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Diffstat (limited to 'core/wiring_digital.c')
| -rwxr-xr-x | core/wiring_digital.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/core/wiring_digital.c b/core/wiring_digital.c new file mode 100755 index 0000000..1cdbf6c --- /dev/null +++ b/core/wiring_digital.c @@ -0,0 +1,111 @@ +/* + wiring_digital.c - digital input and output functions + Part of Arduino - http://www.arduino.cc/ + + Copyright (c) 2005-2006 David A. Mellis + + 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 + + $Id: wiring.c 248 2007-02-03 15:36:30Z mellis $ +*/ + +#include "wiring_private.h" +#include "pins_arduino.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; +} + +// Forcing this inline keeps the callers from having to push their own stuff +// on the stack. It is a good performance win and only takes 1 more byte per +// user than calling. (It will take more bytes on the 168.) +// +// But shouldn't this be moved into pinMode? Seems silly to check and do on +// each digitalread or write. +// +static inline void turnOffPWM(uint8_t timer) __attribute__ ((always_inline)); +static inline void turnOffPWM(uint8_t timer) +{ + if (timer == TIMER1A) cbi(TCCR1A, COM1A1); + if (timer == TIMER1B) cbi(TCCR1A, COM1B1); + +#if defined(__AVR_ATmega8__) + if (timer == TIMER2) cbi(TCCR2, COM21); +#else + if (timer == TIMER0A) cbi(TCCR0A, COM0A1); + if (timer == TIMER0B) cbi(TCCR0A, COM0B1); + if (timer == TIMER2A) cbi(TCCR2A, COM2A1); + if (timer == TIMER2B) cbi(TCCR2A, COM2B1); +#endif + +#if defined(__AVR_ATmega1280__) + if (timer == TIMER3A) cbi(TCCR3A, COM3A1); + if (timer == TIMER3B) cbi(TCCR3A, COM3B1); + if (timer == TIMER3C) cbi(TCCR3A, COM3C1); + if (timer == TIMER4A) cbi(TCCR4A, COM4A1); + if (timer == TIMER4B) cbi(TCCR4A, COM4B1); + if (timer == TIMER4C) cbi(TCCR4A, COM4C1); + if (timer == TIMER5A) cbi(TCCR5A, COM5A1); + if (timer == TIMER5B) cbi(TCCR5A, COM5B1); + if (timer == TIMER5C) cbi(TCCR5A, COM5C1); +#endif +} + +void digitalWrite(uint8_t pin, uint8_t val) +{ + uint8_t timer = digitalPinToTimer(pin); + uint8_t bit = digitalPinToBitMask(pin); + uint8_t port = digitalPinToPort(pin); + volatile uint8_t *out; + + if (port == NOT_A_PIN) return; + + // If the pin that support PWM output, we need to turn it off + // before doing a digital write. + if (timer != NOT_ON_TIMER) turnOffPWM(timer); + + out = portOutputRegister(port); + + if (val == LOW) *out &= ~bit; + else *out |= bit; +} + +int digitalRead(uint8_t pin) +{ + uint8_t timer = digitalPinToTimer(pin); + uint8_t bit = digitalPinToBitMask(pin); + uint8_t port = digitalPinToPort(pin); + + if (port == NOT_A_PIN) return LOW; + + // If the pin that support PWM output, we need to turn it off + // before getting a digital reading. + if (timer != NOT_ON_TIMER) turnOffPWM(timer); + + if (*portInputRegister(port) & bit) return HIGH; + return LOW; +} |