From fe780799e8117ac30f9c05bcd43616638f35e66a Mon Sep 17 00:00:00 2001 From: Romain Forlot Date: Sun, 8 Dec 2019 15:56:39 +0100 Subject: converter: Improve bit_position computation - Fix wrong bit_position swap computed: Need to multiply then lenght in bytes by 8 to get it for bits. - Add a continental bit_position function: This allow to get the correct bit_position using the weird Continental. bit numbering method where the Frame is read using little endianness and bit count using a big endianness - Use define CHAR_BIT instead of hardcoded 8 value Change-Id: I8d458ab457f80e5fa116af942acfceaaef51b763 Signed-off-by: Romain Forlot --- low-can-binding/can/can-decoder.cpp | 7 +++--- low-can-binding/utils/converter.cpp | 50 +++++++++++++++---------------------- low-can-binding/utils/converter.hpp | 3 +++ 3 files changed, 27 insertions(+), 33 deletions(-) diff --git a/low-can-binding/can/can-decoder.cpp b/low-can-binding/can/can-decoder.cpp index 0af488b2..ae10cd98 100644 --- a/low-can-binding/can/can-decoder.cpp +++ b/low-can-binding/can/can-decoder.cpp @@ -16,6 +16,7 @@ */ #include "can-decoder.hpp" +#include #include "canutil/read.h" #include "../utils/openxc-utils.hpp" @@ -41,9 +42,9 @@ int decoder_t::handle_sign(const signal_t& signal, std::vector& data_si if(signal.get_sign() == sign_t::UNSIGNED) return 1; else if(signal.get_sign() == sign_t::SIGN_BIT_EXTERN) { - end_bit = signal.get_bit_sign_position()%8; + end_bit = signal.get_bit_sign_position() % CHAR_BIT; mask = static_cast((1 << (end_bit + 1)) - 1); - data_byte = can_data[signal.get_bit_sign_position()/8] & mask; + data_byte = can_data[signal.get_bit_sign_position() / CHAR_BIT] & mask; } else { end_bit = new_end_bit; @@ -152,7 +153,7 @@ openxc_DynamicField decoder_t::decode_bytes(signal_t& signal, std::shared_ptr new_data = std::vector(); - new_data.reserve((bit_size / 8) + 1); + new_data.reserve((bit_size / CHAR_BIT) + 1); int new_start_byte = 0; int new_end_byte = 0; diff --git a/low-can-binding/utils/converter.cpp b/low-can-binding/utils/converter.cpp index 6392fbdf..c6c2f5e1 100644 --- a/low-can-binding/utils/converter.cpp +++ b/low-can-binding/utils/converter.cpp @@ -19,6 +19,7 @@ #include #include #include +#include /** * @brief Convert hex data to string @@ -51,9 +52,9 @@ std::string converter_t::to_hex(const uint8_t data[], const size_t length) void converter_t::signal_to_bits_bytes(unsigned int bit_position, unsigned int bit_size, int &new_start_byte, int &new_end_byte, uint8_t &new_start_bit, uint8_t &new_end_bit) { new_start_byte = bit_position >> 3; - new_start_bit = bit_position % 8; + new_start_bit = bit_position % CHAR_BIT; new_end_byte = (bit_position + bit_size - 1) >> 3; - new_end_bit = (bit_position + bit_size - 1) % 8; + new_end_bit = (bit_position + bit_size - 1) % CHAR_BIT; } @@ -61,38 +62,27 @@ void converter_t::signal_to_bits_bytes(unsigned int bit_position, unsigned int b * @brief This is to use when you have a big endian CAN frame layout. * It converts the bit position so it matches with little endiant CAN frame layout. * + * @param msg_length Message length in bytes. * @param bit_position Original bit position. - * @param bit_size Size of the data. + * @param bit_size Size of the data. * @return uint32_t New bit position. */ uint32_t converter_t::bit_position_swap(unsigned int msg_length, unsigned int bit_position, unsigned int bit_size) { - return msg_length - bit_position - bit_size; - /* - unsigned int start_byte_position = (unsigned int)(bit_position/8); - unsigned int bit_size_rest = bit_size; - - if((int)(bit_size-(8 + start_byte_position * 8 - bit_position % 8)) > 0) - { - AFB_ERROR("Error: bit_position and bit_size getting out of range"); - return bit_position; - } + return (msg_length * CHAR_BIT) - bit_position - bit_size; +} - if(bit_size <= 8 && - ((bit_position+bit_size) % 8 == bit_size || - (bit_position+bit_size)%8==0)) - { - return (unsigned int)(start_byte_position*8 + (8-bit_size)); - } - else - { - do - { - bit_size_rest = bit_size_rest - ((start_byte_position+1)*8-bit_position); - start_byte_position--; - bit_position = start_byte_position*8; - } while (bit_size_rest>8); - return (unsigned int)(start_byte_position*8 + (8-bit_size_rest)); - } - */ +/** + * @brief This allow to get the correct bit_position using the weird Continental. + * bit numbering method where the Frame is read using little endianness + * and bit count using a big endianness + * + * @param msg_length Message length in bytes. + * @param bit_position Original bit position. + * @param bit_size Size of the data. + * @return uint32_t New bit position. + */ +uint32_t converter_t::continental_bit_position_mess(unsigned int msg_length, unsigned int bit_position, unsigned int bit_size) +{ + return bit_position + (CHAR_BIT - bit_position % CHAR_BIT) - bit_size; } diff --git a/low-can-binding/utils/converter.hpp b/low-can-binding/utils/converter.hpp index 23f8ae77..45e29e9a 100644 --- a/low-can-binding/utils/converter.hpp +++ b/low-can-binding/utils/converter.hpp @@ -32,4 +32,7 @@ class converter_t static uint32_t bit_position_swap(unsigned int msg_length, unsigned int bit_position, unsigned int bit_size); + static uint32_t continental_bit_position_mess(unsigned int msg_length, + unsigned int bit_position, + unsigned int bit_size); }; -- cgit 1.2.3-korg