/* * 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 "can-message-definition.hpp" #include "../binding/low-can-hat.hpp" /// @brief Parse the signal's bitfield from the given data and return the raw /// value. /// /// @param[in] signal - The signal to parse from the data. /// @param[in] message - can_message_t to parse /// /// @return Returns the raw value of the signal parsed as a bitfield from the given byte /// array. /// float decoder_t::parseSignalBitfield(can_signal_t& signal, const can_message_t& message) { return bitfield_parse_float(message.get_data(), CAN_MESSAGE_SIZE, signal.get_bit_position(), signal.get_bit_size(), signal.get_factor(), signal.get_offset()); } /// @brief Wrap a raw CAN signal value in a DynamicField without modification. /// /// This is an implementation of the SignalDecoder type signature, and can be /// used directly in the can_signal_t.decoder field. /// /// @param[in] signal - The details of the signal that contains the state mapping. /// @param[in] signals - The list of all signals /// @param[in] value - The numerical value that will be wrapped in a DynamicField. /// @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::noopDecoder(can_signal_t& signal, const std::vector<std::shared_ptr<can_signal_t> >& signals, float value, bool* send) { openxc_DynamicField decoded_value = build_DynamicField(value); return decoded_value; } /// @brief Coerces a numerical value to a boolean. /// /// This is an implementation of the SignalDecoder type signature, and can be /// used directly in the can_signal_t.decoder field. /// /// @param[in] signal - The details of the signal that contains the state mapping. /// @param[in] signals - The list of all signals /// @param[in] value - The numerical value that will be converted to a boolean. /// @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::booleanDecoder(can_signal_t& signal, const std::vector<std::shared_ptr<can_signal_t> >& signals, float value, bool* send) { openxc_DynamicField decoded_value = build_DynamicField(value == 0.0 ? false : true); return decoded_value; } /// @brief Update the metadata for a signal and the newly received value. /// /// This is an implementation of the SignalDecoder type signature, and can be /// used directly in the can_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] signals - The list of all signals. /// @param[in] value - The numerical value that will be converted to a boolean. /// @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::ignoreDecoder(can_signal_t& signal, const std::vector<std::shared_ptr<can_signal_t> >& signals, float value, bool* send) { if(send) *send = false; 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 SignalDecoder type signature, and can be /// used directly in the can_signal_t.decoder field. /// /// @param[in] signal - The details of the signal that contains the state mapping. /// @param[in] signals - The list of all signals. /// @param[in] value - The numerical value that should map to a state. /// @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::stateDecoder(can_signal_t& signal, const std::vector<std::shared_ptr<can_signal_t> >& signals, float value, bool* send) { 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; ERROR(binder_interface, "%s: No state found with index: %d", __FUNCTION__, (int)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 can_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 received CAN message that should contain this signal. /// @param[in] signals - an array of all active signals. /// @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::translateSignal(can_signal_t& signal, const can_message_t& message, const std::vector<std::shared_ptr<can_signal_t> >& signals, bool* send) { float value = decoder_t::parseSignalBitfield(signal, message); DEBUG(binder_interface, "%s: Decoded message from parseSignalBitfield: %f", __FUNCTION__, value); // 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::decodeSignal(signal, value, signals, send); signal.set_received(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); 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 can_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] value - The numerical value that will be converted to a boolean. /// @param[in] signals - an array of all active signals. /// @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::decodeSignal( can_signal_t& signal, float value, const std::vector<std::shared_ptr<can_signal_t> >& signals, bool* send) { SignalDecoder decoder = signal.get_decoder() == nullptr ? noopDecoder : signal.get_decoder(); openxc_DynamicField decoded_value = decoder(signal, signals, value, send); return decoded_value; } /// @brief Decode a transformed, human readable value from an raw CAN signal /// already parsed from a CAN message. /// /// This is the same as decodeSignal but you must parse the bitfield value of the signal from the CAN /// message yourself. This is useful if you need that raw value for something /// else. /// /// @param[in] signal - The details of the signal to decode and forward. /// @param[in] message - Raw CAN message to decode /// @param[in] signals - an array of all active signals. /// @param[out] send - An output parameter that will be flipped to false if the value could /// not be decoded. /// openxc_DynamicField decoder_t::decodeSignal( can_signal_t& signal, const can_message_t& message, const std::vector<std::shared_ptr<can_signal_t> >& signals, bool* send) { float value = parseSignalBitfield(signal, message); return decodeSignal(signal, value, signals, send); } /// /// @brief Decode the payload of an OBD-II PID. /// /// This function matches the type signature for a DiagnosticResponseDecoder, 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); }