00001 //============================================================================== 00002 // Copyright (c) 2012, Johannes Meyer, TU Darmstadt 00003 // All rights reserved. 00004 00005 // Redistribution and use in source and binary forms, with or without 00006 // modification, are permitted provided that the following conditions are met: 00007 // * Redistributions of source code must retain the above copyright 00008 // notice, this list of conditions and the following disclaimer. 00009 // * Redistributions in binary form must reproduce the above copyright 00010 // notice, this list of conditions and the following disclaimer in the 00011 // documentation and/or other materials provided with the distribution. 00012 // * Neither the name of the Flight Systems and Automatic Control group, 00013 // TU Darmstadt, nor the names of its contributors may be used to 00014 // endorse or promote products derived from this software without 00015 // specific prior written permission. 00016 00017 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 00018 // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 00019 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 00020 // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY 00021 // DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 00022 // (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 00023 // LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 00024 // ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 00025 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 00026 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 00027 //============================================================================== 00028 00029 #ifndef UBLOX_MSGS_CHECKSUM_H 00030 #define UBLOX_MSGS_CHECKSUM_H 00031 00032 #include <stdint.h> 00033 00034 namespace ublox { 00035 00043 static inline void calculateChecksum(const uint8_t *data, 00044 uint32_t size, 00045 uint8_t &ck_a, 00046 uint8_t &ck_b) { 00047 ck_a = 0; ck_b = 0; 00048 for(uint32_t i = 0; i < size; ++i) 00049 { 00050 ck_a = ck_a + data[i]; 00051 ck_b = ck_b + ck_a; 00052 } 00053 } 00054 00062 static inline uint16_t calculateChecksum(const uint8_t *data, 00063 uint32_t size, 00064 uint16_t &checksum) { 00065 uint8_t *byte = reinterpret_cast<uint8_t *>(&checksum); 00066 calculateChecksum(data, size, byte[0], byte[1]); 00067 return checksum; 00068 } 00069 00070 } // namespace ublox 00071 00072 #endif // UBLOX_MSGS_CHECKSUM_H