57 lines
1.4 KiB
C++
57 lines
1.4 KiB
C++
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/*
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Arduino Library for Kangaroo
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Copyright (c) 2013 Dimension Engineering LLC
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http://www.dimensionengineering.com/kangaroo
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Permission to use, copy, modify, and/or distribute this software for any
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purpose with or without fee is hereby granted, provided that the above
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copyright notice and this permission notice appear in all copies.
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THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
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SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
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RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
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NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE
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USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include "Kangaroo.h"
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void KangarooCRC::begin()
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{
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_crc = 0x3fff;
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}
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void KangarooCRC::write(byte data)
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{
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_crc ^= data & 0x7f;
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for (byte bit = 0; bit < 7; bit ++)
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{
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if (_crc & 1)
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{
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_crc >>= 1; _crc ^= 0x22f0;
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}
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else
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{
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_crc >>= 1;
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}
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}
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}
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void KangarooCRC::write(const byte* data, size_t lengthOfData)
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{
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for (size_t i = 0; i < lengthOfData; i ++) { write(data[i]); }
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}
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void KangarooCRC::end()
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{
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_crc ^= 0x3fff;
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}
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uint16_t KangarooCRC::value(const byte* data, size_t lengthOfData)
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{
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KangarooCRC crc;
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crc.begin(); crc.write(data, lengthOfData); crc.end();
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return crc.value();
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}
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