/* * Copyright (C) 2015, 2016 "IoT.bzh" * Author "Romain Forlot" <romain.forlot@iot.bzh> * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "can-decoder.hpp" #include "canutil/read.h" #include "../utils/openxc-utils.hpp" #include "message-definition.hpp" #include "../binding/low-can-hat.hpp" #include "../utils/converter.hpp" /// @brief Parses the signal's bitfield from the given data and returns the raw /// value. /// /// @param[in] signal - The signal to be parsed from the data. /// @param[in] message - message_t to parse /// /// @return Returns the raw value of the signal parsed as a bitfield from the given byte /// array. /// float decoder_t::parse_signal_bitfield(signal_t& signal, std::shared_ptr<message_t> message) { const std::vector<uint8_t> data = message->get_data_vector(); std::vector<uint8_t> data_signal; uint32_t bit_size = signal.get_bit_size(); uint32_t bit_position = signal.get_bit_position(); int new_start_byte = 0; int new_end_byte = 0; int new_start_bit = 0; int new_end_bit = 0; converter_t::signal_to_bits_bytes(bit_position, bit_size, new_start_byte, new_end_byte, new_start_bit, new_end_bit); for(int i=new_start_byte;i<=new_end_byte;i++) { data_signal.push_back(data[i]); } uint8_t new_bit_size = 0; if(bit_size > 255) { AFB_ERROR("Error signal %s to long bit size",signal.get_name().c_str()); } else { new_bit_size = (uint8_t) bit_size; } uint8_t bit_offset = 0; if(new_start_bit > 255) { AFB_ERROR("Too long signal offset %d", new_start_bit); } else { bit_offset = (uint8_t) new_start_bit; } uint16_t length = 0; if(data_signal.size() > 65535) { AFB_ERROR("Too long data signal %s",signal.get_name().c_str()); } else { length = (uint16_t) data_signal.size(); } return bitfield_parse_float(data_signal.data(), length, bit_offset, new_bit_size, signal.get_factor(), signal.get_offset()); } /// @brief Decode and return string bytes (hex) for a CAN signal's. /// /// This is an implementation of the Signal type signature, and can be /// used directly in the signal_t.decoder field. /// /// @param[in] signal - The details of the signal. /// @param[in] message - The message with data to decode. /// @param[out] send - An output argument that will be set to false if the value should /// not be sent for any reason. /// /// @return Returns a DynamicField with a string value of bytes (hex) /// openxc_DynamicField decoder_t::decode_bytes(signal_t& signal, std::shared_ptr<message_t> message, bool* send) { int i=0; openxc_DynamicField decoded_value; std::vector<uint8_t> data = message->get_data_vector(); 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); int new_start_byte = 0; int new_end_byte = 0; int new_start_bit = 0; int new_end_bit = 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"); 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 = 0; if(mask_first > 255) { AFB_ERROR("Error mask decode bytes"); } else { mask_first_v = (uint8_t)mask_first; } 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++) { new_data.push_back(data[i]); } decoded_value = build_DynamicField(new_data); return decoded_value; } /// @brief Wraps a raw CAN signal value in a DynamicField without modification. /// /// This is an implementation of the Signal type signature, and can be /// used directly in the signal_t.decoder field. /// /// @param[in] signal - The details of the signal that contains the state mapping. /// @param[in] message - The message with data to decode. /// @param[out] send - An output argument that will be set to false if the value should /// not be sent for any reason. /// /// @return Returns a DynamicField with the original, unmodified raw CAN signal value as /// its numeric value. The 'send' argument will not be modified as this decoder /// always succeeds. /// openxc_DynamicField decoder_t::decode_noop(signal_t& signal, std::shared_ptr<message_t> message, bool* send) { float value = decoder_t::parse_signal_bitfield(signal, message); AFB_DEBUG("Decoded message from parse_signal_bitfield: %f", value); openxc_DynamicField decoded_value = build_DynamicField(value); // 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); return decoded_value; } /// @brief Coerces a numerical value to a boolean. /// /// This is an implementation of the Signal type signature, and can be /// used directly in the signal_t.decoder field. /// /// @param[in] signal - The details of the signal that contains the state mapping. /// @param[in] message - The message with data to decode. /// @param[out] send - An output argument that will be set to false if the value should /// not be sent for any reason. /// /// @return Returns a DynamicField with a boolean value of false if the raw signal value /// is 0.0, otherwise true. The 'send' argument will not be modified as this /// decoder always succeeds. /// openxc_DynamicField decoder_t::decode_boolean(signal_t& signal, std::shared_ptr<message_t> message, bool* send) { float value = decoder_t::parse_signal_bitfield(signal, message); AFB_DEBUG("Decoded message from parse_signal_bitfield: %f", value); openxc_DynamicField decoded_value = build_DynamicField(value == 0.0 ? false : true); // 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); return decoded_value; } /// @brief Update the metadata for a signal and the newly received value. /// /// This is an implementation of the Signal type signature, and can be /// used directly in the signal_t.decoder field. /// /// This function always flips 'send' to false. /// /// @param[in] signal - The details of the signal that contains the state mapping. /// @param[in] message - The message with data to decode. /// @param[out] send - This output argument will always be set to false, so the caller will /// know not to publish this value to the pipeline. /// /// @return Return value is undefined. /// openxc_DynamicField decoder_t::decode_ignore(signal_t& signal, std::shared_ptr<message_t> message, bool* send) { float value = decoder_t::parse_signal_bitfield(signal, message); if(send) *send = false; signal.set_last_value(value); openxc_DynamicField decoded_value; return decoded_value; } /// @brief Find and return the corresponding string state for a CAN signal's /// raw integer value. /// /// This is an implementation of the Signal type signature, and can be /// used directly in the signal_t.decoder field. /// /// @param[in] signal - The details of the signal that contains the state mapping. /// @param[in] message - The message with data to decode. /// @param[out] send - An output argument that will be set to false if the value should /// not be sent for any reason. /// /// @return Returns a DynamicField with a string value if a matching state is found in /// the signal. If an equivalent isn't found, send is sent to false and the /// return value is undefined. /// openxc_DynamicField decoder_t::decode_state(signal_t& signal, std::shared_ptr<message_t> message, bool* send) { float value = decoder_t::parse_signal_bitfield(signal, message); AFB_DEBUG("Decoded message from parse_signal_bitfield: %f", value); const std::string signal_state = signal.get_states((uint8_t)value); openxc_DynamicField decoded_value = build_DynamicField(signal_state); if(signal_state.size() <= 0) { *send = false; AFB_ERROR("No state found with index: %d", (int)value); } // 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); return decoded_value; } /// @brief Parse a signal from a CAN message, apply any required transforations /// to get a human readable value and public the result to the pipeline. /// /// If the signal_t has a non-NULL 'decoder' field, the raw CAN signal value /// will be passed to the decoder before publishing. /// /// @param[in] signal - The details of the signal to decode and forward. /// @param[in] message - The message with data to decode. /// @param[out] send - An output parameter that will be flipped to false if the value could /// not be decoded. /// /// The decoder returns an openxc_DynamicField, which may contain a number, /// string or boolean. /// 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, message, send); signal.set_received(true); signal.set_timestamp(message->get_timestamp()); signal.get_message()->set_last_value(message); return decoded_value; } /// @brief Parse a signal from a CAN message and apply any required /// transforations to get a human readable value. /// /// If the signal_t has a non-NULL 'decoder' field, the raw CAN signal value /// will be passed to the decoder before returning. /// /// @param[in] signal - The details of the signal to decode and forward. /// @param[in] message - The message with data to decode. /// @param[out] send - An output parameter that will be flipped to false if the value could /// not be decoded. /// /// @return The decoder returns an openxc_DynamicField, which may contain a number, /// string or boolean. If 'send' is false, the return value is undefined. /// openxc_DynamicField decoder_t::decode_signal( signal_t& signal, std::shared_ptr<message_t> message, bool* send) { signal_decoder decoder = signal.get_decoder() == nullptr ? decode_noop : signal.get_decoder(); openxc_DynamicField decoded_value = decoder(signal, message, send); return decoded_value; } /// /// @brief Decode the payload of an OBD-II PID. /// /// This function matches the type signature for a DiagnosticResponse, so /// it can be used as the decoder for a DiagnosticRequest. It returns the decoded /// value of the PID, using the standard formulas (see /// http://en.wikipedia.org/wiki/OBD-II_PIDs#Mode_01). /// /// @param[in] response - the received DiagnosticResponse (the data is in response.payload, /// a byte array). This is most often used when the byte order is /// signiticant, i.e. with many OBD-II PID formulas. /// @param[in] parsed_payload - the entire payload of the response parsed as an int. /// /// @return Float decoded value. /// float decoder_t::decode_obd2_response(const DiagnosticResponse* response, float parsed_payload) { return diagnostic_decode_obd2_pid(response); }