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digitals.c
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digitals.c
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/*
digitals.c - digital input and output functions
Based on Arduino code - http://www.arduino.cc/
Copyright (c) 2008-2009 Patrick Bellasi
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General
Public License along with this library; if not, write to the
Free Software Foundation, Inc., 59 Temple Place, Suite 330,
Boston, MA 02111-1307 USA
*/
#include "pins.h"
void pinMode(uint8_t pin, uint8_t mode) {
uint8_t bit = digitalPinToBitMask(pin);
uint8_t port = digitalPinToPort(pin);
volatile uint8_t *reg;
if (port == NOT_A_PIN) return;
// JWS: can I let the optimizer do this?
reg = portModeRegister(port);
if (mode == INPUT) *reg &= ~bit;
else *reg |= bit;
}
void digitalWrite(uint8_t pin, uint8_t val) {
uint8_t bit = digitalPinToBitMask(pin);
uint8_t port = digitalPinToPort(pin);
volatile uint8_t *out;
if (port == NOT_A_PIN) return;
out = portOutputRegister(port);
if (val == LOW) *out &= ~bit;
else *out |= bit;
}
void digitalSwitch(uint8_t pin) {
uint8_t bit = digitalPinToBitMask(pin);
uint8_t port = digitalPinToPort(pin);
volatile uint8_t *out;
if (port == NOT_A_PIN) return;
out = portOutputRegister(port);
if ( *out & bit) *out &= ~bit;
else *out |= bit;
}
int digitalRead(uint8_t pin) {
uint8_t bit = digitalPinToBitMask(pin);
uint8_t port = digitalPinToPort(pin);
if (port == NOT_A_PIN) return LOW;
if (*portInputRegister(port) & bit) return HIGH;
return LOW;
}