Undefined function 'audioDeviceReader' for input arguments of type 'char'.

I get errors at line 49 and 62

classdef app_one < matlab.apps.AppBase
    % Properties that correspond to app components
    properties (Access = public)
        UIFigure         matlab.ui.Figure
        InstrumentLabel  matlab.ui.control.Label
        EditField3       matlab.ui.control.EditField
        ResetButton      matlab.ui.control.Button
        AnalyzeButton    matlab.ui.control.Button
        RecordButton     matlab.ui.control.Button
        UIAxes2          matlab.ui.control.UIAxes
        UIAxes           matlab.ui.control.UIAxes
    end
    
    properties (Access = private)
        
        fs % Description
        nob % Description
        noc % Description
        audio % Description
        y % Description
        t % Description
        nfft % Description
        f % Description
        ymax % Description
        f1 % Description
        f2 % Description
        xymax % Description
        xmax % Description
        val % Description
    end
    
    % Callbacks that handle component events
    methods (Access = private)
        % Button pushed function: RecordButton
        function RecordButtonPushed(app, event)
            app.EditField3.Value= '-';
            plot(app.UIAxes2,0,0);
            plot(app.UIAxes,0,0);
            
            app.RecordButton.BackgroundColor='g';
            
            app.fs=48000;
            app.nob=16;
            app.noc=2;
            app.audio=audioDeviceReader('SampleRate', app.fs, app.noc);
            app.y=record(app.audio, app.fs * 5)';
            
            app.RecordButton.BackgroundColor='w';
        end
        % Button pushed function: AnalyzeButton
        function AnalyzeButtonPushed(app, event)
            app.nfft=2^nextpow2(length(app.y));
            app.f=linspace(0,app.fs,app.nfft);
            app.y=abs(fft(app.y,app.nfft));
            % Find the highest peaks in the frequency spectrum
            [pks,locs] = findpeaks(app.y(2:app.nfft/2),'MinPeakHeight',0.1*max(app.y(2:app.nfft/2)),'MinPeakDistance',50);
            locs = locs + 1;
            % Match peak frequencies with known frequency ranges of different instruments
            instrument_names = {'Open Hi-Hat', 'Close Hi-Hat', 'Big Crash', 'Small Crash', 'Splash', 'Ride', 'Ride Bell', 'Floor Tom', 'High Tom', 'Low Tom', 'Bass Drum', 'Snare Drum'};
            instrument_freq_ranges = {[7633,7787], [11702,11938], [5038,5140], [3992,4072], [6020,6142], [3524,3596], [3693,3767], [75,77], [166,170], [109,113], [30,80], [400,3000]};
            detected_instruments = cell(1,length(locs)); % Preallocate cell array with fixed size
            for i = 1:length(locs)
                detected_instruments{i} = {};
                for j = 1:length(instrument_freq_ranges)
                    if locs(i) > instrument_freq_ranges{j}(1) && locs(i) < instrument_freq_ranges{j}(2)
                        detected_instruments{i} = instrument_names{j};
                    end
                end
            end
            % Display detected instruments
            if ~isempty(detected_instruments)
                app.EditField3.Value = strjoin(detected_instruments, ', ');
            else
                app.EditField3.Value = 'Unknown instrument';
            end
            % Plot frequency spectrum with peak frequencies marked
            plot(app.UIAxes2,app.f(2:app.nfft/2),app.y(2:app.nfft/2),'r');
            hold(app.UIAxes2, 'on');
            plot(app.UIAxes2,app.f(locs),pks,'*b');
            hold(app.UIAxes2, 'off');
        end
        % Button pushed function: ResetButton
        function ResetButtonPushed(app, event)
            
            app.EditField3.Value= '-';
            plot(app.UIAxes2,0,0);
            plot(app.UIAxes,0,0);
            clear sound;
            close all;
            
        end
    end
    % Component initialization
    methods (Access = private)
        % Create UIFigure and components
        function createComponents(app)
            % Create UIFigure and hide until all components are created
            app.UIFigure = uifigure('Visible', 'off');
            app.UIFigure.Position = [100 100 640 480];
            app.UIFigure.Name = 'MATLAB App';
            % Create UIAxes
            app.UIAxes = uiaxes(app.UIFigure);
            title(app.UIAxes, 'Time Domain')
            xlabel(app.UIAxes, 'Time')
            ylabel(app.UIAxes, 'Amplitude')
            zlabel(app.UIAxes, 'Z')
            app.UIAxes.Position = [1 153 313 328];
            % Create UIAxes2
            app.UIAxes2 = uiaxes(app.UIFigure);
            title(app.UIAxes2, 'Frequency Domain')
            xlabel(app.UIAxes2, 'Frequency')
            ylabel(app.UIAxes2, 'Amplitude')
            zlabel(app.UIAxes2, 'Z')
            app.UIAxes2.Position = [329 153 300 328];
            % Create RecordButton
            app.RecordButton = uibutton(app.UIFigure, 'push');
            app.RecordButton.ButtonPushedFcn = createCallbackFcn(app, @RecordButtonPushed, true);
            app.RecordButton.Position = [69 98 100 23];
            app.RecordButton.Text = 'Record';
            % Create AnalyzeButton
            app.AnalyzeButton = uibutton(app.UIFigure, 'push');
            app.AnalyzeButton.ButtonPushedFcn = createCallbackFcn(app, @AnalyzeButtonPushed, true);
            app.AnalyzeButton.Position = [259 97 100 23];
            app.AnalyzeButton.Text = 'Analyze';
            % Create ResetButton
            app.ResetButton = uibutton(app.UIFigure, 'push');
            app.ResetButton.ButtonPushedFcn = createCallbackFcn(app, @ResetButtonPushed, true);
            app.ResetButton.Position = [438 97 100 23];
            app.ResetButton.Text = 'Reset';
            % Create EditField3
            app.EditField3 = uieditfield(app.UIFigure, 'text');
            app.EditField3.Position = [282 38 100 22];
            % Create InstrumentLabel
            app.InstrumentLabel = uilabel(app.UIFigure);
            app.InstrumentLabel.Position = [301 59 62 22];
            app.InstrumentLabel.Text = 'Instrument';
            % Show the figure after all components are created
            app.UIFigure.Visible = 'on';
        end
    end
    % App creation and deletion
    methods (Access = public)
        % Construct app
        function app = app_one
            % Create UIFigure and components
            createComponents(app)
            % Register the app with App Designer
            registerApp(app, app.UIFigure)
            if nargout == 0
                clear app
            end
        end
        % Code that executes before app deletion
        function delete(app)
            % Delete UIFigure when app is deleted
            delete(app.UIFigure)
        end
    end
end

Answer 1

[Ajay Gajulapally]

Hi Michael,

Invalid argument syntax is being used on line 49

Consider changing the lines from

audioDeviceReader('SampleRate', app.fs, app.noc);

to

audioDeviceReader('SampleRate', app.fs,'NumChannels' app.noc);

if you want the number of channels to be of desired value.

Kindly ensure that "record" function being used at line 50 doesn't accept "audioDeviceReader" object with a time length, instead by each second. Then try to use a for loop to get number of seconds or try to use "audioRecorder" object instead of "audioDeviceReader" through which "record" function can take time as input

Refer to the following MATLAB documentation to know more:

Record from sound card - MATLAB - MathWorks India

Record audio to audiorecorder object - MATLAB - MathWorks India

Object for recording audio - MATLAB - MathWorks India