i am using myrpi variable inside a while loop. i am gettng an error as undefine function or variable myrpi. code is " if isempty(bbox) disp('No one is Here turn off all connection')else disp('someone is here in the room')"Please help

code:

     if isempty(bbox)
      disp('No one is Here turn off all connection')

else
    disp('someone is here in the room turn on supply ')
    for i = 1:10
    writeDigitalPin(rpi, 4, 1);
    pause(0.5);
    writeDigitalPin(rpi, 4, 0);
    pause(0.5);
end

error:

Undefined function or variable 'rpi'.

Error in finalprogram1 (line 27)
    writeDigitalPin(rpi, 4, 1);

[Von Duesenberg]

You probably deleted the rpi object at some point (or failed to initialize it).

Answer 1

[Von Duesenberg]

I am not sure what the first clearvars is doing(the formatting of your code as it appears here probably lacks a number of end of lines characters) but the second one clears all variables except a variable called mypi... you called your raspi object rpi (not mypi), so it gets deleted by the call to clearvars. In other words, the following should do the trick:

clearvars -except rpi myCam flag

[sanjay singh]

thank you very much , after removing clearvars ,error was rectified.

Answer 2

[sanjay singh]

this is the whole program , i have initialized the rpi variable

%setup Raspberry pi
clearvars
rpi= raspi('192.168.43.142','pi','raspberry');
myCam= cameraboard(rpi,'Resolution','640x480');

%camera  snapshoot and detect face 
flag=1;
while flag
    clearvars -except mypi myCam flag
    mysnap= snapshot(myCam);
    imshow(mysnap);
    hold on
    faceDetector = vision.CascadeObjectDetector();
    bbox =step(faceDetector,mysnap);
    imageout=insertObjectAnnotation(mysnap,'rectangle',bbox,'face');
    imshow(imageout);
    title('Detected face');
    drawnow

      if isempty(bbox)
      disp('No one is Here turn off all connection')
      writeDigitalPin(rpi, 4, 0);
      pause(0.5);

else
    disp('someone is here in the room turn on supply ')
    for i = 1:10
    writeDigitalPin(rpi, 4, 1);
    pause(0.5);

end

end

end