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,
90 handle.isotp_shims.frame_padding = !request->no_frame_padding;
92 handle.isotp_send_handle = isotp_send(&handle.isotp_shims,
93 request->arbitration_id, payload,
94 1 + request->payload_length + request->pid_length,
96 if(shims->log != NULL) {
97 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",
98 request->arbitration_id,
108 request->payload_length);
111 setup_receive_handle(&handle);
113 // TODO notes on multi frame:
114 // TODO what are the timers for exactly?
116 // when sending multi frame, send 1 frame, wait for a response
117 // if it says send all, send all right away
118 // if it says flow control, set the time for the next send
119 // instead of creating a timer with an async callback, add a process_handle
120 // function that's called repeatedly in the main loop - if it's time to
121 // send, we do it. so there's a process_handle_send and receive_can_frame
122 // that are just called continuously from the main loop. it's a waste of a
123 // few cpu cycles but it may be more natural than callbacks.
125 // what would a timer callback look like...it would need to pass the handle
126 // and that's all. seems like a context void* would be able to capture all
127 // of the information but arg, memory allocation. look at how it's done in
128 // the other library again
133 DiagnosticRequestHandle diagnostic_request_pid(DiagnosticShims* shims,
134 DiagnosticPidRequestType pid_request_type, uint16_t arbitration_id,
135 uint16_t pid, DiagnosticResponseReceived callback) {
136 DiagnosticRequest request = {
137 arbitration_id: arbitration_id,
138 mode: pid_request_type == DIAGNOSTIC_STANDARD_PID ? 0x1 : 0x22,
143 return diagnostic_request(shims, &request, callback);
146 static bool handle_negative_response(IsoTpMessage* message,
147 DiagnosticResponse* response, DiagnosticShims* shims) {
148 bool response_was_negative = false;
149 if(response->mode == NEGATIVE_RESPONSE_MODE) {
150 response_was_negative = true;
151 if(message->size > NEGATIVE_RESPONSE_MODE_INDEX) {
152 response->mode = message->payload[NEGATIVE_RESPONSE_MODE_INDEX];
155 if(message->size > NEGATIVE_RESPONSE_NRC_INDEX) {
156 response->negative_response_code =
157 message->payload[NEGATIVE_RESPONSE_NRC_INDEX];
160 response->success = false;
161 response->completed = true;
163 return response_was_negative;
166 static bool handle_positive_response(DiagnosticRequestHandle* handle,
167 IsoTpMessage* message, DiagnosticResponse* response,
168 DiagnosticShims* shims) {
169 bool response_was_positive = false;
170 if(response->mode == handle->request.mode + MODE_RESPONSE_OFFSET) {
171 response_was_positive = true;
172 // hide the "response" version of the mode from the user
174 response->mode = handle->request.mode;
175 response->has_pid = false;
176 if(handle->request.has_pid && message->size > 1) {
177 response->has_pid = true;
178 if(handle->request.pid_length == 2) {
179 response->pid = get_bitfield(message->payload, message->size,
180 PID_BYTE_INDEX * CHAR_BIT, sizeof(uint16_t) * CHAR_BIT);
182 response->pid = message->payload[PID_BYTE_INDEX];
187 uint8_t payload_index = 1 + handle->request.pid_length;
188 response->payload_length = MAX(0, message->size - payload_index);
189 if(response->payload_length > 0) {
190 memcpy(response->payload, &message->payload[payload_index],
191 response->payload_length);
194 if((!handle->request.has_pid && !response->has_pid)
195 || response->pid == handle->request.pid) {
196 response->success = true;
197 response->completed = true;
199 response_was_positive = false;
202 return response_was_positive;
205 DiagnosticResponse diagnostic_receive_can_frame(DiagnosticShims* shims,
206 DiagnosticRequestHandle* handle, const uint16_t arbitration_id,
207 const uint8_t data[], const uint8_t size) {
209 DiagnosticResponse response = {
210 arbitration_id: arbitration_id,
215 if(!handle->isotp_send_handle.completed) {
216 isotp_continue_send(&handle->isotp_shims,
217 &handle->isotp_send_handle, arbitration_id, data, size);
220 for(i = 0; i < handle->isotp_receive_handle_count; ++i) {
221 IsoTpMessage message = isotp_continue_receive(&handle->isotp_shims,
222 &handle->isotp_receive_handles[i], arbitration_id, data,
225 if(message.completed) {
226 if(message.size > 0) {
227 response.mode = message.payload[0];
228 if(handle_negative_response(&message, &response, shims)) {
229 shims->log("Received a negative response to mode 0x%x on arb ID 0x%x",
230 response.mode, response.arbitration_id);
231 handle->success = true;
232 handle->completed = true;
233 } else if(handle_positive_response(handle, &message,
235 shims->log("Received a positive mode 0x%x response on arb ID 0x%x",
236 response.mode, response.arbitration_id);
237 handle->success = true;
238 handle->completed = true;
240 shims->log("Response was for a mode 0x%x request (pid 0x%x), not our mode 0x%x request (pid 0x%x)",
241 MAX(0, response.mode - MODE_RESPONSE_OFFSET),
242 response.pid, handle->request.mode,
243 handle->request.pid);
246 shims->log("Received an empty response on arb ID 0x%x",
247 response.arbitration_id);
250 if(handle->completed && handle->callback != NULL) {
251 handle->callback(&response);
261 int diagnostic_payload_to_integer(const DiagnosticResponse* response) {
262 return get_bitfield(response->payload, response->payload_length, 0,
263 response->payload_length * CHAR_BIT);
266 float diagnostic_decode_obd2_pid(const DiagnosticResponse* response,
267 int parsed_payload) {
268 // handles on the single number values, not the bit encoded ones
269 switch(response->pid) {
271 return response->payload[0] * 3;
273 return (response->payload[0] * 256 + response->payload[1]) / 4.0;
277 return response->payload[0];
279 return (response->payload[0] * 256 + response->payload[1]) / 100.0;
287 return response->payload[0] * 100.0 / 255.0;
292 return response->payload[0] - 40;
294 return response->payload[0] - 125;