2 * Copyright (C) 2015, 2016 "IoT.bzh"
3 * Author "Romain Forlot" <romain.forlot@iot.bzh>
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
18 #include "can-decoder.hpp"
20 #include "canutil/read.h"
21 #include "../utils/openxc-utils.hpp"
22 #include "message-definition.hpp"
23 #include "../binding/low-can-hat.hpp"
24 #include "../utils/converter.hpp"
26 /// @brief Parses the signal's bitfield from the given data and returns the raw
29 /// @param[in] signal - The signal to be parsed from the data.
30 /// @param[in] message - message_t to parse
32 /// @return Returns the raw value of the signal parsed as a bitfield from the given byte
35 float decoder_t::parse_signal_bitfield(signal_t& signal, std::shared_ptr<message_t> message)
37 const std::vector<uint8_t> data = message->get_data_vector();
38 std::vector<uint8_t> data_signal;
39 uint8_t bit_size = (uint8_t) signal.get_bit_size();
40 uint32_t bit_position = signal.get_bit_position();
42 int new_start_byte = 0;
44 uint8_t new_start_bit = 0;
45 uint8_t new_end_bit = 0;
47 converter_t::signal_to_bits_bytes(bit_position, bit_size, new_start_byte, new_end_byte, new_start_bit, new_end_bit);
49 for(int i=new_start_byte;i<=new_end_byte;i++)
50 data_signal.push_back(data[i]);
53 // AFB_ERROR("Error signal %s to long bit size", signal.get_name().c_str());
55 // if(new_start_bit > 255)
56 // AFB_ERROR("Too long signal offset %d", new_start_bit);
58 if(data_signal.size() > 65535)
59 AFB_ERROR("Too long data signal %s", signal.get_name().c_str());
61 return bitfield_parse_float(data_signal.data(), (uint16_t) data_signal.size(),
62 new_start_bit, bit_size, signal.get_factor(),
67 /// @brief Decode and return string bytes (hex) for a CAN signal's.
69 /// This is an implementation of the Signal type signature, and can be
70 /// used directly in the signal_t.decoder field.
72 /// @param[in] signal - The details of the signal.
73 /// @param[in] message - The message with data to decode.
74 /// @param[out] send - An output argument that will be set to false if the value should
75 /// not be sent for any reason.
77 /// @return Returns a DynamicField with a string value of bytes (hex)
79 openxc_DynamicField decoder_t::decode_bytes(signal_t& signal, std::shared_ptr<message_t> message, bool* send)
82 openxc_DynamicField decoded_value;
83 std::vector<uint8_t> data = message->get_data_vector();
84 uint32_t length = message->get_length();
85 uint32_t bit_position = signal.get_bit_position();
86 uint32_t bit_size = signal.get_bit_size();
87 std::vector<uint8_t> new_data = std::vector<uint8_t>();
88 new_data.reserve(bit_size << 3);
90 int new_start_byte = 0;
92 uint8_t new_start_bit = 0;
93 uint8_t new_end_bit = 0;
95 converter_t::signal_to_bits_bytes(bit_position, bit_size, new_start_byte, new_end_byte, new_start_bit, new_end_bit);
97 if(new_end_byte >= length)
99 new_end_byte = length-1;
102 if(new_start_byte >= length)
104 AFB_ERROR("Error in description of signals");
105 return decoded_value;
108 uint8_t first = data[new_start_byte];
110 for(i=new_start_bit;i<8;i++)
112 mask_first = mask_first | (1 << i);
115 uint8_t mask_first_v = 0;
118 AFB_ERROR("Error mask decode bytes");
122 mask_first_v = (uint8_t)mask_first;
125 data[new_start_byte]=first&mask_first_v;
127 uint8_t last = data[new_end_byte];
129 for(i=0;i<=new_end_bit;i++)
131 mask_last = mask_last | (1 << (7-i));
134 uint8_t mask_last_v = 0;
137 AFB_ERROR("Error mask decode bytes");
141 mask_last_v = (uint8_t)mask_last;
144 data[new_end_byte]=last&mask_last_v;
147 for(i=new_start_byte;i<=new_end_byte;i++)
149 new_data.push_back(data[i]);
152 decoded_value = build_DynamicField(new_data);
154 return decoded_value;
157 /// @brief Wraps a raw CAN signal value in a DynamicField without modification.
159 /// This is an implementation of the Signal type signature, and can be
160 /// used directly in the signal_t.decoder field.
162 /// @param[in] signal - The details of the signal that contains the state mapping.
163 /// @param[in] message - The message with data to decode.
164 /// @param[out] send - An output argument that will be set to false if the value should
165 /// not be sent for any reason.
167 /// @return Returns a DynamicField with the original, unmodified raw CAN signal value as
168 /// its numeric value. The 'send' argument will not be modified as this decoder
171 openxc_DynamicField decoder_t::decode_noop(signal_t& signal, std::shared_ptr<message_t> message, bool* send)
173 float value = decoder_t::parse_signal_bitfield(signal, message);
174 AFB_DEBUG("Decoded message from parse_signal_bitfield: %f", value);
175 openxc_DynamicField decoded_value = build_DynamicField(value);
177 // Don't send if they is no changes
178 if ((signal.get_last_value() == value && !signal.get_send_same()) || !*send )
182 signal.set_last_value(value);
184 return decoded_value;
186 /// @brief Coerces a numerical value to a boolean.
188 /// This is an implementation of the Signal type signature, and can be
189 /// used directly in the signal_t.decoder field.
191 /// @param[in] signal - The details of the signal that contains the state mapping.
192 /// @param[in] message - The message with data to decode.
193 /// @param[out] send - An output argument that will be set to false if the value should
194 /// not be sent for any reason.
196 /// @return Returns a DynamicField with a boolean value of false if the raw signal value
197 /// is 0.0, otherwise true. The 'send' argument will not be modified as this
198 /// decoder always succeeds.
200 openxc_DynamicField decoder_t::decode_boolean(signal_t& signal, std::shared_ptr<message_t> message, bool* send)
202 float value = decoder_t::parse_signal_bitfield(signal, message);
203 AFB_DEBUG("Decoded message from parse_signal_bitfield: %f", value);
204 openxc_DynamicField decoded_value = build_DynamicField(value == 0.0 ? false : true);
206 // Don't send if they is no changes
207 if ((signal.get_last_value() == value && !signal.get_send_same()) || !*send )
211 signal.set_last_value(value);
214 return decoded_value;
216 /// @brief Update the metadata for a signal and the newly received value.
218 /// This is an implementation of the Signal type signature, and can be
219 /// used directly in the signal_t.decoder field.
221 /// This function always flips 'send' to false.
223 /// @param[in] signal - The details of the signal that contains the state mapping.
224 /// @param[in] message - The message with data to decode.
225 /// @param[out] send - This output argument will always be set to false, so the caller will
226 /// know not to publish this value to the pipeline.
228 /// @return Return value is undefined.
230 openxc_DynamicField decoder_t::decode_ignore(signal_t& signal, std::shared_ptr<message_t> message, bool* send)
232 float value = decoder_t::parse_signal_bitfield(signal, message);
236 signal.set_last_value(value);
237 openxc_DynamicField decoded_value;
239 return decoded_value;
242 /// @brief Find and return the corresponding string state for a CAN signal's
243 /// raw integer value.
245 /// This is an implementation of the Signal type signature, and can be
246 /// used directly in the signal_t.decoder field.
248 /// @param[in] signal - The details of the signal that contains the state mapping.
249 /// @param[in] message - The message with data to decode.
250 /// @param[out] send - An output argument that will be set to false if the value should
251 /// not be sent for any reason.
253 /// @return Returns a DynamicField with a string value if a matching state is found in
254 /// the signal. If an equivalent isn't found, send is sent to false and the
255 /// return value is undefined.
257 openxc_DynamicField decoder_t::decode_state(signal_t& signal, std::shared_ptr<message_t> message, bool* send)
259 float value = decoder_t::parse_signal_bitfield(signal, message);
260 AFB_DEBUG("Decoded message from parse_signal_bitfield: %f", value);
261 const std::string signal_state = signal.get_states((uint8_t)value);
262 openxc_DynamicField decoded_value = build_DynamicField(signal_state);
263 if(signal_state.size() <= 0)
266 AFB_ERROR("No state found with index: %d", (int)value);
269 // Don't send if they is no changes
270 if ((signal.get_last_value() == value && !signal.get_send_same()) || !*send )
274 signal.set_last_value(value);
277 return decoded_value;
281 /// @brief Parse a signal from a CAN message, apply any required transforations
282 /// to get a human readable value and public the result to the pipeline.
284 /// If the signal_t has a non-NULL 'decoder' field, the raw CAN signal value
285 /// will be passed to the decoder before publishing.
287 /// @param[in] signal - The details of the signal to decode and forward.
288 /// @param[in] message - The message with data to decode.
289 /// @param[out] send - An output parameter that will be flipped to false if the value could
292 /// The decoder returns an openxc_DynamicField, which may contain a number,
293 /// string or boolean.
295 openxc_DynamicField decoder_t::translate_signal(signal_t& signal, std::shared_ptr<message_t> message, bool* send)
297 if(!signal.get_message()->frame_layout_is_little())
299 signal.set_bit_position(converter_t::bit_position_swap(signal.get_bit_position(),signal.get_bit_size()));
301 // Must call the decoders every time, regardless of if we are going to
302 // decide to send the signal or not.
303 openxc_DynamicField decoded_value = decoder_t::decode_signal(signal,
306 signal.set_received(true);
307 signal.set_timestamp(message->get_timestamp());
308 signal.get_message()->set_last_value(message);
309 return decoded_value;
312 /// @brief Parse a signal from a CAN message and apply any required
313 /// transforations to get a human readable value.
315 /// If the signal_t has a non-NULL 'decoder' field, the raw CAN signal value
316 /// will be passed to the decoder before returning.
318 /// @param[in] signal - The details of the signal to decode and forward.
319 /// @param[in] message - The message with data to decode.
320 /// @param[out] send - An output parameter that will be flipped to false if the value could
323 /// @return The decoder returns an openxc_DynamicField, which may contain a number,
324 /// string or boolean. If 'send' is false, the return value is undefined.
326 openxc_DynamicField decoder_t::decode_signal( signal_t& signal, std::shared_ptr<message_t> message, bool* send)
328 signal_decoder decoder = signal.get_decoder() == nullptr ?
329 decode_noop : signal.get_decoder();
331 openxc_DynamicField decoded_value = decoder(signal,
333 return decoded_value;
337 /// @brief Decode the payload of an OBD-II PID.
339 /// This function matches the type signature for a DiagnosticResponse, so
340 /// it can be used as the decoder for a DiagnosticRequest. It returns the decoded
341 /// value of the PID, using the standard formulas (see
342 /// http://en.wikipedia.org/wiki/OBD-II_PIDs#Mode_01).
344 /// @param[in] response - the received DiagnosticResponse (the data is in response.payload,
345 /// a byte array). This is most often used when the byte order is
346 /// signiticant, i.e. with many OBD-II PID formulas.
347 /// @param[in] parsed_payload - the entire payload of the response parsed as an int.
349 /// @return Float decoded value.
351 float decoder_t::decode_obd2_response(const DiagnosticResponse* response, float parsed_payload)
353 return diagnostic_decode_obd2_pid(response);