Writing binary data from sd card to the Serial port.

Using Arduino Storage
1

I have a csv file stored on an sd card (test.csv). I need to send the file to the serial port as binary and view the number of bytes written.

sample code:
//open the file for reading

myFile = SD.open("test.csv);
if (myFile) {

// read from the file

while (myFile.available()) {
Serial.write(myFile.read());
}
// close the file
myFile.close();
}

according the the reference available on the website, it says write() will return the number of bytes written, though reading that number is optional .

My problem is, how do i get the number of bytes written because my next application entirely depends on this number.

SD read _ write (1.15 KB)

2

according the the reference available on the website, it says write() will return the number of bytes written, though reading that number is optional .

My problem is, how do i get the number of bytes written because my next application entirely depends on this number.

"My problem is I need to know the number of bytes written." Then, discarding the output of Serial.write() is NOT optional, is it?

3 
int totalBytes = 0; // Start with zip

totalBytes += Serial.write(someStuff); // Add the number written this time.

It ain't rocket surgery.

4

I don't see why you have to count the characters written to the serial port, when you know how many are in the file.

You should be storing the myFile.read() value in a byte, and then Serial.write()ing that byte, anyway, to assure that only valid data is sent.

5

hdmafukidze:
thanks a lot i have tried that and it works for stings and integers (below 255) but it does not work for a scv file stored on an sd card.

Then use unsigned long or something else than an int.

Otherwise just use the SD library function to get the file size.

6

Thats the function i am looking for, if you know you can tell me.

You are already using it...

while (myFile.available())