error in arduino object

error:Undefined function or variable 'ard'.

Error in bodekkealgo>automate (line 48)

fprintf(ard,'%d',index) %"here is where we send the position of image to arduino"

clc;
clear all;

CAMERA = videoinput('pointgrey', '1');%camera initialization
start(CAMERA);
ard = serial('COM3','BaudRate',9600);  %arduino initialization
fopen(ard);
pause(1);

for b = 1:8
    automate(CAMERA)
    pause(8)
end

fclose(ard)
stop(CAMERA);                      %stop camera acquisition

function[addition] = bodekke(imagename)  %bodekke function mathematics behind the autofocus detection
im = double(imread(imagename))
bd = [-1 0 1]
cbd = conv2(im,bd)
squaredcbd = cbd.^2
addition = sum(squaredcbd(:))
end
       
function automate(CAMERA)
for i = 1:30    %to capture images
    
filename = sprintf('testtry%02d.jpg',i);
img = im2double(getsnapshot(CAMERA));  %captures images
img = rgb2gray(img);
imwrite(img,filename)

end

D = 'C:\Users\PRL\Desktop\just';  %location where image  is stored
S = dir(fullfile(D,'*.jpg'));      
for k = 1:numel(S)              %applies bodekke to all images
    F = fullfile(D,S(k).name);
    addition(k) = bodekke(F);        %bodekke function call                                                                                
end
plot(addition);                     %plotting values just for our visual understanding
[m,index] = max(addition)
hold on
plot(index,m,'*')
hold off
title("bodekke with spot images")
fprintf(ard,'%d',index)            %"here is where we send the position of image to arduino"                                  



end

Answer 1

[Charan Jadigam]

Hi,

The serial object ‘ard’ is not defined in the scope of function ‘bodekke’ and so MATLAB is throwing an error. Try passing serial Arduino object to the function ‘bodekke’ and change the function declaration to add serial object ‘ard’ in argument list as shown below.

automate(CAMERA,ard);

function[addition] = bodekke(imagename,ard);

[barath V]

thanks