plotting live data from a sensor

Hello,

I'm trying to plot a line graph of the live data from my sensor. However, when I run my code is does not display the line.

Thanks in advance

code:

clear all;
S = serialport('COM5',115200);

temp =[];
accx=[];
accy=[];
accz=[];
i = 0;

while true
    if S.NumBytesAvailable > 0
        data = readline(S); 
        temp = [str2double(split(data,','))]; 
        accx = [accx;temp(1)];
        accy = [accy;temp(2)];
        accz = [accz;temp(3)];
        plot(i,temp(1))
        i=i+1;
    end

end

Answer 1

[dpb]

You are plotting only one point at a time and without having executed a hold on instruction, each call to plot creates a new line object, deleting the previous. So, at most you would have a dot moving across the axis if the marker size were large enough to see it. To observe this, change your present plot() call to

plot(i,temp(1),'markersize',10)

To do this kind of thing you need to use hold on and update the XData,YData arrays instead, or use the new AnimatedLine feature. See

https://www.mathworks.com/help/matlab/creating_plots/animation-techniques-1.html

https://www.mathworks.com/help/matlab/creating_plots/line-animation-of-streaming-data.html

for details and examples.