fscanf reads 0 from Arduino (connected to force/ pressure sensor) - despite non 0 values seen in Ardunio serial monitor

Hello everyone,

I am trying to read out from a force/ pressure sensor that is connected to an Ardunio Micro (connected by USB) into MATLAB.

When I use the Ardunio software and look in the serial monitor, pressing the force sensor shows values going up and down as they should:

However, when I try and read using matlab (using various read/ scan functions) I get 0's (even when pressing as above)

I tried changing the format of the output I was expecting to %s %s %s %d etc, but this did not work (and I think is not the correct format anyway). I tried various other things commented out below:

delete(instrfindall);

seriallist;

s1 = serial("/dev/tty.usbmodem1421");
s1.BaudRate = 9600; % rate of communication of serial monitor with
% s1.Terminator = 'CR/LF'; % might I need to change the terminator? It is
% default set as 'LF' (line feed?)

fopen(s1);
s1.status;

% Do I need to send it something?
% fprintf(s1, 'XXX');

for l = 1:50
    pause(.1)
    fscanf(s1)
    
    
    
    % no idea what the difference between these types of scan are
%     fgetl(s1)
%     fread(s1)
%     fgets(s1)
    
    % cant work out how to specify the output properly
    % fscanf(s1, '%s %s %s %d')
    % fscanf(s1, '%s %d')
    % fscanf(s1, 'Analog reading = %d')
end



fclose(s1)
delete(s1)
clear s1
clear all

As you can see I am a total novice... Any help would be very very very much appreciated, as I am supposed to have this up and running by Monday :s

Thank you all!

This is my Ardunio code in case helpful

Answer 1

[Vishnu Vardhan]

Hi Harriet,

I think you haven't tried using the function readVoltage function available in MATLAB. Why don't you give it a try.

Hope this helps https://in.mathworks.com/help/supportpkg/arduinoio/ref/readvoltage.html

Answer 2

[Harriet Dempsey-Jones]

Thank you Vishnu very much for your suggestion - just before I received it I tried removing the characters "Analog reading = " so Arduino just output the numbers, and that somehow helped!

Thank you once again for your help though! Will keep it in mind in future projects!