Hi everybody,
I'm writing because I can't read messages from my OBD2 CAN-Bus socket in the car.
Thanks to ELM327 OBDII, I could check the protocol used by ECM: CAN Extended 29 bits,500kb ISO 15765-4.
(link: https://www.amazon.it/Ellenne-DIAGNOSTICA-Scanner-Bluetooth-Compatibile/dp/B08954ZRK7/ref=asc_df_B08954ZRK7/?tag=googshopit-21&linkCode=df0&hvadid=459268562771&hvpos=&hvnetw=g&hvrand=16439785881293494442&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1008141&hvtargid=pla-1157134366989&psc=1)
SW_CONFIG:
I attached the code and libraries used.
I set the correct standard for MCP2515-TJA1050 (as in code, defined standard 0 means functional_id request 0x18DB33F1, --> I saw in the original code the functional id was 0x98DB33F1
but is it correct?)
HW_CONFIG:
I connected MCP2515 in this way:
MCP2515 CAN H --> pin 6 obd2 socket
MCP2515 CAN L --> pin 14 obd2 socket
obd2 socket pin 4 --> GND arduino UNO board
obd2 socket pin 5 --> GND arduino UNO board
MCP2515 Vcc --> 5V arduino UNO board
MCP2515 GND --> GND arduino UNO board
MCP2515 CS --> pin 9 arduino UNO board
MCP2515 INT --> pin 2 arduino UNO board
MCP2515 SCK --> pin 13 arduino UNO board
MCP2515 SO --> pin 12 arduino UNO board
MCP2515 is terminated with a jumper on J1 (120 Ohm, as specification describes).
MCP2515 is configured for 500 kb and 8Mhz.
#include <mcp_can_dfs.h>
/* CAN OBD & UDS Simple PID Request
*
* Currently requests PID 0x00 at a 1 second interval and
* displays all received CAN traffic to the terminal at 115200.
*
* Written By: Cory J. Fowler April 5th, 2017
*
* (Disclaimer: Standard IDs are currently UNTESTED against a vehicle)
*
*/
#include <mcp_can.h>
#include <SPI.h>
#define standard 0
// 7E0/8 = Engine ECM
// 7E1/9 = Transmission ECM
#if standard == 1
#define LISTEN_ID 0x7EA
#define REPLY_ID 0x7E0
#define FUNCTIONAL_ID 0x7DF
#else
#define LISTEN_ID 0x18DAF101
#define REPLY_ID 0x18DA01F1
#define FUNCTIONAL_ID 0x18DB33F1
#endif
// CAN TX Variables
unsigned long prevTx = 0;
unsigned int invlTx = 1000;
byte txData[] = {0x02,0x01,0x00,0x55,0x55,0x55,0x55,0x55};
// CAN RX Variables
unsigned long rxID;
byte dlc;
byte rxBuf[8];
char msgString[128]; // Array to store serial string
// CAN Interrupt and Chip Select Pins
#define CAN0_INT 2 /* Set INT to pin 2 (This rarely changes) */
MCP_CAN CAN0(9); /* Set CS to pin 9 (Old shields use pin 10) */
void setup(){
Serial.begin(115200);
while(!Serial);
// Initialize MCP2515 running at 16MHz with a baudrate of 500kb/s and the masks and filters disabled.
if(CAN0.begin(MCP_STDEXT, CAN_500KBPS, MCP_8MHZ) == CAN_OK)
Serial.println("MCP2515 Initialized Successfully!");
else{
Serial.println("Error Initializing MCP2515... Permanent failure! Check your code & connections");
while(1);
}
//
// Allow all Standard IDs
CAN0.init_Mask(0,0x00000000); // Init first mask...
CAN0.init_Filt(0,0x00000000); // Init first filter...
CAN0.init_Filt(1,0x00000000); // Init second filter...
// Allow all Extended IDs
CAN0.init_Mask(1,0x80000000); // Init second mask...
CAN0.init_Filt(2,0x80000000); // Init third filter...
CAN0.init_Filt(3,0x80000000); // Init fourth filter...
CAN0.init_Filt(4,0x80000000); // Init fifth filter...
CAN0.init_Filt(5,0x80000000); // Init sixth filter...
//#if standard == 1
// // Standard ID Filters
// CAN0.init_Mask(0,0x7F00000); // Init first mask...
// CAN0.init_Filt(0,0x7DF0000); // Init first filter...
// CAN0.init_Filt(1,0x7E10000); // Init second filter...
//
// CAN0.init_Mask(1,0x7F00000); // Init second mask...
// CAN0.init_Filt(2,0x7DF0000); // Init third filter...
// CAN0.init_Filt(3,0x7E10000); // Init fourth filter...
// CAN0.init_Filt(4,0x7DF0000); // Init fifth filter...
// CAN0.init_Filt(5,0x7E10000); // Init sixth filter...
//
//#else
// // Extended ID Filters
// CAN0.init_Mask(0,0x90FF0000); // Init first mask...
// CAN0.init_Filt(0,0x90DA0000); // Init first filter...
// CAN0.init_Filt(1,0x90DB0000); // Init second filter...
//
// CAN0.init_Mask(1,0x90FF0000); // Init second mask...
// CAN0.init_Filt(2,0x90DA0000); // Init third filter...
// CAN0.init_Filt(3,0x90DB0000); // Init fourth filter...
// CAN0.init_Filt(4,0x90DA0000); // Init fifth filter...
// CAN0.init_Filt(5,0x90DB0000); // Init sixth filter...
//#endif
CAN0.setMode(MCP_NORMAL); // Set operation mode to normal so the MCP2515 sends acks to received data.
// Having problems? ======================================================
// If you are not receiving any messages, uncomment the setMode line below
// to test the wiring between the Ardunio and the protocol controller.
// The message that this sketch sends should be instantly received.
// ========================================================================
//CAN0.setMode(MCP_LOOPBACK);
pinMode(CAN0_INT, INPUT); // Configuring pin for /INT input
Serial.println("Simple CAN OBD-II PID Request");
}
void loop(){
if(!digitalRead(CAN0_INT)){ // If CAN0_INT pin is low, read receive buffer
CAN0.readMsgBuf(&rxID, &dlc, rxBuf); // Get CAN data
// Display received CAN data as we receive it.
if((rxID & 0x80000000) == 0x80000000) // Determine if ID is standard (11 bits) or extended (29 bits)
sprintf(msgString, "Extended ID: 0x%.8lX DLC: %1d Data:", (rxID & 0x1FFFFFFF), dlc);
else
sprintf(msgString, "Standard ID: 0x%.3lX DLC: %1d Data:", rxID, dlc);
Serial.print(msgString);
if((rxID & 0x40000000) == 0x40000000){ // Determine if message is a remote request frame.
sprintf(msgString, " REMOTE REQUEST FRAME");
Serial.print(msgString);
} else {
for(byte i = 0; i<dlc; i++){
sprintf(msgString, " 0x%.2X", rxBuf[i]);
Serial.print(msgString);
}
}
Serial.println();
}
/* Every 1000ms (One Second) send a request for PID 00 *
* This PID responds back with 4 data bytes indicating the PIDs *
* between 0x01 and 0x20 that are supported by the vehicle. */
if((millis() - prevTx) >= invlTx){
prevTx = millis();
if(CAN0.sendMsgBuf(FUNCTIONAL_ID ,8, txData) == CAN_OK){
Serial.println("Message Sent Successfully!");
} else {
Serial.println("Error Sending Message...");
}
}
}The code works properly in simulation mode (I used a CAN device VN1610 using a IG_Node).
But I noticed, after CAN pin 6-14 to the OBD2 socket connection, several errors appear on the dashboard.
The errors disappear after a KL15 key-cycle.
The errors change everytime, it seems to dipend on the functional_ID is used.
Could someone help me please? Just any advice to understand why it doesn't work.
Thank you so much in advance