usb_joystick.c

/* Teensyduino Core Library
 * http://www.pjrc.com/teensy/
 * Copyright (c) 2013 PJRC.COM, LLC.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * 1. The above copyright notice and this permission notice shall be 
 * included in all copies or substantial portions of the Software.
 *
 * 2. If the Software is incorporated into a build system that allows 
 * selection among a list of target devices, then similar target
 * devices manufactured by PJRC.COM must be included in the list of
 * target devices and selectable in the same manner.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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 */

#include "usb_dev.h"
#include "usb_joystick.h"
#include "core_pins.h" // for yield()
#include "HardwareSerial.h"
#include <string.h> // for memcpy()

#ifdef JOYSTICK_INTERFACE // defined by usb_dev.h -> usb_desc.h


uint32_t usb_joystick_data[3];


// Maximum number of transmit packets to queue so we don't starve other endpoints for memory
#define TX_PACKET_LIMIT 3

static uint8_t transmit_previous_timeout=0;

// When the PC isn't listening, how long do we wait before discarding data?
#define TX_TIMEOUT_MSEC 30

#if F_CPU == 96000000
  #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 596)
#elif F_CPU == 48000000
  #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 428)
#elif F_CPU == 24000000
  #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 262)
#endif




int usb_joystick_send(void)
{
        uint32_t wait_count=0;
        usb_packet_t *tx_packet;

	//serial_print("send");
	//serial_print("\n");
        while (1) {
                if (!usb_configuration) {
			//serial_print("error1\n");
                        return -1;
                }
                if (usb_tx_packet_count(JOYSTICK_ENDPOINT) < TX_PACKET_LIMIT) {
                        tx_packet = usb_malloc();
                        if (tx_packet) break;
                }
                if (++wait_count > TX_TIMEOUT || transmit_previous_timeout) {
                        transmit_previous_timeout = 1;
			//serial_print("error2\n");
                        return -1;
                }
                yield();
        }
	transmit_previous_timeout = 0;
	memcpy(tx_packet->buf, usb_joystick_data, 12);
        tx_packet->len = 12;
        usb_tx(JOYSTICK_ENDPOINT, tx_packet);
	//serial_print("ok\n");
        return 0;
}




#endif // JOYSTICK_INTERFACE