166 lines
4.6 KiB
C
166 lines
4.6 KiB
C
/*
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wiring_digital.c - digital input and output functions
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Part of Arduino - http://www.arduino.cc/
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Copyright (c) 2005-2006 David A. Mellis
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library 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 GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General
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Public License along with this library; if not, write to the
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Free Software Foundation, Inc., 59 Temple Place, Suite 330,
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Boston, MA 02111-1307 USA
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Modified 28 September 2010 by Mark Sproul
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$Id: wiring.c 248 2007-02-03 15:36:30Z mellis $
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*/
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#include "wiring_private.h"
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#include "pins_arduino.h"
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void pinMode(uint8_t pin, uint8_t mode)
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{
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uint8_t bit = digitalPinToBitMask(pin);
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uint8_t port = digitalPinToPort(pin);
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volatile uint8_t *reg;
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if (port == NOT_A_PIN) return;
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// JWS: can I let the optimizer do this?
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reg = portModeRegister(port);
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if (mode == INPUT) {
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uint8_t oldSREG = SREG;
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cli();
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*reg &= ~bit;
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SREG = oldSREG;
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} else {
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uint8_t oldSREG = SREG;
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cli();
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*reg |= bit;
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SREG = oldSREG;
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}
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}
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// Forcing this inline keeps the callers from having to push their own stuff
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// on the stack. It is a good performance win and only takes 1 more byte per
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// user than calling. (It will take more bytes on the 168.)
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//
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// But shouldn't this be moved into pinMode? Seems silly to check and do on
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// each digitalread or write.
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//
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// Mark Sproul:
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// - Removed inline. Save 170 bytes on atmega1280
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// - changed to a switch statment; added 32 bytes but much easier to read and maintain.
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// - Added more #ifdefs, now compiles for atmega645
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//
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//static inline void turnOffPWM(uint8_t timer) __attribute__ ((always_inline));
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//static inline void turnOffPWM(uint8_t timer)
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static void turnOffPWM(uint8_t timer)
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{
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switch (timer)
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{
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#if defined(TCCR1A) && defined(COM1A1)
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case TIMER1A: cbi(TCCR1A, COM1A1); break;
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#endif
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#if defined(TCCR1A) && defined(COM1B1)
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case TIMER1B: cbi(TCCR1A, COM1B1); break;
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#endif
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#if defined(TCCR2) && defined(COM21)
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case TIMER2: cbi(TCCR2, COM21); break;
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#endif
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#if defined(TCCR0A) && defined(COM0A1)
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case TIMER0A: cbi(TCCR0A, COM0A1); break;
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#endif
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#if defined(TIMER0B) && defined(COM0B1)
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case TIMER0B: cbi(TCCR0A, COM0B1); break;
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#endif
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#if defined(TCCR2A) && defined(COM2A1)
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case TIMER2A: cbi(TCCR2A, COM2A1); break;
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#endif
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#if defined(TCCR2A) && defined(COM2B1)
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case TIMER2B: cbi(TCCR2A, COM2B1); break;
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#endif
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#if defined(TCCR3A) && defined(COM3A1)
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case TIMER3A: cbi(TCCR3A, COM3A1); break;
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#endif
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#if defined(TCCR3A) && defined(COM3B1)
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case TIMER3B: cbi(TCCR3A, COM3B1); break;
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#endif
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#if defined(TCCR3A) && defined(COM3C1)
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case TIMER3C: cbi(TCCR3A, COM3C1); break;
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#endif
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#if defined(TCCR4A) && defined(COM4A1)
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case TIMER4A: cbi(TCCR4A, COM4A1); break;
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#endif
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#if defined(TCCR4A) && defined(COM4B1)
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case TIMER4B: cbi(TCCR4A, COM4B1); break;
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#endif
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#if defined(TCCR4A) && defined(COM4C1)
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case TIMER4C: cbi(TCCR4A, COM4C1); break;
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#endif
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#if defined(TCCR5A)
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case TIMER5A: cbi(TCCR5A, COM5A1); break;
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case TIMER5B: cbi(TCCR5A, COM5B1); break;
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case TIMER5C: cbi(TCCR5A, COM5C1); break;
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#endif
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}
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}
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void digitalWrite(uint8_t pin, uint8_t val)
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{
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uint8_t timer = digitalPinToTimer(pin);
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uint8_t bit = digitalPinToBitMask(pin);
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uint8_t port = digitalPinToPort(pin);
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volatile uint8_t *out;
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if (port == NOT_A_PIN) return;
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// If the pin that support PWM output, we need to turn it off
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// before doing a digital write.
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if (timer != NOT_ON_TIMER) turnOffPWM(timer);
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out = portOutputRegister(port);
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if (val == LOW) {
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uint8_t oldSREG = SREG;
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cli();
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*out &= ~bit;
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SREG = oldSREG;
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} else {
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uint8_t oldSREG = SREG;
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cli();
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*out |= bit;
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SREG = oldSREG;
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}
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}
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int digitalRead(uint8_t pin)
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{
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uint8_t timer = digitalPinToTimer(pin);
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uint8_t bit = digitalPinToBitMask(pin);
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uint8_t port = digitalPinToPort(pin);
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if (port == NOT_A_PIN) return LOW;
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// If the pin that support PWM output, we need to turn it off
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// before getting a digital reading.
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if (timer != NOT_ON_TIMER) turnOffPWM(timer);
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if (*portInputRegister(port) & bit) return HIGH;
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return LOW;
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}
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