2 #include <bitfield/bitfield.h>
3 #include <canutil/read.h>
9 #define ARBITRATION_ID_OFFSET 0x8
10 #define MODE_RESPONSE_OFFSET 0x40
11 #define NEGATIVE_RESPONSE_MODE 0x7f
12 #define MAX_DIAGNOSTIC_PAYLOAD_SIZE 6
13 #define MODE_BYTE_INDEX 0
14 #define PID_BYTE_INDEX 1
15 #define NEGATIVE_RESPONSE_MODE_INDEX 1
16 #define NEGATIVE_RESPONSE_NRC_INDEX 2
19 #define MAX(x, y) (((x) > (y)) ? (x) : (y))
22 DiagnosticShims diagnostic_init_shims(LogShim log,
23 SendCanMessageShim send_can_message,
24 SetTimerShim set_timer) {
25 DiagnosticShims shims = {
27 send_can_message: send_can_message,
33 static void setup_receive_handle(DiagnosticRequestHandle* handle) {
34 if(handle->request.arbitration_id == OBD2_FUNCTIONAL_BROADCAST_ID) {
37 response_id < OBD2_FUNCTIONAL_RESPONSE_COUNT; ++response_id) {
38 handle->isotp_receive_handles[response_id] = isotp_receive(
40 OBD2_FUNCTIONAL_RESPONSE_START + response_id,
43 handle->isotp_receive_handle_count = OBD2_FUNCTIONAL_RESPONSE_COUNT;
45 handle->isotp_receive_handle_count = 1;
46 handle->isotp_receive_handles[0] = isotp_receive(&handle->isotp_shims,
47 handle->request.arbitration_id + ARBITRATION_ID_OFFSET,
52 static uint16_t autoset_pid_length(uint8_t mode, uint16_t pid,
55 if(pid > 0xffff || mode > 10) {
64 DiagnosticRequestHandle diagnostic_request(DiagnosticShims* shims,
65 DiagnosticRequest* request, DiagnosticResponseReceived callback) {
66 DiagnosticRequestHandle handle = {
73 uint8_t payload[MAX_DIAGNOSTIC_PAYLOAD_SIZE] = {0};
74 payload[MODE_BYTE_INDEX] = request->mode;
75 if(request->has_pid) {
76 request->pid_length = autoset_pid_length(request->mode,
77 request->pid, request->pid_length);
78 handle.request.pid_length = request->pid_length;
79 set_bitfield(request->pid, PID_BYTE_INDEX * CHAR_BIT,
80 request->pid_length * CHAR_BIT, payload, sizeof(payload));
82 if(request->payload_length > 0) {
83 memcpy(&payload[PID_BYTE_INDEX + request->pid_length],
84 request->payload, request->payload_length);
87 handle.isotp_shims = isotp_init_shims(shims->log,
88 shims->send_can_message,
91 handle.isotp_send_handle = isotp_send(&handle.isotp_shims,
92 request->arbitration_id, payload,
93 1 + request->payload_length + request->pid_length,
95 if(shims->log != NULL) {
96 shims->log("Sending diagnostic request: arb_id: 0x%02x, mode: 0x%x, pid: 0x%x, payload: 0x%02x%02x%02x%02x%02x%02x%02x, size: %d\r\n",
97 request->arbitration_id,
107 request->payload_length);
110 setup_receive_handle(&handle);
112 // TODO notes on multi frame:
113 // TODO what are the timers for exactly?
115 // when sending multi frame, send 1 frame, wait for a response
116 // if it says send all, send all right away
117 // if it says flow control, set the time for the next send
118 // instead of creating a timer with an async callback, add a process_handle
119 // function that's called repeatedly in the main loop - if it's time to
120 // send, we do it. so there's a process_handle_send and receive_can_frame
121 // that are just called continuously from the main loop. it's a waste of a
122 // few cpu cycles but it may be more natural than callbacks.
124 // what woudl a timer callback look like...it would need to pass the handle
125 // and that's all. seems like a context void* would be able to capture all
126 // of the information but arg, memory allocation. look at how it's done in
127 // the other library again
132 DiagnosticRequestHandle diagnostic_request_pid(DiagnosticShims* shims,
133 DiagnosticPidRequestType pid_request_type, uint16_t arbitration_id,
134 uint16_t pid, DiagnosticResponseReceived callback) {
135 DiagnosticRequest request = {
136 arbitration_id: arbitration_id,
137 mode: pid_request_type == DIAGNOSTIC_STANDARD_PID ? 0x1 : 0x22,
142 return diagnostic_request(shims, &request, callback);
145 static bool handle_negative_response(IsoTpMessage* message,
146 DiagnosticResponse* response, DiagnosticShims* shims) {
147 bool response_was_negative = false;
148 if(response->mode == NEGATIVE_RESPONSE_MODE) {
149 response_was_negative = true;
150 if(message->size > NEGATIVE_RESPONSE_MODE_INDEX) {
151 response->mode = message->payload[NEGATIVE_RESPONSE_MODE_INDEX];
154 if(message->size > NEGATIVE_RESPONSE_NRC_INDEX) {
155 response->negative_response_code =
156 message->payload[NEGATIVE_RESPONSE_NRC_INDEX];
159 response->success = false;
160 response->completed = true;
162 return response_was_negative;
165 static bool handle_positive_response(DiagnosticRequestHandle* handle,
166 IsoTpMessage* message, DiagnosticResponse* response,
167 DiagnosticShims* shims) {
168 bool response_was_positive = false;
169 if(response->mode == handle->request.mode + MODE_RESPONSE_OFFSET) {
170 response_was_positive = true;
171 // hide the "response" version of the mode from the user
173 response->mode = handle->request.mode;
174 response->has_pid = false;
175 if(handle->request.has_pid && message->size > 1) {
176 response->has_pid = true;
177 if(handle->request.pid_length == 2) {
178 response->pid = get_bitfield(message->payload, message->size,
179 PID_BYTE_INDEX * CHAR_BIT, sizeof(uint16_t) * CHAR_BIT);
181 response->pid = message->payload[PID_BYTE_INDEX];
186 uint8_t payload_index = 1 + handle->request.pid_length;
187 response->payload_length = MAX(0, message->size - payload_index);
188 if(response->payload_length > 0) {
189 memcpy(response->payload, &message->payload[payload_index],
190 response->payload_length);
193 if((!handle->request.has_pid && !response->has_pid)
194 || response->pid == handle->request.pid) {
195 response->success = true;
196 response->completed = true;
198 response_was_positive = false;
201 return response_was_positive;
204 DiagnosticResponse diagnostic_receive_can_frame(DiagnosticShims* shims,
205 DiagnosticRequestHandle* handle, const uint16_t arbitration_id,
206 const uint8_t data[], const uint8_t size) {
208 DiagnosticResponse response = {
209 arbitration_id: arbitration_id,
214 if(!handle->isotp_send_handle.completed) {
215 isotp_continue_send(&handle->isotp_shims,
216 &handle->isotp_send_handle, arbitration_id, data, size);
219 for(i = 0; i < handle->isotp_receive_handle_count; ++i) {
220 IsoTpMessage message = isotp_continue_receive(&handle->isotp_shims,
221 &handle->isotp_receive_handles[i], arbitration_id, data,
224 if(message.completed) {
225 if(message.size > 0) {
226 response.mode = message.payload[0];
227 if(handle_negative_response(&message, &response, shims)) {
228 shims->log("Received a negative response to mode 0x%x on arb ID 0x%x",
229 response.mode, response.arbitration_id);
230 handle->success = true;
231 handle->completed = true;
232 } else if(handle_positive_response(handle, &message,
234 shims->log("Received a positive mode 0x%x response on arb ID 0x%x",
235 response.mode, response.arbitration_id);
236 handle->success = true;
237 handle->completed = true;
239 shims->log("Response was for a mode 0x%x request (pid 0x%x), not our mode 0x%x request (pid 0x%x)",
240 MAX(0, response.mode - MODE_RESPONSE_OFFSET),
241 response.pid, handle->request.mode,
242 handle->request.pid);
245 shims->log("Received an empty response on arb ID 0x%x",
246 response.arbitration_id);
249 if(handle->completed && handle->callback != NULL) {
250 handle->callback(&response);
260 float diagnostic_payload_to_float(const DiagnosticResponse* response) {
261 return bitfield_parse_float(response->payload,
262 response->payload_length, 0,
263 response->payload_length * CHAR_BIT, 1.0, 0);
268 * Functions pulled from http://en.wikipedia.org/wiki/OBD-II_PIDs#Mode_01
270 float diagnostic_decode_obd2_pid(const DiagnosticResponse* response) {
271 // handles on the single number values, not the bit encoded ones
272 switch(response->pid) {
274 return response->payload[0] * 3;
276 return (response->payload[0] * 256 + response->payload[1]) / 4.0;
280 return response->payload[0];
282 return (response->payload[0] * 256 + response->payload[1]) / 100.0;
290 return response->payload[0] * 100.0 / 255.0;
295 return response->payload[0] - 40;
297 return response->payload[0] - 125;