possibility to log on an SD card about candrive HOT 2 OPEN

In order to make things more clear this is the code, the error is in the last if-else cycle; on the serial monitor i recive "error opening Datalog.txt"

#include <CAN.h>
#include <SPI.h>
#include <SD.h>

void setup() {
//setup CAN

Serial.begin(9600);
while (!Serial);

//setup parte CAN

Serial.println("CAN Receiver");

// start the CAN bus at 500 kbps
if (!CAN.begin(500E3)) {
Serial.println("Starting CAN failed!");
//while (1);
}
CAN.filter(0x518);

//setup SD
Serial.begin(9600);
while (!Serial) {
;
}

Serial.print("Initializing SD card...");

// see if the card is present and can be initialized:
if (!SD.begin(10)) {
Serial.println("Card failed, or not present");
// don't do anything more:
while (1);
}
Serial.println("card initialized.");

}

void loop() {

int packetSize = CAN.parsePacket(), i=0;
float Vlamb=0, lamb=0;
Vlamb=analogRead(A0);

float pack[8];

//Serial.print("packet with id 0x");
//Serial.print(CAN.packetId(), HEX);
//Serial.print(" and length ");
//Serial.println(packetSize);
//Serial.println();

//salvo i valori del pacchetto ricevuto nella matrice pack
      while (CAN.available()) {
    //Serial.print(CAN.read(), HEX);
    pack[i]=CAN.read();
    i=i+1;    
  }
Serial.println(); 
//stampo sul seriale i valori contenuti nel pacchetto ricevuto
for(i=0;i<8;i++) {
  Serial.print(pack[i]);
} 
Serial.println();

float rpm = ((pack[1] * 256.0) + pack[0]) / 4.0; //creo una variabile rpm che contiene rpm

Serial.print("Engine RPM = ");
Serial.println(rpm);
Serial.print("lamb = ");
lamb=Vlamb/3;
Serial.println(lamb);

// inizializzo stringa per raccogliere i dati

String dataString = "";

//popolo la stringa

int sensor = analogRead(A0);
dataString += String(sensor);

File dataFile = SD.open("datalog.txt", FILE_WRITE);

// controllo sul file
if (dataFile) {
dataFile.println(dataString);
dataFile.close();
// print to the serial port too:
Serial.println(dataString);
}

else {
Serial.println("error opening datalog.txt"); //here is it the error
}

delay(500);
}

from candrive.

Hello!
I'd suggest you to take a deep dive into SPI communication. You might need to change one or two things in the lower layers, but your setup (parallel MCP2515 and SDCard) is completely doable. You can just choose another pin as the SPI CS pin. That pin does nothing special, but goes low before the transmission, and goes high right after it. You can even control it yourself from the main logic. One thing to keep in mind: storing data to the SDCard will take some time, and meanwhile, you'll not be able to receive messages from the MCP2515 (because Arduino only has 1 SPI peripheral if I'm not mistaken).

from candrive.