3 * Emulate some of the Arduino wiring functionality.
5 * Copyright (c) 2009-2012 Gordon Henderson.
6 ***********************************************************************
7 * This file is part of wiringPi:
8 * https://projects.drogon.net/raspberry-pi/wiringpi/
10 * wiringPi is free software: you can redistribute it and/or modify
11 * it under the terms of the GNU Lesser General Public License as published by
12 * the Free Software Foundation, either version 3 of the License, or
13 * (at your option) any later version.
15 * wiringPi is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU Lesser General Public License for more details.
20 * You should have received a copy of the GNU Lesser General Public License
21 * along with wiringPi. If not, see <http://www.gnu.org/licenses/>.
22 ***********************************************************************
28 #include "wiringShift.h"
32 * Shift data in from a clocked source
33 *********************************************************************************
36 uint8_t shiftIn (uint8_t dPin, uint8_t cPin, uint8_t order)
41 if (order == MSBFIRST)
42 for (i = 7 ; i >= 0 ; --i)
44 digitalWrite (cPin, HIGH) ;
45 value |= digitalRead (dPin) << i ;
46 digitalWrite (cPin, LOW) ;
49 for (i = 0 ; i < 8 ; ++i)
51 digitalWrite (cPin, HIGH) ;
52 value |= digitalRead (dPin) << i ;
53 digitalWrite (cPin, LOW) ;
61 * Shift data out to a clocked source
62 *********************************************************************************
65 void shiftOut (uint8_t dPin, uint8_t cPin, uint8_t order, uint8_t val)
69 if (order == MSBFIRST)
70 for (i = 7 ; i >= 0 ; --i)
72 digitalWrite (dPin, val & (1 << i)) ;
73 digitalWrite (cPin, HIGH) ;
74 digitalWrite (cPin, LOW) ;
77 for (i = 0 ; i < 8 ; ++i)
79 digitalWrite (dPin, val & (1 << i)) ;
80 digitalWrite (cPin, HIGH) ;
81 digitalWrite (cPin, LOW) ;