Two graphs at the same time

PLEASE HELP

Hello,

I have this code that is used with arduino package

the code will be used to get data from two sensors:

1. load cell that measures load
2. displacement sensor that measures displacement

problems:

1. this code is showing two graphs but only one graph has labels
2. only one graph is showing data results

this is the code: (please note that i'm new to MATLAB and coding in general)

clear
clc
a=arduino('com3','Uno')
loadcell=addon(a,'ExampleAddon/HX711',{'D2','D3'})
plotTitle1 = 'Load VS Time';
xLabel1 = 'Elapsed Time (s)';
yLabel1 = 'Load (KN)';
legend1 = 'Load Cell 1'
plotTitle2 = 'Displacement VS Time';
xLabel2 = 'Elapsed Time (s)';
yLabel2 = 'Displacement (mm)';
legend2 = 'Displacement Sensor 1'
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0 1 1]);
yMax1  = 10000000
yMin1  = 0
yMax2  = 10000000
yMin2  = 0
plotGrid = 'on';
min1 = 0;
max1 = 10000;
min2 = 0;
max2 = 10000;
delay = .001;
time = 0;
data1 = 0;
data11 = 0;
data12 = 0;
data2 = 0;
data21 = 0;
data22 = 0;
count = 0;
subplot(2,4,1)
plotGraph1 = plot(time,data1,'-r')
subplot(2,4,2)
plotGraph2 = plot(time,data2,'-r')
hold on
title(plotTitle1,'FontSize',5);
xlabel(xLabel1,'FontSize',5);
ylabel(yLabel1,'FontSize',5);
axis([yMin1 yMax1 min1 max1]);
title(plotTitle2,'FontSize',5);
xlabel(xLabel2,'FontSize',5);
ylabel(yLabel2,'FontSize',5);
axis([yMin2 yMax2 min2 max2]);
grid(plotGrid);
tic
figure (1)
while  ishandle(plotGraph1)
        dat1 = read_HX711(loadcell)-1940.225269
        count = count + 1;
        time(count) = toc;
        data1(count) = dat1(1);
        
        set(plotGraph1,'XData',time,'YData',data1);
        axis([0 time(count) min1 max1]);
        pause(delay);
end
hold on
figure (2)
while  ishandle(plotGraph2)
        dat2 = readVoltage(a,'A0')*80
        count = count + 1;
        time(count) = toc;
        data2(count) = dat2(1);
        set(plotGraph2,'XData',time,'YData',data2);
        axis([0 time(count) min2 max2]);
        pause(delay);
end 
hold off
delete(a);
disp('Plot Closed and arduino object has been deleted');

Answer 1

[darova]

Try to use subplot() each time you want plot or modify something in figure

subplot(2,4,1)
plotGraph1 = plot(time,data1,'-r')
title(plotTitle1,'FontSize',5);
xlabel(xLabel1,'FontSize',5);
ylabel(yLabel1,'FontSize',5);
axis([yMin1 yMax1 min1 max1]);

subplot(2,4,2)
plotGraph2 = plot(time,data2,'-r')
title(plotTitle2,'FontSize',5);
xlabel(xLabel2,'FontSize',5);
ylabel(yLabel2,'FontSize',5);
axis([yMin2 yMax2 min2 max2]);
grid(plotGrid);
tic
% figure (1)                % already created with "plotGraph1 = plot(time,data1,'-r')"
subplot(2,4,1), hold on
while  ishandle(plotGraph1)
        dat1 = read_HX711(loadcell)-1940.225269
        count = count + 1;
        time(count) = toc;
        data1(count) = dat1(1);
%         set(plotGraph1,'XData',time,'YData',data1);
        plot(time, data1, '-r')
        axis([0 time(count) min1 max1]);
        pause(delay);
end
hold off
subplot(2,4,1), hold on
% figure (2)                % already created with "plotGraph2 = plot(time,data2,'-r')"
while  ishandle(plotGraph2)
        dat2 = readVoltage(a,'A0')*80
        count = count + 1;
        time(count) = toc;
        data2(count) = dat2(1);
%         set(plotGraph2,'XData',time,'YData',data2);
        plot(time, data2, '-r')
        axis([0 time(count) min2 max2]);
        pause(delay);
end 
hold off

[Ameen Mouazzen]

Thank you very much.

But it didn't work :(

This way both graphs are showing no results

[darova]

What about while loop? This condition is awlays met

plotGraph1 = plot(time,data1,'-r')
while  ishandle(plotGraph1)
    % what is going here never ends
end

[Ameen Mouazzen]

Can you please show me how to write it on my script?

I'm very new to MATLAB and I just need it to work for my civil engineering graduation project as soon as possible.

Thank you so much for the reply.

[darova]

subplot(2,4,1), hold on
subplot(2,4,2), hold on
tic
n = 2000;                                    % 2000 measurements
[time, data1, data2] = deal( zeros(1,n) );
for count = 1:n
    dat1 = read_HX711(loadcell)-1940.225269
    dat2 = readVoltage(a,'A0')*80
    time(count) = toc;
    data1(count) = dat1(1);
    data2(count) = dat2(1);        
    subplot(2,4,1)
    plot(time(count),data1(count),'.b');
%     axis([0 time(count) min1 max1]);
    subplot(2,4,2)
    plot(time(count),data2(count),'.r');
%     axis([0 time(count) min2 max2]);
    drawnow
    pause(delay);
end 
subplot(2,4,1), hold off
subplot(2,4,2), hold off

You said it didn't work. Is there any error? What does MATLAB say?

[Ameen Mouazzen]

Hello,

Thank you very much for your help.

For the first time, the two graphs are working simultaneously.

Me and my colleagues appreciate your help very much.

Two problems left:

1. both graphs are showing the data results in dots not lines ( we need them to be as lines)
2. when I stop the code from runnung the graph window keeps opening again

clear
clc

a=arduino('com3','Uno')
loadcell=addon(a,'ExampleAddon/HX711',{'D2','D3'})

plotTitle1 = 'Load VS Time';
xLabel1 = 'Elapsed Time (s)';
yLabel1 = 'Load (KN)';
legend1 = 'Load Cell 1'

plotTitle2 = 'Displacement VS Time';
xLabel2 = 'Elapsed Time (s)';
yLabel2 = 'Displacement (mm)';
legend2 = 'Displacement Sensor 1'

set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0 1 1]);

yMax1  = 10000000
yMin1  = 0
yMax2  = 10000000
yMin2  = 0

plotGrid = 'on';

min1 = -10000000000;
max1 = 10000000000;
min2 = -10000000000;
max2 = 10000000000;

delay = .001;

time = 0;

data1 = 0;
data11 = 0;
data12 = 0;

data2 = 0;
data21 = 0;
data22 = 0;

count = 0;

subplot(2,4,1), hold on
subplot(2,4,2), hold on
tic
n = 2000;                                    % 2000 measurements
[time, data1, data2] = deal( zeros(1,n) );
for count = 1:n
    dat1 = read_HX711(loadcell)-1940.225269
    dat2 = readVoltage(a,'A0')*80
    time(count) = toc;
    data1(count) = dat1(1);
    data2(count) = dat2(1);        
    subplot(2,4,1)
    plot(time(count),data1(count),'.b');
%     axis([0 time(count) min1 max1]);
    subplot(2,4,2)
    plot(time(count),data2(count),'.r');
%     axis([0 time(count) min2 max2]);
    drawnow
    pause(delay);
end 
subplot(2,4,1), hold off
subplot(2,4,2), hold off

delete(a);
disp('Plot Closed and arduino object has been deleted');

[darova]

To draw a line "plot" needs at least 2 points ( plot([x1 x2], [y1 y2]) )

subplot(2,4,1), hold on
subplot(2,4,2), hold on
tic
n = 2000;                                    % 2000 measurements
[time, data1, data2] = deal( zeros(1,n) );
time(1) = 0;
data1(1) = read_HX711(loadcell)-1940.225269
data2(2) = readVoltage(a,'A0')*80
for count = 2:n
    dat1 = read_HX711(loadcell)-1940.225269
    dat2 = readVoltage(a,'A0')*80
    time(count) = toc;
    data1(count) = dat1(1);
    data2(count) = dat2(1);        
    subplot(2,4,1)
    plot([time(count-1) time(count)], ...
         [data1(count-1) data1(count)],'.-b');
%     axis([0 time(count) min1 max1]);
    subplot(2,4,2)
    plot([time(count-1) time(count)], ...
         [data2(count-1) data2(count)],'.-r');
%     axis([0 time(count) min2 max2]);
    drawnow
    pause(delay);
end 
subplot(2,4,1), hold off
subplot(2,4,2), hold off
delete(a);
disp('Plot Closed and arduino object has been deleted');

Which way do you stop the code? Closing figure or script is not enough

Use Ctrl+C

Answer 2

[Ameen Mouazzen]

Thank you very much for the reply.

Everything now is working correctly.

The Ctrl+C command worked.

New problems:

• the graphs are showing no lables at all
• the graphs take only half the screen. is there a way to make them bigger?
• no gridlines shown in the graphs

clear
clc
a=arduino('com3','Uno')
loadcell=addon(a,'ExampleAddon/HX711',{'D2','D3'})
plotTitle1 = 'Load VS Time';
xLabel1 = 'Elapsed Time (s)';
yLabel1 = 'Load (KN)';
legend1 = 'Load Cell 1'
plotTitle2 = 'Displacement VS Time';
xLabel2 = 'Elapsed Time (s)';
yLabel2 = 'Displacement (mm)';
legend2 = 'Displacement Sensor 1'
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0 1 1]);
yMax1  = 10000000
yMin1  = 0
yMax2  = 10000000
yMin2  = 0
plotGrid = 'on';
min1 = -10000000000;
max1 = 10000000000;
min2 = -10000000000;
max2 = 10000000000;
delay = .001;
time = 0;
data1 = 0;
data11 = 0;
data12 = 0;
data2 = 0;
data21 = 0;
data22 = 0;
count = 0;
subplot(2,4,1), hold on
subplot(2,4,2), hold on
tic
n = 2000;                                    % 2000 measurements
[time, data1, data2] = deal( zeros(1,n) );
time(1) = 0;
data1(1) = read_HX711(loadcell)
data2(2) = readVoltage(a,'A0')
for count = 2:n
    dat1 = read_HX711(loadcell)-1940.225269
    dat2 = readVoltage(a,'A0')*80
    time(count) = toc;
    data1(count) = dat1(1);
    data2(count) = dat2(1);        
    subplot(2,4,1)
    plot([time(count-1) time(count)], ...
         [data1(count-1) data1(count)],'.-b');
%     axis([0 time(count) min1 max1]);
    subplot(2,4,2)
    plot([time(count-1) time(count)], ...
         [data2(count-1) data2(count)],'.-r');
%     axis([0 time(count) min2 max2]);
    drawnow
    pause(delay);
end 
subplot(2,4,1), hold off
subplot(2,4,2), hold off
delete(a);
disp('Plot Closed and arduino object has been deleted');

[darova]

Why did you remove that part with (xlabel(xLabel1,'FontSize',5);) ?

Maybe you can plot your data in separate figures instead of subplot:

h1 = figure;                    % create figure for data1
xlabel(xLabel1,'FontSize',5);   % add x label
% set figure size
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0 1 1]);

h2 = figure;                    % create figure for data2
xlabel(xLabel2,'FontSize',5);   % add x label
% set figure size
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0 1 1]);

figure(h1)                     % set active figure "h1" (data1)
plot(time, data1, '.-r')       % draw something 
hold on                        % retain current plot for adding new data

figure(h2)                     % set active figure "h2" (data2)
plot(time, data2, '.-b')       % draw something
hold on                        % retain current plot for adding new data

figure(h1)                     % set active figure "h1" (data1)
plot([0 1], [1 1], '.-r')      % add some data

figure(h2)                     % set active figure "h2" (data2)
plot([1 2], [2 1], '.-b')      % add some data

figure(h1), hold off           % set hold state to "off"
figure(h2), hold off

Learn what each operation does, understand logic. Can't write good code without holding entire picture in your head

[Ameen Mouazzen]

Yes I agree,

But I'm studying civil engineering which has nothing to do with MATLAB. I started using MATLAB about 1 week ago. Before that time I didn't know anything about coding. And I've learnt a lot of things during this time. But my only concern is to make it work even If I didn't know how it works. becuase it is not related to my major. My graduation project submission is next week. Thats why I really don't have the time to learn everything before I start. But I'm trying my best.

Anyways, thank you very much for your help.

[Ameen Mouazzen]

I found a problem in factoring (dat1)

dat1 should be substracted from 8411800 and then multiplied by 0.000462214

as follows:

(dat1-8411800)*0.000462214

the brackets are important

have been trying for an hour

here is the script

clear
clc

a=arduino('com3','Uno')
loadcell=addon(a,'ExampleAddon/HX711',{'D2','D3'})

plotTitle1 = 'Load VS Time';
xLabel1 = 'Elapsed Time (s)';
yLabel1 = 'Load (KN)';
legend1 = 'Load Cell'

plotTitle2 = 'Displacement VS Time';
xLabel2 = 'Elapsed Time (s)';
yLabel2 = 'Displacement (mm)';
legend2 = 'Displacement Sensor'


set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0 2 2]);

yMax1  = 10000000
yMin1  = 0
yMax2  = 10000000
yMin2  = 0
plotGrid = 'on';

min1 = 0;
max1 = 1000;
min2 = 0;
max2 = 1000;

delay = .001;
time = 0;
data1 = 0;
data11 = 0;
data12 = 0;
data2 = 0;
data21 = 0;
data22 = 0;
count = 0;

subplot(1,2,1), hold on
subplot(1,2,2), hold on

tic

n = 2000;
[time, data1, data2] = deal( zeros(1,n) );
time(1) = 0;

data1(1) = read_HX711(loadcell)
data2(2) = readVoltage(a,'A0')

for count = 2:n
    
    dat1 = read_HX711(loadcell)-8411800*(-0.000462214)
    dat2 = readVoltage(a,'A0')*90
    time(count) = toc;
    data1(count) = dat1(1);
    data2(count) = dat2(1);        
    subplot(1,2,1)
    xlabel(xLabel1,'FontSize',15);
    ylabel(yLabel1,'FontSize',15);
    plot([time(count-1) time(count)], ...
         [data1(count-1) data1(count)],'.-b');
    subplot(1,2,2)
    xlabel(xLabel2,'FontSize',15);
    ylabel(yLabel2,'FontSize',15);
    plot([time(count-1) time(count)], ...
         [data2(count-1) data2(count)],'.-r');
    drawnow
    pause(delay);
end 

subplot(1,2,1), hold off
subplot(1,2,2), hold off

delete(a);
disp('Plot Closed and arduino object has been deleted');