56 lines
1.6 KiB
C
56 lines
1.6 KiB
C
![]() |
/*
|
||
|
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);
|
||
|
}
|
||
|
}
|