comparison: sanguino/cores/arduino/wiring_shift.c
sanguino/cores/arduino/wiring_shift.c
- changeset 2
- b373b0288715
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| 1:b584642d4f58 | 2:b373b0288715 |
|---|---|
| 1 /* | |
| 2 wiring_shift.c - shiftOut() function | |
| 3 Part of Arduino - http://www.arduino.cc/ | |
| 4 | |
| 5 Copyright (c) 2005-2006 David A. Mellis | |
| 6 | |
| 7 This library is free software; you can redistribute it and/or | |
| 8 modify it under the terms of the GNU Lesser General Public | |
| 9 License as published by the Free Software Foundation; either | |
| 10 version 2.1 of the License, or (at your option) any later version. | |
| 11 | |
| 12 This library is distributed in the hope that it will be useful, | |
| 13 but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 15 Lesser General Public License for more details. | |
| 16 | |
| 17 You should have received a copy of the GNU Lesser General | |
| 18 Public License along with this library; if not, write to the | |
| 19 Free Software Foundation, Inc., 59 Temple Place, Suite 330, | |
| 20 Boston, MA 02111-1307 USA | |
| 21 | |
| 22 $Id: wiring.c 248 2007-02-03 15:36:30Z mellis $ | |
| 23 */ | |
| 24 | |
| 25 #include "wiring_private.h" | |
| 26 | |
| 27 uint8_t shiftIn(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder) { | |
| 28 uint8_t value = 0; | |
| 29 uint8_t i; | |
| 30 | |
| 31 for (i = 0; i < 8; ++i) { | |
| 32 digitalWrite(clockPin, HIGH); | |
| 33 if (bitOrder == LSBFIRST) | |
| 34 value |= digitalRead(dataPin) << i; | |
| 35 else | |
| 36 value |= digitalRead(dataPin) << (7 - i); | |
| 37 digitalWrite(clockPin, LOW); | |
| 38 } | |
| 39 return value; | |
| 40 } | |
| 41 | |
| 42 void shiftOut(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder, uint8_t val) | |
| 43 { | |
| 44 uint8_t i; | |
| 45 | |
| 46 for (i = 0; i < 8; i++) { | |
| 47 if (bitOrder == LSBFIRST) | |
| 48 digitalWrite(dataPin, !!(val & (1 << i))); | |
| 49 else | |
| 50 digitalWrite(dataPin, !!(val & (1 << (7 - i)))); | |
| 51 | |
| 52 digitalWrite(clockPin, HIGH); | |
| 53 digitalWrite(clockPin, LOW); | |
| 54 } | |
| 55 } |
