osd-contiki/platform/avr-ravenusb/contiki-raven-default-init-lowlevel.c

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/*
* Copyright (c) 2006, Technical University of Munich
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*
* Author: Simon Barner <barner@in.tum.de>
*
* @(#)$$
*/
#include "contiki-raven.h"
#include "contiki.h"
#include "usb_drv.h"
#include "usb_descriptors.h"
#include "usb_specific_request.h"
#include <util/delay.h>
uint8_t checkForFinger(void);
void
init_lowlevel(void)
{
Leds_init();
Leds_off();
if (checkForFinger()) {
usb_mode = mass_storage;
}
return;
}
uint8_t checkForFinger(void)
{
uint8_t tests;
uint8_t matches;
/*
Three pads on RZUSBSTICK go: GND PD3 PD2
We pulse PD3, and check for that pattern on PD2.
A (moist) finger across those three pads should be enough
to bridge these
*/
//Output
DDRD |= 1<<PD3;
//Input
DDRD &= ~(1<<PD2);
tests = 100;
matches = 0;
while(tests) {
//Set bit PD3 to value of LSB of 'tests'
PORTD = (PORTD & ~(1<<PD3)) | ( (tests & 0x01) << PD3);
//Allow changes to propogate
_delay_us(1);
//Check if PD2 matches what we set PD3 to
if ((PIND & (1<<PD2)) == ((tests & 0x01) << PD2)) {
matches++;
}
tests--;
}
if (matches > 70) {
return 1;
}
return 0;
}