Reading two voltages from arduino.

Hello, I'm trying to read two voltage using the fscanf function to read two voltages in arduino which display like the following using the arduino monitor serial I get: 1022.00,1022.00 1023.00,1022.00 1023.00,1022.00 etc.. Yet when I try to read the two values I use the following code: a=fscanf(s,'%d,%d'); v1(i)=a(1)*5/1024; % 5/1024 is a constant v2(i)=a(2)*5/1024; % 5/1024 is a constant

but for a(2) in the v2(i) line It mentions me that: ??? Attempted to access a(2); index out of bounds because numel(a)=1. giving me the Idea that a is only taking one of the two voltages, so I was wondering how to make the a take the two values?

Answer 1

[Geoff]

Probably because you're asking it to read integers (%d), not floats (%f). Make that change.

Also, beware of MatLab's fscanf behaviour. If you only want to read one pair of numbers, you have to do:

fscanf(s, '%f,%f', 1);

[Tomas]

oh you are right about the float situation now it seems to work fine and it graphs well! thanks a lot!

Answer 2

[Edmond]

Hi, I have the same problem now. It's the first time I am using arduino and Matlab together. I change the integer for floats and there is no response. Sometimes the program is running but giving the wrong values and something not.

--->Attempted to access a(2); index out of bounds because numel(a)=1.

Error in Morduino (line 41) v2(i)=a(2)*5/1024;