1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
|
/*
* 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 "../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<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<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<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<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<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.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<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<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);
}
|
