Trouble using USBHost library to interface with Logitech Extreme 3D Pro Joystick

Hi everyone,

I am working on a drone project where I’m going to use a joystick to control the drone. I thought the easiest way to do this would be to use a flight joystick and connect that to my Arduino Due native USB port and send data to the drone through radio. I found a library called USBHost ( GitHub - arduino-libraries/USBHost: USB Host Library for Arduino ) and thought that would be perfect. I tested that library’s mouse and keyboard examples and they worked perfectly. I couldnt find any complete code online for any type of joystick that worked so i decided to try and create my own. The USBHost library uses some C++ techniques that i am not familiar with so i tried my best to mimic the format of the mouse and keyboard code. Here is the code that I generated:

JoystickController.cpp

`
#include <JoystickController.h>

extern “C” {
void __joystickControllerEmptyCallback() { }
}

void OnJoystickChanged() attribute ((weak, alias("__joystickControllerEmptyCallback")));

uint8_t JoystickController::getButtons_a() { return buttons_a; }
uint8_t JoystickController::getButtons_b() { return buttons_b; }
uint8_t JoystickController::getSliderValue() { return slider; }
uint32_t JoystickController::getAxesValues() { return axes; }
uint16_t JoystickController::getXValue() { return x; }
uint16_t JoystickController::getYValue() { return y; }
uint8_t JoystickController::getHatValue() { return hat; }
uint8_t JoystickController::getTwistValue() { return twist; }
`

JoystickController.h
`
#ifndef JOYSTICK_CONTROLLER_H
#define JOYSTICK_CONTROLLER_H

#include <hidboot.h>

class JoystickController : public JoystickReportParser
{
public:
JoystickController(USBHost &usb) : hostJoystick(&usb), axes(0) , buttons_a(0), buttons_b(0) , slider(0) {
hostJoystick.SetReportParser(0, this);
};

uint8_t getButtons_a();
uint8_t getButtons_b();
uint8_t getSliderValue();
uint32_t getAxesValues();
uint16_t getXValue();
uint16_t getYValue();
uint8_t getHatValue();
uint8_t getTwistValue();

protected:
virtual void OnJoystickChanged(JOYSTICKINFO *js);

private:
HIDBoot<HID_PROTOCOL_JOYSTICK> hostJoystick;
union { //axes and hat switch
uint32_t axes;
struct {
uint32_t x : 10;
uint32_t y : 10;
uint32_t hat : 4;
uint32_t twist : 8;
};
};
uint8_t buttons_a;
uint8_t buttons_b;
uint8_t slider;

};

#endif
`

I added this to hidboot.cpp

`
void JoystickReportParser::Parse(HID *hid, bool is_rpt_id, uint8_t len, uint8_t *buf)
{
bool match = true;
JOYSTICKINFO pjs = (JOYSTICKINFO)buf;

// Checking if there are changes in report since the method was last called
for (uint8_t i=0; i<7; i++) {
if( buf != prevState.oldPad ) {
* match = false;*
* break;*
* }*
* }*
* // Calling Game Pad event handler*
* if (!match && pjs) {*
_ OnJoystickChanged((JOYSTICKINFO*)buf);_
* //OnJoystickChanged(buf);*

* for (uint8_t i=0; i<7; i++)
prevState.oldPad _= buf;
}
}
*_</em></em> <em><em>_*and i added this to hdiboot.h*_</em></em> <em><em>_*
/**
\brief JOYINFO definition.

/
struct JOYSTICKINFO
{
union { //axes and hat switch*

* uint32_t axes;*
* struct {_
uint32_t x : 10;
uint32_t y : 10;
uint32_t hat : 4;
uint32_t twist : 8;
_ };
};_

uint8_t buttons_a;
uint8_t buttons_b;
uint8_t slider;
_};*_

/**
* \class JoystickReportParser definition.
*/
class JoystickReportParser : public HIDReportParser
{
* union*
* {*
// JoystickEvents *joystickEvents;
* JOYSTICKINFO joystickInfo;*
* uint8_t oldPad[7];
uint8_t oldHat;
uint16_t oldButtons;
_ } prevState;*_

public:
_ //JoystickReportParser(JoystickEvents *evt);_
virtual void Parse(HID *hid, bool is_rpt_id, uint8_t len, uint8_t *buf);

protected:
virtual void OnJoystickChanged(JOYSTICKINFO *js) {};
};
*_</em></em> <em><em>_*And when I tried to impliment this in an arduino sketch, I got the following errors:*_</em></em> <em><em>_*
JoystickController:9: error: cannot declare variable ‘joy’ to be of abstract type ‘JoystickController’
JoystickController joy(usb);
* ^*
In file included from C:\Users\Aaron\Documents\Arduino\JoystickController\JoystickController.ino:3:0:
C:\Users\Aaron\Documents\Arduino\libraries\USBHost\src/JoystickController.h:11:7: note: because the following virtual functions are pure within ‘JoystickController’:
class JoystickController : public JoystickReportParser
* ^*
In file included from C:\Users\Aaron\Documents\Arduino\libraries\USBHost\src/hidboot.h:24:0,
* from C:\Users\Aaron\Documents\Arduino\libraries\USBHost\src/JoystickController.h:7,*
* from C:\Users\Aaron\Documents\Arduino\JoystickController\JoystickController.ino:3:*
C:\Users\Aaron\Documents\Arduino\libraries\USBHost\src/hid.h:157:15: note: virtual void HIDReportParser::Parse(HID*, bool, uint32_t, uint8_t*)
virtual void Parse(HID hid, bool is_rpt_id, uint32_t len, uint8_t buf) = 0;
_ ^

Using library USBHost at version 1.0.4 in folder: C:\Users\Aaron\Documents\Arduino\libraries\USBHost
exit status 1
cannot declare variable ‘joy’ to be of abstract type ‘JoystickController’
`
I searched for any differences in how the mouse and keyboard controllers were initialized and I couldn’t find anything. I’m not very experienced in C++ so i need some help.
Thanks in advance,
Aaron
USBHost.zip (55 KB)_