Writing float as binary on SD card

Projects Programming
1

Hi All,

I am trying to write float numbers to an SD card in a binary format, but the SD library write() function
only supports byte, char and string formats.

Is there a simple way of converting float numbers to binary? I have tried using unions in the form below:

SdFat sd; //file system object
SdFile dataFile; //log file

void writePoint(); {

union{byte uBytes[4]; float uFloat;} dataPoint;

dataFile.open("datalog.bin", FILE_WRITE);
dataPoint.uFloat = 3.14;
dataFile.write(dataPoint.uBytes, 4);
dataFile.close();

}

For some reason this code keeps crashing. Any suggestions on a solution? Thanks!

2

Do you actually check to see if the file was opened successfully? Some SD cards are pretty finicky. You probably need to check the return value from open() to make sure.

3 
void writePoint(); {

Why is that ; there?