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authorDavid A. Mellis <d.mellis@arduino.cc>2007-10-06 14:09:02 +0000
committerDavid A. Mellis <d.mellis@arduino.cc>2007-10-06 14:09:02 +0000
commit72e9f39fbde96b484338cbbd785680e5ab4a2e72 (patch)
treebd441d569bf70c9697ccfbee7c70fa26d67be3a0 /targets/arduino/wiring_digital.c
parentb86a6e051920a4ffdb92bc5b8de7260ff3978117 (diff)
Renaming core to targets.
Diffstat (limited to 'targets/arduino/wiring_digital.c')
-rwxr-xr-xtargets/arduino/wiring_digital.c99
1 files changed, 99 insertions, 0 deletions
diff --git a/targets/arduino/wiring_digital.c b/targets/arduino/wiring_digital.c
new file mode 100755
index 0000000..f38b2e1
--- /dev/null
+++ b/targets/arduino/wiring_digital.c
@@ -0,0 +1,99 @@
+/*
+ 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_ATmega168__)
+ if (timer == TIMER0A) cbi(TCCR0A, COM0A1);
+ if (timer == TIMER0B) cbi(TCCR0A, COM0B1);
+ if (timer == TIMER2A) cbi(TCCR2A, COM2A1);
+ if (timer == TIMER2B) cbi(TCCR2A, COM2B1);
+#else
+ if (timer == TIMER2) cbi(TCCR2, COM21);
+#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;
+}