no matching function for call to 'MCP_CAN::readMsgBuf(char*, unsigned char [8])'

Using Arduino Programming Questions
1

I don't understand why it gives such an error in the code.

#include <SPI.h> 
#include <mcp_can.h> 
#define SPI_CS_PIN 9
#define LED 8 
MCP_CAN CAN0(SPI_CS_PIN); 
void setup()
{
  Serial.begin(9600); 
  pinMode(LED,OUTPUT); 
  while (CAN_OK == CAN0.begin(MCP_ANY, CAN_500KBPS, MCP_8MHZ)) //can bus : baudrate = 500k 
  { 
    Serial.println("CAN BUS Shield Baslatmasi Basarili!");
  }
  Serial.println("CAN BUS Shield Baslatma Hatasi"); 
  Serial.println("CAN BUS Shield Tekrar Baslatiliyor…"); 
  delay(100);
}


void loop()
{ 
  unsigned char len = 0; 
  unsigned char buf[8]={0,0,0,0,0,0,0,0};
  if(CAN_MSGAVAIL == CAN0.checkReceive())
  { 
    CAN0.readMsgBuf(&len, buf);
    unsigned long canId = CAN0.getCanId(); 
    Serial.println("—————————–");
    Serial.print("Verici ID: 0x");
    Serial.println(canId, HEX);
    for(int i = 0; i<len; i++)
    {
      Serial.print(buf[i]); 
      Serial.print("\t");
      digitalWrite(LED, buf[0]);
      delay(100); 
    } 
    Serial.println(); 
  }
}

error messages

/tmp/332594481/sketch_may13a/sketch_may13a.ino: In function 'void loop()':

/tmp/332594481/sketch_may13a/sketch_may13a.ino:26:30: error: no matching function for call to 'MCP_CAN::readMsgBuf(char*, unsigned char [8])'

CAN0.readMsgBuf(&len, buf);

^

In file included from /tmp/332594481/sketch_may13a/sketch_may13a.ino:2:0:

/home/builder/opt/libraries/latest/mcp_can_1_5_0/mcp_can.h:119:11: note: candidate: byte MCP_CAN::readMsgBuf(long unsigned int*, byte*, byte*, byte*)

INT8U readMsgBuf(INT32U *id, INT8U *ext, INT8U *len, INT8U *buf); // Read message from receive buffer

^~~~~~~~~~

/home/builder/opt/libraries/latest/mcp_can_1_5_0/mcp_can.h:119:11: note: candidate expects 4 arguments, 2 provided

/home/builder/opt/libraries/latest/mcp_can_1_5_0/mcp_can.h:120:11: note: candidate: byte MCP_CAN::readMsgBuf(long unsigned int*, byte*, byte*)

INT8U readMsgBuf(INT32U *id, INT8U *len, INT8U *buf); // Read message from receive buffer

^~~~~~~~~~

/home/builder/opt/libraries/latest/mcp_can_1_5_0/mcp_can.h:120:11: note: candidate expects 3 arguments, 2 provided

/tmp/332594481/sketch_may13a/sketch_may13a.ino:27:32: error: 'class MCP_CAN' has no member named 'getCanId'; did you mean 'getGPI'?

unsigned long canId = CAN0.getCanId();

^~~~~~~~

getGPI

Error during build: exit status 1
2

The MCP_CAN class's readMsgBuf() function takes 3 or 4 parameters. From mcp_can.h:

    INT8U readMsgBuf(INT32U *id, INT8U *ext, INT8U *len, INT8U *buf);   // Read message from receive buffer
    INT8U readMsgBuf(INT32U *id, INT8U *len, INT8U *buf);               // Read message from receive buffer

The error message told you that.

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