Using the command window as a serial monitor for arduino

I want to use the command window as a serial monitor to plot data sent by arduino or another device serially. I need to send some data to arduino too. I have the following code.

% lectura de puerto serial COM
clc;
clear;
close all;

%comandos de apertura del puerto serial
com_avr = serial('COM4',115200);
fopen(com_avr);

while(1)
    %para leer
    data = readline(com_avr); disp(data);   %para leer
    data = readline(com_avr); disp(data);
    
    str = input("Send to Arduino: ","s");
    val = sscanf(str, "%f");
    fprintf(com_avr, "%f", val);
    
    %muestra lo que se envio
    data = readline(com_avr); disp(data);
    
    %HERE MUST TO PLOT THE DATA
    while 1

    data = readline(com_avr);
  
        plot(x,data,'bd','LineWidth',2)

        axis([x-2 x 40 160])
        
        hold on
        drawnow
        
        x = x + 0.002;

    end
    
    %secuencia de comandos de salida
    if str == 'z'
        disp("exit")
        break;
    end
end

disp("closing communication...")
%finaliza la comunicacion serial y libera el puerto
close(com_avr);

What could I do to open a plot graph and plot the data sent from Arduino?

May you give me any sugestion to improve this code?

Answer 1

[Kothuri]

Hi Oscar,

In the above code, "while(1)" will cause an infinite loop and causes issue. And for plotting the data,

• you can predefine the "plot" object before the loop.
• Use "set()" to update data instead of replotting.

You can modify the above code as follows:

clc;
clear;
close all;

% Open Serial Port
com_avr = serial('COM4',115200);
fopen(com_avr);

% Initialize Plot
figure;
hold on;
grid on;
title("Real-time Serial Data Plot");
xlabel("Time (s)");
ylabel("Sensor Value");
xlim([0 10]);
ylim([40 160]);

% Plot Handle
h = plot(NaN, NaN, 'bd-', 'LineWidth', 2);
x = [];
y = [];
tic; % Start Timer

% Main Loop
while true
    % Read Data
    data = readline(com_avr);
    sensor_value = str2double(data);
    
    % Update Plot
    x = [x toc];
    y = [y sensor_value];
    
    set(h, 'XData', x, 'YData', y);
    xlim([max(0, x(end)-10) max(10, x(end))]); % Sliding window
    drawnow;
    
    % Send Data to Arduino
    str = input("Send to Arduino: ", "s");
    val = str2double(str);
    writeline(com_avr, num2str(val));
    
    % Check Exit Condition
    if str == "z"
        disp("Exit");
        break;
    end
end

% Close Serial Port
disp("Closing communication...");
clear com_avr;

The usage of "serial()" will be discontinued in future releases of MATLAB. Instead you can use "serialport()".

You can refer the below documentation links on "serial" and "set"

https://www.mathworks.com/help/releases/R2023b/matlab/ref/serial.fopen.html

https://www.mathworks.com/help/releases/R2023b/matlab/ref/set.html

[Oscar]

hello Kothuri, thanks for your comments, I have already solved my issues I use the serialport function and a more specific format. Greetings.

Answer 2

[MathWorks MATLAB Hardware Team]

Hello,

With the MATLAB Support Package for Arduino Hardware, you can efficiently read data from an Arduino.

If your board supports WiFi, you might also consider using its wireless capabilities to gather data.

Additionally, please let us know what specific data you are trying to read from the Arduino. Understanding your use case better will allow us to assist you more effectively.

Thank you,

MATLAB Hardware Team

MathWorks

[Oscar]

Thanks, I will try using the package. I still have to study it