close all;
clear all;
clc;
delete(instrfindall);  %close all opened serial ports that are not in use

s1 = serial('COM3');   %define serial port
s1.BaudRate=9600;      %define baud rate
fopen(s1);             %open serial port

plot(0,0)              %empty plot
hold on                %
grid on                %
xlabel('Time, [s]', 'FontName', 'Times New Roman', 'FontSize', 14);
ylabel('Distance [cm]','FontName', 'Times New Roman', 'FontSize', 14);
title('Ultrasonic Ranging Module HC-SR04, taking readings every 0.1 second', 'FontName', 'Times New Roman', 'FontSize', 14)

data = [];             %empty vectors for data storage
ix = [];               %

%distance = 0;

flushinput(s1);        %clear any stored data on the serial port

%30 minutes, ploting data every half second
%writing the received data into the empty vector
%plotting the data in realtime

for i= 1 : 3600*5
    data(i) = str2double(fscanf(s1));
    ix(i) = i/10;
    plot(ix, data, 'r', 'LineWidth', 1.5)
    axis([i/10-8.5 i/10+1.5 0 300])
    pause(0.1)
end;

fclose(s1);            %close serial port