Undefined function 'voltageRead' for input arguments of type 'double'.

Question

Pinky Salvanera 2020-1-27

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/502184-undefined-function-voltageread-for-input-arguments-of-type-double

回答： Vimal Rathod 2020-1-30

I am trying to make a GUI using App Designer that reads and graphs the voltage sensed by my Arduino Uno. When I type on the Command Window the following syntax, I get results.

a=arduino('COM5','uno')
readVoltage(a,'A0')

But when I place the same syntax in a callback function in the App Designer, the error message "Undefined function 'voltageRead' for input arguments of type 'double'." appears. Below is part of my code in the App Designer.

 properties (Access = private)
     stop;
     done=0;
     a;
     h;
     s;
     SetPoint;
     luxvolt;
 end
    % Callbacks that handle component events
    methods (Access = private)
        % Code that executes after component creation
        function startupFcn(app)
            clear all;
            app.a = arduino('COM5','uno');
        end
                % Button pushed function: StartButton
        function StartButtonPushed(app, event)
            app.stop = false;
            
            
            
            app.h = animatedline(app.UIAxes);
            startTime = datetime('now');
            axis = gca;
            axis.YGrid ='on';
            axis.YLim = [0 5];
            
            while ~app.stop
                app.luxvolt = voltageRead(app.a, 'A4');
                
                %luxactual = (luxvolt - 1.4565) .* (2300 - 0) ./ (0.3519 - 1.4565) + 0;
                t = datetime('now') - startTime;
                addpoints(app.h,datenum(t),app.luxvolt);
                drawnow
                app.stop = app.done;
            end