Diff: wiring_shift.c

Revision:

2:7e1ff33bc76a

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wiring_shift.c	Sat Jun 04 20:01:33 2011 +0000
@@ -0,0 +1,55 @@
+/*
+  wiring_shift.c - shiftOut() function
+  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"
+
+uint8_t shiftIn(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder) {
+	uint8_t value = 0;
+	uint8_t i;
+
+	for (i = 0; i < 8; ++i) {
+		digitalWrite(clockPin, HIGH);
+		if (bitOrder == LSBFIRST)
+			value |= digitalRead(dataPin) << i;
+		else
+			value |= digitalRead(dataPin) << (7 - i);
+		digitalWrite(clockPin, LOW);
+	}
+	return value;
+}
+
+void shiftOut(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder, uint8_t val)
+{
+	uint8_t i;
+
+	for (i = 0; i < 8; i++)  {
+		if (bitOrder == LSBFIRST)
+			digitalWrite(dataPin, !!(val & (1 << i)));
+		else	
+			digitalWrite(dataPin, !!(val & (1 << (7 - i))));
+			
+		digitalWrite(clockPin, HIGH);
+		digitalWrite(clockPin, LOW);		
+	}
+}