#include "../binding/low-can-hat.hpp"
#include "../utils/converter.hpp"
+/// @brief Handle sign of the signal according to several decoding methods
+///
+/// @param[in] signal - The signal
+/// @param[in] data_signal - The data of the signal
+/// @param[in] new_end_bit - The last bit of in the last byte of the data (data_signal[0])
+/// @param[in] can_data - The whole can data (needed for SIGN BIT EXTERN)
+///
+/// @return Returns the sign of the data
+///
+int decoder_t::handle_sign(const signal_t& signal, std::vector<uint8_t>& data_signal, uint8_t new_end_bit, const std::vector<uint8_t>& can_data)
+{
+ uint8_t data_byte = 0;
+ uint8_t mask = 0;
+ int end_bit = 0;
+
+ 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;
+ mask = static_cast<uint8_t>((1 << (end_bit + 1)) - 1);
+ data_byte = can_data[signal.get_bit_sign_position()/8] & mask;
+ }
+ else {
+ end_bit = new_end_bit;
+ mask = static_cast<uint8_t>((1 << (end_bit + 1)) - 1);
+ data_byte = data_signal[0] & mask;
+ }
+
+ //if negative: decode with right method
+ if(data_byte >> end_bit) {
+ switch(signal.get_sign())
+ {
+ //remove the sign bit to get the absolute value
+ case sign_t::SIGN_BIT:
+ data_signal[0] = static_cast<uint8_t>(data_signal[0] & (mask >> 1));
+ break;
+ //same method twos complement = ones complement + 1
+ case sign_t::ONES_COMPLEMENT:
+ case sign_t::TWOS_COMPLEMENT:
+ //complement only until end_bit
+ data_signal[0] = ((data_signal[0] ^ mask) & mask);
+ if(data_signal.size() > 1) {
+ for(int i=1; i < data_signal.size(); i++) {
+ data_signal[i] = data_signal[i] ^ 0xFF;
+ }
+ }
+ if(signal.get_sign() == sign_t::TWOS_COMPLEMENT)
+ data_signal[data_signal.size() - 1] = static_cast<uint8_t>(data_signal[data_signal.size() - 1] + 1);
+ break;
+ case sign_t::SIGN_BIT_EXTERN:
+ break;
+ default:
+ AFB_ERROR("Not a valid sign entry %d, considering the value as unsigned", signal.get_sign());
+ break;
+ }
+ return -1;
+ }
+ return 1;
+}
+
/// @brief Parses the signal's bitfield from the given data and returns the raw
/// value.
///
uint8_t bit_size = (uint8_t) signal.get_bit_size();
uint32_t bit_position = signal.get_bit_position();
+ if(!signal.get_message()->frame_layout_is_little())
+ {
+ bit_position = converter_t::bit_position_swap(message->get_length(),
+ signal.get_bit_position(),
+ signal.get_bit_size());
+ message->frame_swap();
+ }
+
int new_start_byte = 0;
int new_end_byte = 0;
uint8_t new_start_bit = 0;
for(int i=new_start_byte;i<=new_end_byte;i++)
data_signal.push_back(data[i]);
-// if(bit_size > 255)
-// AFB_ERROR("Error signal %s to long bit size",signal.get_name().c_str());
-
-// if(new_start_bit > 255)
-// AFB_ERROR("Too long signal offset %d", new_start_bit);
+ int sign = decoder_t::handle_sign(signal, data_signal, new_end_bit, data);
if(data_signal.size() > 65535)
- AFB_ERROR("Too long data signal %s",signal.get_name().c_str());
+ AFB_ERROR("Too long data signal %s", signal.get_name().c_str());
- return bitfield_parse_float(data_signal.data(), (uint16_t) data_signal.size(),
+ return static_cast<float>(sign) * bitfield_parse_float(data_signal.data(), (uint16_t) data_signal.size(),
new_start_bit, bit_size, signal.get_factor(),
signal.get_offset());
}
uint32_t length = message->get_length();
uint32_t bit_position = signal.get_bit_position();
uint32_t bit_size = signal.get_bit_size();
+
std::vector<uint8_t> new_data = std::vector<uint8_t>();
- new_data.reserve(bit_size << 3);
+ new_data.reserve((bit_size / 8) + 1);
int new_start_byte = 0;
int new_end_byte = 0;
converter_t::signal_to_bits_bytes(bit_position, bit_size, new_start_byte, new_end_byte, new_start_bit, new_end_bit);
if(new_end_byte >= length)
- {
new_end_byte = length-1;
- }
if(new_start_byte >= length)
{
- AFB_ERROR("Error in description of signals");
+ AFB_ERROR("Error in signal's description");
return decoded_value;
}
- uint8_t first = data[new_start_byte];
- int mask_first = 0;
- for(i=new_start_bit;i<8;i++)
- {
- mask_first = mask_first | (1 << i);
- }
+ uint8_t mask_first_v = static_cast<uint8_t>(0xFF << new_start_bit);
+ uint8_t mask_last_v = static_cast<uint8_t>(0xFF >> (7 - new_end_bit));
- uint8_t mask_first_v = 0;
- if(mask_first > 255)
+ if(new_start_byte == new_end_byte)
{
- AFB_ERROR("Error mask decode bytes");
+ data[new_start_byte] = data[new_start_byte] & (mask_first_v & mask_last_v);
}
else
{
- mask_first_v = (uint8_t)mask_first;
+ data[new_start_byte] = data[new_start_byte] & mask_first_v;
+ data[new_end_byte] = data[new_end_byte] & mask_last_v;
}
- data[new_start_byte]=first&mask_first_v;
-
- uint8_t last = data[new_end_byte];
- int mask_last = 0;
- for(i=0;i<=new_end_bit;i++)
- {
- mask_last = mask_last | (1 << (7-i));
- }
-
- uint8_t mask_last_v = 0;
- if(mask_last > 255)
- {
- AFB_ERROR("Error mask decode bytes");
- }
- else
- {
- mask_last_v = (uint8_t)mask_last;
- }
-
- data[new_end_byte]=last&mask_last_v;
-
-
- for(i=new_start_byte;i<=new_end_byte;i++)
- {
+ for(i=new_start_byte ; i <= new_end_byte ; i++)
new_data.push_back(data[i]);
- }
decoded_value = build_DynamicField(new_data);
// Don't send if they is no changes
if ((signal.get_last_value() == value && !signal.get_send_same()) || !*send )
- {
*send = false;
- }
+
signal.set_last_value(value);
///
openxc_DynamicField decoder_t::translate_signal(signal_t& signal, std::shared_ptr<message_t> message, bool* send)
{
-
// Must call the decoders every time, regardless of if we are going to
// decide to send the signal or not.
openxc_DynamicField decoded_value = decoder_t::decode_signal(signal,
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