unable to establish serial connection between arduino ide and matlab

hi,i want the motor to rotate initially,then i have calculated the focus image index value in matlab,i want to send the value to arduino ide and the motor should rotate and come back to focus index value.

but its not happening

[barath V]

%matlab code
clc;
clear all;
CAMERA = videoinput('pointgrey', '1');
start(CAMERA);
pause(1);
a = serial('COM3','BaudRate',9600);
fopen(a);
pause(1);
fprintf(a,'%i',index)
fclose(a)


for i = 1:20
filename = sprintf('testtry%02d.jpg',i);
img = im2double(getsnapshot(CAMERA));
img = rgb2gray(img);
stop(CAMERA)
imwrite(img,filename)
end



D = 'C:\Users\PRL\Desktop\just';
S = dir(fullfile(D,'*.jpg')); % pattern to match filenames.
for k = 1:numel(S)
    F = fullfile(D,S(k).name);
    a(k) = bodekke(F);                                                                                       
end

plot(a);
[m,index] = max(a)
hold on
plot(index,m,'*')
hold off
title("bodekke with spot images")


function[addition] = bodekke(imagename)
im = double(imread(imagename))
bd = [-1 0 1]
cbd = conv2(im,bd)
squaredcbd = cbd.^2
addition = sum(squaredcbd(:))
end
        

[Walter Roberson]

fprintf(a,'%i',index)

index is not a defined variable at that point.

[barath V]

yes sir,i also get the same error i calculate the index value in matlab after i close the serial port,so only i get the error.

i tried to move the fprintf and fclose() command after second loop where i finished calculating index value,for that i get a different error.

[barath V]

any ideas or help please?

Answer 1

[Nikhil Sonavane]

You may refer to the following documentation for more information-

• Read Streaming Data from Arduino Using Serial Port Communication