Canbus help, filtering

monstermullet · July 11, 2024, 8:54pm

So i am just trying to read a specific message ID, change a few bytes and resend. I did that, but its way too slow responding since the lower IDs flood the system. So i need to filter the messages, and I did that. But I have no idea on how to combine the code so I am only seeing the filtered messages to change the bytes.

#include <mcp_can.h>
#include <SPI.h>

const uint32_t Ex_canID_rx = 0x02F83203;
const uint32_t Ex_canID_tx = 0x02F83204; //can id 0x0XXXXXXX
byte newValue[2] = {0x70, 0x17};

long unsigned int rxId;
unsigned char len = 0;
unsigned char rxBuf[8];
char msgString[128];                        // Array to store serial string

#define CAN0_INT 2                              // Set INT to pin 2
MCP_CAN CAN0(10);                               // Set CS to pin 10


void setup()
{
  Serial.begin(115200);

  // Initialize MCP2515 running at 16MHz with a baudrate of 500kb/s and the masks and filters disabled.
  if (CAN0.begin(MCP_ANY, CAN_500KBPS, MCP_16MHZ) == CAN_OK)
    Serial.println("MCP2515 Initialized Successfully!");
  else
    Serial.println("Error Initializing MCP2515...");

  CAN0.setMode(MCP_NORMAL);                     // Set operation mode to normal so the MCP2515 sends acks to received data.

  pinMode(CAN0_INT, INPUT);                            // Configuring pin for /INT input

  Serial.println("MCP2515 Library Receive Example...");
}

void loop()
{
  if (!digitalRead(CAN0_INT))                        // If CAN0_INT pin is low, read receive buffer
  {
    CAN0.readMsgBuf(&rxId, &len, rxBuf);      // Read data: len = data length, buf = data byte(s)

    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), len);
    else
      sprintf(msgString, "Standard ID: 0x%.3lX       DLC: %1d  Data:", rxId, len);

    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 < len; i++) {
        sprintf(msgString, " 0x%.2X", rxBuf[i]);
        Serial.print(msgString);
      }
    }
    Serial.println();

    if (rxId == Ex_canID_rx) {
      rxBuf[0] = newValue[0];
      rxBuf[1] = newValue[1];
      // send data:  ID = 0x0XXXXXXX, Extended CAN Frame, Data length = len, 'rxBuf' = array of data bytes to send
        byte sndStat = CAN0.sendMsgBuf(Ex_canID_tx, 1, len, rxBuf);
      if (sndStat == CAN_OK) {
        Serial.println("Message Sent Successfully!");
      } else {
        Serial.println("Error Sending Message...");
      }
    }
    
for reading and sending, but too slow

monstermullet · July 11, 2024, 8:56pm



#include <mcp_can.h>
#include <SPI.h>

long unsigned int rxId;
unsigned char len = 0;
unsigned char rxBuf[8];

MCP_CAN CAN0(10);                          // Set CS to pin 10

void setup()
{
  Serial.begin(115200);
  if(CAN0.begin(MCP_STDEXT, CAN_500KBPS, MCP_16MHZ) == CAN_OK) Serial.print("MCP2515 Init Okay!!\r\n");
  else Serial.print("MCP2515 Init Failed!!\r\n");
  pinMode(2, INPUT);                       // Setting pin 2 for /INT input


  CAN0.init_Mask(0,0,0x07FF0000);                // Init first mask...
  CAN0.init_Filt(0,0,0x02F832030);                // Init first filter...
  CAN0.init_Filt(1,0,0x02F832030);                // Init second filter...
  
  CAN0.init_Mask(1,0,0x07FF0000);                // Init second mask... 
  CAN0.init_Filt(2,0,0x02F832030);                // Init third filter...
  CAN0.init_Filt(3,0,0x02F832030);                // Init fourth filter...
  CAN0.init_Filt(4,0,0x02F832030);                // Init fifth filter...
  CAN0.init_Filt(5,0,0x02F832030);                // Init sixth filter...
  
  Serial.println("MCP2515 Library Mask & Filter Example...");
  CAN0.setMode(MCP_NORMAL);                // Change to normal mode to allow messages to be transmitted
}

void loop()
{
    if(!digitalRead(2))                    // If pin 2 is low, read receive buffer
    {
      CAN0.readMsgBuf(&rxId, &len, rxBuf); // Read data: len = data length, buf = data byte(s)
      Serial.print("ID: ");
      Serial.print(rxId, HEX);
      Serial.print(" Data: ");
      for(int i = 0; i<len; i++)           // Print each byte of the data
      {
        if(rxBuf[i] < 0x10)                // If data byte is less than 0x10, add a leading zero
        {
          Serial.print("0");
        }
        Serial.print(rxBuf[i], HEX);
        Serial.print(" ");
      }
      Serial.println();
    }
}

kolaha · July 11, 2024, 9:46pm

CAN0.init_Mask(0,1,0xFFFFFFFF);
CAN0.init_Mask(1,1,0xFFFFFFFF);

kolaha · July 11, 2024, 9:48pm

for(int i=0;i<6;i++) CAN0.init_Filt(i,1,0x02F83203);

monstermullet · July 11, 2024, 10:07pm

Do you mean put that code in the first code? Im not sure where I would put it on the first. They both work fine independently, I just need to filter, then receive that code...and mody and resend. The first code modifies and resends, the 2nd filters...but i need them to work together so it executes faster instead of waiting for that one ID to finally get through.

kolaha · July 11, 2024, 10:33pm

#include <mcp_can.h>
#include <SPI.h>

const uint32_t Ex_canID_rx = 0x02F83203;
const uint32_t Ex_canID_tx = 0x02F83204; //can id 0x0XXXXXXX
byte newValue[2] = {0x70, 0x17};

long unsigned int rxId;
unsigned char len = 0;
unsigned char rxBuf[8];
char msgString[128];                        // Array to store serial string

#define CAN0_INT 2                              // Set INT to pin 2
MCP_CAN CAN0(10);                               // Set CS to pin 10


void setup() {
  Serial.begin(115200);
  // Initialize MCP2515 running at 16MHz with a baudrate of 500kb/s and the masks and filters disabled.
  if (CAN0.begin(MCP_ANY, CAN_500KBPS, MCP_16MHZ) == CAN_OK)    Serial.println(" Initialized !");
  else    Serial.println("Error MCP2515...");

  CAN0.init_Mask(0, 1, 0xFFFFFFFF);
  CAN0.init_Mask(1, 1, 0xFFFFFFFF);
  for (int i = 0; i < 6; i++) CAN0.init_Filt(i, 1, 0x02F83203);

  CAN0.setMode(MCP_NORMAL);                     // Set operation mode to normal so the MCP2515 sends acks to received data.
  Serial.println("MCP2515 Library Receive Example...");
}

void loop() {
  if (!digitalRead(CAN0_INT))                        // If CAN0_INT pin is low, read receive buffer
  {
    CAN0.readMsgBuf(&rxId, &len, rxBuf);      // Read data: len = data length, buf = data byte(s)

    if ((rxId & 0x80000000))    // Determine if ID is standard (11 bits) or extended (29 bits)
      sprintf(msgString, "Extended ID: 0x%.8lX  DLC: %1d  Data:", (rxId & 0x1FFFFFFF), len);
    else      sprintf(msgString, "Standard ID: 0x%.3lX       DLC: %1d  Data:", rxId, len);
    Serial.print(msgString);

    if ((rxId & 0x40000000)) {  // Determine if message is a remote request frame.
      Serial.print(" REMOTE REQUEST FRAME");
    } else {
      for (byte i = 0; i < len; i++) {
        sprintf(msgString, " 0x%.2X", rxBuf[i]);
        Serial.print(msgString);
      }
    }
    Serial.println();

    if (rxId == Ex_canID_rx) {
      rxBuf[0] = newValue[0];
      rxBuf[1] = newValue[1];
      // send data:  ID = 0x0XXXXXXX, Extended CAN Frame, Data length = len, 'rxBuf' = array of data bytes to send
      byte sndStat = CAN0.sendMsgBuf(Ex_canID_tx, 1, len, rxBuf);
      if (sndStat == CAN_OK)Serial.println("Sent");
      else Serial.println("Error...");
    }
  }
}

monstermullet · July 11, 2024, 11:38pm

That didnt filter it at all, still same issue

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Canbus help, filtering

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