Rev 2598 |
Blame |
Compare with Previous |
Last modification |
View Log
| RSS feed
/****************************************************************************
* Copyright (C) 2009-2018 by Claas Anders "CaScAdE" Rathje *
* admiralcascade@gmail.com *
* Project-URL: http://www.mylifesucks.de/oss/c-osd/ *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, write to the *
* Free Software Foundation, Inc., *
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
****************************************************************************/
#include "main.h"
#include <avr/io.h>
#include <avr/interrupt.h>
#include "ppm.h"
#include "max7456_software_spi.h" // clearing
#if !(ALLCHARSDEBUG|(WRITECHARS != -1))
volatile uint16_t old_timer1 = 0, ppm = 0;
/**
* init ppm, including timer1 for measurement
*/
void ppm_init() {
PORTE |= (1 << PORTE0); // enable pullup on INT0 pin
GICR |= (1 << INT2); // External Interrupt Request 2 Enable
EMCUCR |= (1 << ISC2); // a rising edge on INT2 activates the interrupt
TCCR1B |= (0 << CS12) | (1 << CS10) | (1 << CS11); // timer1 up with prescaler 64
}
/**
* Handle INT2 interrupts that occur on changing edges of ppm signal
*/
ISR(INT2_vect) {
// since the pin might get bogus reads we wait for 123 signals
static uint8_t valid_ppm_to_go = 123;
if (EMCUCR & (1 << ISC2)) { // rising
old_timer1 = TCNT1;
EMCUCR &= ~(1 << ISC2); // next one is falling
} else {
if (valid_ppm_to_go) {
valid_ppm_to_go--;
} else {
if (TCNT1 > old_timer1 + 256) {
ppm = TCNT1 - old_timer1;
ppm -= 256;
} else {
ppm = 0;
}
if (ppm < 128) { // we want HUD
if (!(COSD_FLAGS_MODES & COSD_FLAG_HUD)) {
COSD_FLAGS_RUNTIME &= ~COSD_ICONS_WRITTEN;
}
COSD_FLAGS_MODES |= COSD_FLAG_HUD;
} else { // we do not want hud
COSD_FLAGS_MODES &= ~COSD_FLAG_HUD;
}
}
EMCUCR |= (1 << ISC2); // next one is rising
}
//write_ndigit_number_u(2, 6, valid_ppm_to_go, 100, 0); // debug
//write_ndigit_number_u(2, 7, COSD_FLAGS_CONFIG, 100, 0); // debug
//PORTC ^= (1 << PC3); // LED4_TOGGLE // debug
//uptime = ppm;
}
#endif