
/* #define USB_SET_ADDRESS_HOOK()              hadAddressAssigned(); */
/* This macro (if defined) is executed when a USB SET_ADDRESS request was
 * received.
 */
#define USB_COUNT_SOF                   0
/* define this macro to 1 if you need the global variable "usbSofCount" which
 * counts SOF packets. This feature requires that the hardware interrupt is
 * connected to D- instead of D+.
 */
/* #ifdef __ASSEMBLER__
 * macro myAssemblerMacro
 *     in      YL, TCNT0
 *     sts     timer0Snapshot, YL
 *     endm
 * #endif
 * #define USB_SOF_HOOK                    myAssemblerMacro
 * This macro (if defined) is executed in the assembler module when a
 * Start Of Frame condition is detected. It is recommended to define it to
 * the name of an assembler macro which is defined here as well so that more
 * than one assembler instruction can be used. The macro may use the register
 * YL and modify SREG. If it lasts longer than a couple of cycles, USB messages
 * immediately after an SOF pulse may be lost and must be retried by the host.
 * What can you do with this hook? Since the SOF signal occurs exactly every
 * 1 ms (unless the host is in sleep mode), you can use it to tune OSCCAL in
 * designs running on the internal RC oscillator.
 * Please note that Start Of Frame detection works only if D- is wired to the
 * interrupt, not D+. THIS IS DIFFERENT THAN MOST EXAMPLES!
 */
#define USB_CFG_CHECK_DATA_TOGGLING     0
/* define this macro to 1 if you want to filter out duplicate data packets
 * sent by the host. Duplicates occur only as a consequence of communication
 * errors, when the host does not receive an ACK. Please note that you need to
 * implement the filtering yourself in usbFunctionWriteOut() and
 * usbFunctionWrite(). Use the global usbCurrentDataToken and a static variable
 * for each control- and out-endpoint to check for duplicate packets.
 */
#define USB_CFG_HAVE_MEASURE_FRAME_LENGTH   0
/* define this macro to 1 if you want the function usbMeasureFrameLength()
 * compiled in. This function can be used to calibrate the AVR's RC oscillator.
 */
#define USB_USE_FAST_CRC                0
/* The assembler module has two implementations for the CRC algorithm. One is
 * faster, the other is smaller. This CRC routine is only used for transmitted
 * messages where timing is not critical. The faster routine needs 31 cycles
 * per byte while the smaller one needs 61 to 69 cycles. The faster routine
 * may be worth the 32 bytes bigger code size if you transmit lots of data and
 * run the AVR close to its limit.
 */

/* -------------------------- Device Description --------------------------- */

//#define  USB_CFG_VENDOR_ID       0xc0, 0x16 /* = 0x16c0 = 5824 = voti.nl */
#define  USB_CFG_VENDOR_ID       0xdc, 0x27
/* USB vendor ID for the device, low byte first. If you have registered your
 * own Vendor ID, define it here. Otherwise you may use one of obdev's free
 * shared VID/PID pairs. Be sure to read USB-IDs-for-free.txt for rules!
 * *** IMPORTANT NOTE ***
 * This template uses obdev's shared VID/PID pair for Vendor Class devices
 * with libusb: 0x16c0/0x5dc.  Use this VID/PID pair ONLY if you understand
 * the implications!
 */
#define  USB_CFG_DEVICE_ID       0xdf, 0x05 /* obdev's shared PID for HIDs */
/* This is the ID of the product, low byte first. It is interpreted in the
 * scope of the vendor ID. If you have registered your own VID with usb.org
 * or if you have licensed a PID from somebody else, define it here. Otherwise
 * you may use one of obdev's free shared VID/PID pairs. See the file
 * USB-IDs-for-free.txt for details!
 * *** IMPORTANT NOTE ***
 * This template uses obdev's shared VID/PID pair for Vendor Class devices
 * with libusb: 0x16c0/0x5dc.  Use this VID/PID pair ONLY if you understand
 * the implications!
 */
#define USB_CFG_DEVICE_VERSION  0x00, 0x01
/* Version number of the device: Minor number first, then major number.
 */
#define USB_CFG_VENDOR_NAME     'D', 'i', 'a', 'm', 'o', 'n', 'd', 'D', 'r', 'a', 'k', 'e'
#define USB_CFG_VENDOR_NAME_LEN 12
/* These two values define the vendor name returned by the USB device. The name
 * must be given as a list of characters under single quotes. The characters
 * are interpreted as Unicode (UTF-16) entities.
 * If you don't want a vendor name string, undefine these macros.
 * ALWAYS define a vendor name containing your Internet domain name if you use
 * obdev's free shared VID/PID pair. See the file USB-IDs-for-free.txt for
 * details.
 */
 #define USB_CFG_DEVICE_NAME     'T', 'w', 'i', 'n', ' ', 'U', 'S', 'B', ' ', 'J', 'o', 'y', 's', 't', 'i', 'c', 'k'
 #define USB_CFG_DEVICE_NAME_LEN 17
//#define USB_CFG_DEVICE_NAME     'U', 'S', 'B', ' ', 'G', 'a', 'm', 'e', 'p', 'a', 'd'
//#define USB_CFG_DEVICE_NAME_LEN 11
/* Same as above for the device name. If you don't want a device name, undefine
 * the macros. See the file USB-IDs-for-free.txt before you assign a name if
 * you use a shared VID/PID.
 */
/*#define USB_CFG_SERIAL_NUMBER   'N', 'o', 'n', 'e' */
/*#define USB_CFG_SERIAL_NUMBER_LEN   0 */
/* Same as above for the serial number. If you don't want a serial number,
 * undefine the macros.
 * It may be useful to provide the serial number through other means than at
 * compile time. See the section about descriptor properties below for how
 * to fine tune control over USB descriptors such as the string descriptor
 * for the serial number.
 */
#define USB_CFG_DEVICE_CLASS        0
#define USB_CFG_DEVICE_SUBCLASS     0
/* See USB specification if you want to conform to an existing device class.
 * Class 0xff is "vendor specific".
 */
#define USB_CFG_INTERFACE_CLASS     3
#define USB_CFG_INTERFACE_SUBCLASS  0
#define USB_CFG_INTERFACE_PROTOCOL  0
/* See USB specification if you want to conform to an existing device class or
 * protocol. The following classes must be set at interface level:
 * HID class is 3, no subclass and protocol required (but may be useful!)
 * CDC class is 2, use subclass 2 and protocol 1 for ACM
 */

 //was 29 VVVV

//#define USB_CFG_HID_REPORT_DESCRIPTOR_LENGTH    36
#define USB_CFG_HID_REPORT_DESCRIPTOR_LENGTH    60
/* Define this to the length of the HID report descriptor, if you implement
 * an HID device. Otherwise don't define it or define it to 0.
 * If you use this define, you must add a PROGMEM character array named
 * "usbHidReportDescriptor" to your code which contains the report descriptor.
 * Don't forget to keep the array and this define in sync!
 */

/* #define USB_PUBLIC static */
/* Use the define above if you #include usbdrv.c instead of linking against it.
 * This technique saves a couple of bytes in flash memory.
 */

/* ------------------- Fine Control over USB Descriptors ------------------- */
/* If you don't want to use the driver's default USB descriptors, you can
 * provide our own. These can be provided as (1) fixed length static data in
 * flash memory, (2) fixed length static data in RAM or (3) dynamically at
 * runtime in the function usbFunctionDescriptor(). See usbdrv.h for more
 * information about this function.
 * Descriptor handling is configured through the descriptor's properties. If
 * no properties are defined or if they are 0, the default descriptor is used.
 * Possible properties are:
 *   + USB_PROP_IS_DYNAMIC: The data for the descriptor should be fetched
 *     at runtime via usbFunctionDescriptor(). If the usbMsgPtr mechanism is
 *     used, the data is in FLASH by default. Add property USB_PROP_IS_RAM if
 *     you want RAM pointers.
 *   + USB_PROP_IS_RAM: The data returned by usbFunctionDescriptor() or found
 *     in static memory is in RAM, not in flash memory.
 *   + USB_PROP_LENGTH(len): If the data is in static memory (RAM or flash),
 *     the driver must know the descriptor's length. The descriptor itself is
 *     found at the address of a well known identifier (see below).
 * List of static descriptor names (must be declared PROGMEM if in flash):
 *   char usbDescriptorDevice[];
 *   char usbDescriptorConfiguration[];
 *   char usbDescriptorHidReport[];
 *   char usbDescriptorString0[];
 *   int usbDescriptorStringVendor[];
 *   int usbDescriptorStringDevice[];
 *   int usbDescriptorStringSerialNumber[];
 * Other descriptors can't be provided statically, they must be provided
 * dynamically at runtime.
 *
 * Descriptor properties are or-ed or added together, e.g.:
 * #define USB_CFG_DESCR_PROPS_DEVICE   (USB_PROP_IS_RAM | USB_PROP_LENGTH(18))
 *
 * The following descriptors are defined:
 *   USB_CFG_DESCR_PROPS_DEVICE
 *   USB_CFG_DESCR_PROPS_CONFIGURATION
 *   USB_CFG_DESCR_PROPS_STRINGS
 *   USB_CFG_DESCR_PROPS_STRING_0
 *   USB_CFG_DESCR_PROPS_STRING_VENDOR
 *   USB_CFG_DESCR_PROPS_STRING_PRODUCT
 *   USB_CFG_DESCR_PROPS_STRING_SERIAL_NUMBER
 *   USB_CFG_DESCR_PROPS_HID
 *   USB_CFG_DESCR_PROPS_HID_REPORT
 *   USB_CFG_DESCR_PROPS_UNKNOWN (for all descriptors not handled by the driver)
 *
 * Note about string descriptors: String descriptors are not just strings, they
 * are Unicode strings prefixed with a 2 byte header. Example:
 * int  serialNumberDescriptor[] = {
 *     USB_STRING_DESCRIPTOR_HEADER(6),
 *     'S', 'e', 'r', 'i', 'a', 'l'
 * };
 */

#define USB_CFG_DESCR_PROPS_DEVICE                  0
#define USB_CFG_DESCR_PROPS_CONFIGURATION           0
#define USB_CFG_DESCR_PROPS_STRINGS                 0
#define USB_CFG_DESCR_PROPS_STRING_0                0
#define USB_CFG_DESCR_PROPS_STRING_VENDOR           0
#define USB_CFG_DESCR_PROPS_STRING_PRODUCT          0
#define USB_CFG_DESCR_PROPS_STRING_SERIAL_NUMBER    0
#define USB_CFG_DESCR_PROPS_HID                     0
#define USB_CFG_DESCR_PROPS_HID_REPORT              0
#define USB_CFG_DESCR_PROPS_UNKNOWN                 0


#define usbMsgPtr_t unsigned short
/* If usbMsgPtr_t is not defined, it defaults to 'uchar *'. We define it to
 * a scalar type here because gcc generates slightly shorter code for scalar
 * arithmetics than for pointer arithmetics. Remove this define for backward
 * type compatibility or define it to an 8 bit type if you use data in RAM only
 * and all RAM is below 256 bytes (tiny memory model in IAR CC).
 */

/* ----------------------- Optional MCU Description ------------------------ */

/* The following configurations have working defaults in usbdrv.h. You
 * usually don't need to set them explicitly. Only if you want to run
 * the driver on a device which is not yet supported or with a compiler
 * which is not fully supported (such as IAR C) or if you use a differnt
 * interrupt than INT0, you may have to define some of these.
 */
/* #define USB_INTR_CFG            MCUCR */
/* #define USB_INTR_CFG_SET        ((1 << ISC00) | (1 << ISC01)) */
/* #define USB_INTR_CFG_CLR        0 */
/* #define USB_INTR_ENABLE         GIMSK */
/* #define USB_INTR_ENABLE_BIT     INT0 */
/* #define USB_INTR_PENDING        GIFR */
/* #define USB_INTR_PENDING_BIT    INTF0 */
/* #define USB_INTR_VECTOR         INT0_vect */

#endif /* __usbconfig_h_included__ */

USBtx.ino

// *******************************
// USBtx by Rickey Ward
//
// Gamepad with Left and Right
// analog axis - converterd from 
// spektrum flight transmitter
//
// Ex version with calibration mode
//
// ******************************

//include VUSB Library
#include <HIDJoy.h>
//include RcTrainer library
//important! this include must come AFTER HIDJoy.h
#include <RcTrainer.h>


//Create instance of HIDJoystick
HIDJoy joy;
//Create instance of RcTrainer object
RcTrainer tx(1);

//-----------------Vars--------------------------
//vars to hold used configuration, preintialized to Spektrum DX6

//axis lows (top left)
int lxul = 1900;
int lyul = 1900;
int rxul = 1105;
int ryul = 1900;

//adis highs (bottom right)
int lxuh = 1105;
int lyuh = 1105;
int rxuh = 1900;
int ryuh = 1105;


void setup() {
  //start USB communication
  joy.begin();
}

void loop()
{
    //do usb stuff, important to be called often.
    joy.poll();

    //grab data, send it to usb
     
    uint8_t lx = tx.getChannel(3, lxul, lxuh, 0, 255);
    uint8_t ly = tx.getChannel(0, lyul, lyuh, 0, 255);
    uint8_t rx = tx.getChannel(2, rxul, rxuh, 0, 255);
    uint8_t ry = tx.getChannel(1, ryul, ryuh, 0, 255);
    uint8_t ch5 = tx.getChannel(4, 1105, 1900, 0, 255);
    uint8_t ch6 = tx.getChannel(5, 1105, 1900, 0, 255);
    uint8_t ch7 = tx.getChannel(6, 1105, 1900, 0, 255);
    uint8_t ch8 = tx.getChannel(7, 1105, 1900, 0, 255);
    
    joy.writeGame(lx,ly,rx,ry,ch5,ch6,ch7,ch8);
      
  
}//end loop