What is the best method to read an integer directly from a file (which ever file type is best)

Using Arduino Project Guidance
1

I have some values, between 0 and 255, stored on an sd (can be in any format), which correspond to rgbw color values. There are too many numbers for the on board arduino memory.

What is the go-to method to extract these numbers into integers?

Thank you

2

Hi,
Google;

arduino sd card tutorial

It will show you some tutorials that may help.

Thanks.. Tom.... :grinning: :+1: :coffee: :australia:

3 
byte RGBW[4];

  for (int i=0; i<4; i++)
   RGBW[i] = file.read();
4

Would that not read just 4 bytes? I guess the OP is asking how to read all numbers unless I have misunderstood something...

5

Your question is a bit vague. Are you concerned about changing bytes into integers? If so all you have to do is assign the byte to the integer like this:

byte RedByte = something read from memory
int RedInt = RedByte
6

Yes. It would read one RGBW value. Repeat for each set of values.

7

Thank you, do you know how to convert numbers in a text file (like 255) into single bytes (11111111)?

8

Ok thank you, this helps a lot

9

255 (decimal notation) and 11111111 (binary notation) and FF (hexadecimal notation) are all the same number. You can represent the same number in different forms, but the value is the same.

10

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