53 lines
1.4 KiB
C
53 lines
1.4 KiB
C
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/*
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Copyright 2014 Kai Ryu <kai1103@gmail.com>
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <avr/io.h>
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#include <avr/interrupt.h>
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#include <avr/pgmspace.h>
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#include "backlight.h"
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static const uint8_t backlight_table[] PROGMEM = {
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0, 16, 128, 255
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};
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/* Backlight pin configuration
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* PWM: PC6(OC3A)
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*/
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void backlight_set(uint8_t level)
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{
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if (level > 0) {
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// Turn on PWM
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cli();
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DDRC |= (1<<PC6);
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TCCR3A |= ( (1<<WGM30) | (1<<COM3A1) );
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TCCR3B |= ( (1<<CS31) | (1<<CS30) );
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sei();
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// Set PWM
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OCR3A = pgm_read_byte(&backlight_table[level]);
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}
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else {
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// Turn off PWM
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cli();
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DDRC &= ~(1<<PC6);
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TCCR3A &= ~( (1<<WGM30) | (1<<COM3A1) );
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TCCR3B &= ~( (1<<CS31) | (1<<CS30) );
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sei();
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// Set PWM
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OCR3A = 0;
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}
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}
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