F11_defaultStepAnswer.m

function [y,u,t] = F11_defaultStepAnswer(a,N,dT,p,m,saveFile)

% ******* PART A: Description of the different variables *******
%   output values:
%       - y:    vector containing level values
%       - u:    vector containing signal values
%       - t:    vector containing 't' samples (timepoints)
%   argument values:
%       - a:    arduino-object, accessed with: a = arduino_com('COMxx')
%       - N:    total samples
%       - dT:   samplingtime in seconds
%       - p:    inputsignal (tank1 or tank2)
%       - bv:   desired level for the regulation given in procent (0..100%)
%       - m:    signal strength (0-255) given in procent (0..100%)
% ***************************************************************


% *** PART C: Create and initialize different variables to save measurement results ***
y = zeros(1, N);        % vector with N nulls on a (1) row to be filled with measurements of the level in water tank 1 and 2
u(1:N) = 255*(m/100);   % limit the signal between 0-255 and signal strengt to be m%
t = (1:N)*dT;           % vector currently as a numbering of times from 1 to N times sampling time
ok=0;                   % used to detect too short sampling time
% *************************************************************************************


% if you want to get rid of strange values in the beginning
% make a "read analog" before the loop of analog inputs:
a.analogRead(p);


% ******* PART D: start regulating *******
for k=1:N % the loop will run N times, each time takes exactly dT seconds
    
    start = cputime; % start timer to measure exececution of one loop
    if (ok < 0)      % check if sampling time too short
        disp('samplingtime too short! Increase the value for dT');
        return
    end
    
    t(k)=k*dT; % update timevector
    
    % ---------------- Read and write from/to due --------------
    y(k) = a.analogRead(p); % measure water level in tank 1 or 2 depending on variable p
    disp("signal = " + u(k))
    analogWrite(a,u(k),'DAC1');
    % ----------------------------------------------------------
    
    
    % ------- online-plot START -------
    figure(1)
    plot(t,y,'k-',t,u,'m:');
    xlabel('samplingar (k)');
    if(p == 'a0')
        title('tank 1 stegsvar, level (y), signal (u)');
    else
        title('tank 2 stegsvar, level (y), signal (u)');
    end
    legend('y ', 'u ');
    % ------- online-plot END -------
    
    elapsed=cputime-start; % counts the amount of time in seconds
    ok=(dT-elapsed);       % saves the time margin in ok
    pause(ok);             % pauses remaining sampling time
    
end % -for (end of the samples)


% PART E: end experiment
analogWrite(a,0,'DAC1'); % turn pump off


% plot a final picture
figure(2)
if(p == 'a0')
    plot(t,y,'k-',t,u,'m:');
    xlabel('samplingar (k)')
    ylabel('level (y), signal (u)')
    title('Tank 1, stegsvar');
    legend('y ', 'u ')
else
    plot(t,y,'k-',t,u,'m:');
    xlabel('samplingar (k)')
    ylabel('level (y), signal (u)')
    title('Tank 2, stegsvar');
    legend('y ', 'u ')
end

saveas(figure(2), saveFile);

end