"#if defined(USBCON) " ? How do I use the Arduino USBAPI?

Projects Programming
1

At the beginning of the USBAPI.h file is this:

#ifndef __USBAPI__
#define __USBAPI__

#include <inttypes.h>
#include <avr/pgmspace.h>
#include <avr/eeprom.h>
#include <avr/interrupt.h>
#include <util/delay.h>

typedef unsigned char u8;
typedef unsigned short u16;
typedef unsigned long u32;

#include "Arduino.h"

#if defined(USBCON)

#include "USBDesc.h"
#include "USBCore.h"

//================================================================================
//================================================================================
// USB

class USBDevice_
{
public:
 USBDevice_();
 bool configured();

 void attach();
 void detach(); // Serial port goes down too...
 void poll();
};
extern USBDevice_ USBDevice;

I am trying to create my own USBDevice subclass so I can use the USBAPI functions like, USB_Send as well as the HID functions defined in HID.cpp. But no matter what I do it wont let me call the class USBDevice and I think it's because I need to define USBCON as 'something'... but I have no idea what.

Here is my current .ino but ive tried so many different things to get access to the USBAPI. I also Have my HID report file below.

2

Gotta BUMP... im stumped.

3

I don't know anything about usbapi. Is google broken in your country ? A 2 minute consultation with Dr Google seems to suggest that there are quite a few examples out there.

The code you posted seems to be invalid. There is no #endif matching the #if defined(USBCON)

The exact purpose of that USBCON eludes me.

However, as a general concept, it isn't necessarily necessary to give these #define'd parameters an actual value. Merely adding the statement

#define USBCON

will cause that parameter to be defined, and then the following code will be included. It doesn't actually have to have a "value".

4

I have already tried the adding the obvious #define USBCON to my .ino but to no avail. One of the reasons I was thinking that this function needs to be defined as 'something' is because it isnt the usual #ifdef function... That kind of threw me off even though everything I've read says that the two are basically the same function. THe other reason I think that USBCON needs to be defined as something is because when I trace the definition ('right click' > 'go to definition' via the STINO plugin with simple text 3) it takes me to the file iom16u2.h. Which I have no idea wtf that header is about. And in that header is defined:

#define USBCON _SFR_MEM8(0xD8)
#define FRZCLK 5
#define USBE 7

The other reason I think USBCON needs to be defined as something is because some of the functions that I want to use, which are defined in the USBCore.cpp file, like:

int USB_Send(u8 ep, const void* d, int len)
{
	if (!_usbConfiguration)
		return -1;

	int r = len;
	const u8* data = (const u8*)d;
	u8 timeout = 250;		// 250ms timeout on send? TODO
	while (len)
	{
		u8 n = USB_SendSpace(ep);
		if (n == 0)
		{
			if (!(--timeout))
				return -1;
			delay(1);
			continue;
		}

		if (n > len)
			n = len;
		{
			LockEP lock(ep);
			// Frame may have been released by the SOF interrupt handler
			if (!ReadWriteAllowed())
				continue;
			len -= n;
			if (ep & TRANSFER_ZERO)
			{
				while (n--)
					Send8(0);
			}
			else if (ep & TRANSFER_PGM)
			{
				while (n--)
					Send8(pgm_read_byte(data++));
			}
			else
			{
				while (n--)
					Send8(*data++);
			}
			if (!ReadWriteAllowed() || ((len == 0) && (ep & TRANSFER_RELEASE)))	// Release full buffer
				ReleaseTX();
		}
	}
	TXLED1;					// light the TX LED
	TxLEDPulse = TX_RX_LED_PULSE_MS;
	return r;
}

extern const u8 _initEndpoints[] PROGMEM;
const u8 _initEndpoints[] = 
{
	0,
	
#ifdef CDC_ENABLED
	EP_TYPE_INTERRUPT_IN,		// CDC_ENDPOINT_ACM
	EP_TYPE_BULK_OUT,			// CDC_ENDPOINT_OUT
	EP_TYPE_BULK_IN,			// CDC_ENDPOINT_IN
#endif

#ifdef HID_ENABLED
	EP_TYPE_INTERRUPT_IN		// HID_ENDPOINT_INT
#endif
};

#define EP_SINGLE_64 0x32	// EP0
#define EP_DOUBLE_64 0x36	// Other endpoints

static
void InitEP(u8 index, u8 type, u8 size)
{
	UENUM = index;
	UECONX = 1;
	UECFG0X = type;
	UECFG1X = size;
}

static
void InitEndpoints()
{
	for (u8 i = 1; i < sizeof(_initEndpoints); i++)
	{
		UENUM = i;
		UECONX = 1;
		UECFG0X = pgm_read_byte(_initEndpoints+i);
		UECFG1X = EP_DOUBLE_64;
	}
	UERST = 0x7E;	// And reset them
	UERST = 0;
}

//	Handle CLASS_INTERFACE requests
static
bool ClassInterfaceRequest(Setup& setup)
{
	u8 i = setup.wIndex;

#ifdef CDC_ENABLED
	if (CDC_ACM_INTERFACE == i)
		return CDC_Setup(setup);
#endif

#ifdef HID_ENABLED
	if (HID_INTERFACE == i)
		return HID_Setup(setup);
#endif
	return false;
}

int _cmark;
int _cend;

call and declare variables which are inside that iom16u2.h file, the purpose of which confuses me.

#define UECONX _SFR_MEM8(0xEB)
#define EPEN 0
#define RSTDT 3
#define STALLRQC 4
#define STALLRQ 5

And no google is not broken in my country but as I said I've done my research said im still stumped. Thanks for the snark :-\

5

Also, the #endif is in the USBAPI.h file which I didnt post to github. I will post it now just for convenience of anyone willing to help me.

6

USBCON will be defined in the mcu header file if the mcu has USB hardware. It is a register to configure the USB hardware, the definition is the register address. Without the mcu hardware I doubt the USB API will be of much use.

7

I suggest get started by trying out in the Arduino IDE, under File, Examples, 09.USB there are several sketches which use USB. Then you can build on that.
A typical processor for those programs in Arduino land is the ATmega32U4 which is on board the Arduino Leonardo, Pro Micro, Micro, and a few other models. I have heard trying to implement USB on a processor without native USB hardware is difficult.