CAN-bus module MCP2515 SPI 5V

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

const byte CAN_CS_PIN = 10;
const byte CAN_INT_PIN = 9;

MCP_CAN CAN(CAN_CS_PIN);

volatile bool canInterrupt = false;

void onCanInterrupt() {
  canInterrupt = true;
}

void setup() {
  Serial.begin(115200);
  while (!Serial) {
    ;
  }

  pinMode(CAN_INT_PIN, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(CAN_INT_PIN), onCanInterrupt, FALLING);

  Serial.println("Initializing MCP2515 CAN module...");

  // Common 5V MCP2515 modules often use an 8 MHz crystal.
  // If your board has a different oscillator, adjust MCP_8MHZ accordingly.
  byte initResult = CAN.begin(MCP_ANY, CAN_500KBPS, MCP_8MHZ);
  if (initResult == CAN_OK) {
    Serial.println("MCP2515 initialized successfully.");
  } else {
    Serial.print("MCP2515 initialization failed, error code: ");
    Serial.println(initResult);
    while (true) {
      delay(1000);
    }
  }

  CAN.setMode(MCP_NORMAL);
  Serial.println("CAN controller set to normal mode.");
  Serial.println("Waiting for CAN frames...");
}

void loop() {
  if (canInterrupt || CAN.checkReceive() == CAN_MSGAVAIL) {
    canInterrupt = false;

    unsigned long rxId = 0;
    byte len = 0;
    byte buf[8];

    // This mcp_can library version uses readMsgBuf() and readMsgBufID() is not available.
    if (CAN.readMsgBuf(&rxId, &len, buf) == CAN_OK) {
      Serial.print("Received CAN frame. ID=0x");
      Serial.print(rxId, HEX);
      Serial.print(" DLC=");
      Serial.print(len);
      Serial.print(" Data=");

      for (byte i = 0; i < len; i++) {
        if (buf[i] < 16) Serial.print('0');
        Serial.print(buf[i], HEX);
        if (i < len - 1) Serial.print(' ');
      }
      Serial.println();
    }
  }
}