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Add shiftIn and shiftOut

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Earle F. Philhower, III 2021-03-12 16:14:58 -08:00
parent c30cb6d2f5
commit ceef9c22f0
1 changed files with 49 additions and 0 deletions
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cores/rp2040/wiring_shift.cpp Normal file
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/*
* 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
*/
#include <Arduino.h>
extern "C" 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;
}
extern "C" 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);
}
}