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 uint32_t bit_size = signal.get_bit_size();
40 uint32_t bit_position = signal.get_bit_position();
42 int new_start_byte = 0;
44 int new_start_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++)
51 data_signal.push_back(data[i]);
54 uint8_t new_bit_size = 0;
58 AFB_ERROR("Error signal %s to long bit size",signal.get_name().c_str());
62 new_bit_size = (uint8_t) bit_size;
65 uint8_t bit_offset = 0;
66 if(new_start_bit > 255)
68 AFB_ERROR("Too long signal offset %d", new_start_bit);
72 bit_offset = (uint8_t) new_start_bit;
77 if(data_signal.size() > 65535)
79 AFB_ERROR("Too long data signal %s",signal.get_name().c_str());
83 length = (uint16_t) data_signal.size();
86 return bitfield_parse_float(data_signal.data(), length,
87 bit_offset, new_bit_size, signal.get_factor(),
92 /// @brief Decode and return string bytes (hex) for a CAN signal's.
94 /// This is an implementation of the Signal type signature, and can be
95 /// used directly in the signal_t.decoder field.
97 /// @param[in] signal - The details of the signal.
98 /// @param[in] message - The message with data to decode.
99 /// @param[out] send - An output argument that will be set to false if the value should
100 /// not be sent for any reason.
102 /// @return Returns a DynamicField with a string value of bytes (hex)
104 openxc_DynamicField decoder_t::decode_bytes(signal_t& signal, std::shared_ptr<message_t> message, bool* send)
107 openxc_DynamicField decoded_value;
108 std::vector<uint8_t> data = message->get_data_vector();
109 uint32_t length = message->get_length();
110 uint32_t bit_position = signal.get_bit_position();
111 uint32_t bit_size = signal.get_bit_size();
112 std::vector<uint8_t> new_data = std::vector<uint8_t>();
113 new_data.reserve(bit_size << 3);
115 int new_start_byte = 0;
116 int new_end_byte = 0;
117 int new_start_bit = 0;
120 converter_t::signal_to_bits_bytes(bit_position, bit_size, new_start_byte, new_end_byte, new_start_bit, new_end_bit);
122 if(new_end_byte >= length)
124 new_end_byte = length-1;
127 if(new_start_byte >= length)
129 AFB_ERROR("Error in description of signals");
130 return decoded_value;
133 uint8_t first = data[new_start_byte];
135 for(i=new_start_bit;i<8;i++)
137 mask_first = mask_first | (1 << i);
140 uint8_t mask_first_v = 0;
143 AFB_ERROR("Error mask decode bytes");
147 mask_first_v = (uint8_t)mask_first;
150 data[new_start_byte]=first&mask_first_v;
152 uint8_t last = data[new_end_byte];
154 for(i=0;i<=new_end_bit;i++)
156 mask_last = mask_last | (1 << (7-i));
159 uint8_t mask_last_v = 0;
162 AFB_ERROR("Error mask decode bytes");
166 mask_last_v = (uint8_t)mask_last;
169 data[new_end_byte]=last&mask_last_v;
172 for(i=new_start_byte;i<=new_end_byte;i++)
174 new_data.push_back(data[i]);
177 decoded_value = build_DynamicField(new_data);
179 return decoded_value;
182 /// @brief Wraps a raw CAN signal value in a DynamicField without modification.
184 /// This is an implementation of the Signal type signature, and can be
185 /// used directly in the signal_t.decoder field.
187 /// @param[in] signal - The details of the signal that contains the state mapping.
188 /// @param[in] message - The message with data to decode.
189 /// @param[out] send - An output argument that will be set to false if the value should
190 /// not be sent for any reason.
192 /// @return Returns a DynamicField with the original, unmodified raw CAN signal value as
193 /// its numeric value. The 'send' argument will not be modified as this decoder
196 openxc_DynamicField decoder_t::decode_noop(signal_t& signal, std::shared_ptr<message_t> message, bool* send)
198 float value = decoder_t::parse_signal_bitfield(signal, message);
199 AFB_DEBUG("Decoded message from parse_signal_bitfield: %f", value);
200 openxc_DynamicField decoded_value = build_DynamicField(value);
202 // Don't send if they is no changes
203 if ((signal.get_last_value() == value && !signal.get_send_same()) || !*send )
207 signal.set_last_value(value);
209 return decoded_value;
211 /// @brief Coerces a numerical value to a boolean.
213 /// This is an implementation of the Signal type signature, and can be
214 /// used directly in the signal_t.decoder field.
216 /// @param[in] signal - The details of the signal that contains the state mapping.
217 /// @param[in] message - The message with data to decode.
218 /// @param[out] send - An output argument that will be set to false if the value should
219 /// not be sent for any reason.
221 /// @return Returns a DynamicField with a boolean value of false if the raw signal value
222 /// is 0.0, otherwise true. The 'send' argument will not be modified as this
223 /// decoder always succeeds.
225 openxc_DynamicField decoder_t::decode_boolean(signal_t& signal, std::shared_ptr<message_t> message, bool* send)
227 float value = decoder_t::parse_signal_bitfield(signal, message);
228 AFB_DEBUG("Decoded message from parse_signal_bitfield: %f", value);
229 openxc_DynamicField decoded_value = build_DynamicField(value == 0.0 ? false : true);
231 // Don't send if they is no changes
232 if ((signal.get_last_value() == value && !signal.get_send_same()) || !*send )
236 signal.set_last_value(value);
239 return decoded_value;
241 /// @brief Update the metadata for a signal and the newly received value.
243 /// This is an implementation of the Signal type signature, and can be
244 /// used directly in the signal_t.decoder field.
246 /// This function always flips 'send' to false.
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 - This output argument will always be set to false, so the caller will
251 /// know not to publish this value to the pipeline.
253 /// @return Return value is undefined.
255 openxc_DynamicField decoder_t::decode_ignore(signal_t& signal, std::shared_ptr<message_t> message, bool* send)
257 float value = decoder_t::parse_signal_bitfield(signal, message);
261 signal.set_last_value(value);
262 openxc_DynamicField decoded_value;
264 return decoded_value;
267 /// @brief Find and return the corresponding string state for a CAN signal's
268 /// raw integer value.
270 /// This is an implementation of the Signal type signature, and can be
271 /// used directly in the signal_t.decoder field.
273 /// @param[in] signal - The details of the signal that contains the state mapping.
274 /// @param[in] message - The message with data to decode.
275 /// @param[out] send - An output argument that will be set to false if the value should
276 /// not be sent for any reason.
278 /// @return Returns a DynamicField with a string value if a matching state is found in
279 /// the signal. If an equivalent isn't found, send is sent to false and the
280 /// return value is undefined.
282 openxc_DynamicField decoder_t::decode_state(signal_t& signal, std::shared_ptr<message_t> message, bool* send)
284 float value = decoder_t::parse_signal_bitfield(signal, message);
285 AFB_DEBUG("Decoded message from parse_signal_bitfield: %f", value);
286 const std::string signal_state = signal.get_states((uint8_t)value);
287 openxc_DynamicField decoded_value = build_DynamicField(signal_state);
288 if(signal_state.size() <= 0)
291 AFB_ERROR("No state found with index: %d", (int)value);
294 // Don't send if they is no changes
295 if ((signal.get_last_value() == value && !signal.get_send_same()) || !*send )
299 signal.set_last_value(value);
302 return decoded_value;
306 /// @brief Parse a signal from a CAN message, apply any required transforations
307 /// to get a human readable value and public the result to the pipeline.
309 /// If the signal_t has a non-NULL 'decoder' field, the raw CAN signal value
310 /// will be passed to the decoder before publishing.
312 /// @param[in] signal - The details of the signal to decode and forward.
313 /// @param[in] message - The message with data to decode.
314 /// @param[out] send - An output parameter that will be flipped to false if the value could
317 /// The decoder returns an openxc_DynamicField, which may contain a number,
318 /// string or boolean.
320 openxc_DynamicField decoder_t::translate_signal(signal_t& signal, std::shared_ptr<message_t> message, bool* send)
323 // Must call the decoders every time, regardless of if we are going to
324 // decide to send the signal or not.
325 openxc_DynamicField decoded_value = decoder_t::decode_signal(signal,
328 signal.set_received(true);
329 signal.set_timestamp(message->get_timestamp());
330 signal.get_message()->set_last_value(message);
331 return decoded_value;
334 /// @brief Parse a signal from a CAN message and apply any required
335 /// transforations to get a human readable value.
337 /// If the signal_t has a non-NULL 'decoder' field, the raw CAN signal value
338 /// will be passed to the decoder before returning.
340 /// @param[in] signal - The details of the signal to decode and forward.
341 /// @param[in] message - The message with data to decode.
342 /// @param[out] send - An output parameter that will be flipped to false if the value could
345 /// @return The decoder returns an openxc_DynamicField, which may contain a number,
346 /// string or boolean. If 'send' is false, the return value is undefined.
348 openxc_DynamicField decoder_t::decode_signal( signal_t& signal, std::shared_ptr<message_t> message, bool* send)
350 signal_decoder decoder = signal.get_decoder() == nullptr ?
351 decode_noop : signal.get_decoder();
353 openxc_DynamicField decoded_value = decoder(signal,
355 return decoded_value;
359 /// @brief Decode the payload of an OBD-II PID.
361 /// This function matches the type signature for a DiagnosticResponse, so
362 /// it can be used as the decoder for a DiagnosticRequest. It returns the decoded
363 /// value of the PID, using the standard formulas (see
364 /// http://en.wikipedia.org/wiki/OBD-II_PIDs#Mode_01).
366 /// @param[in] response - the received DiagnosticResponse (the data is in response.payload,
367 /// a byte array). This is most often used when the byte order is
368 /// signiticant, i.e. with many OBD-II PID formulas.
369 /// @param[in] parsed_payload - the entire payload of the response parsed as an int.
371 /// @return Float decoded value.
373 float decoder_t::decode_obd2_response(const DiagnosticResponse* response, float parsed_payload)
375 return diagnostic_decode_obd2_pid(response);