How to make a re-connection for Bluetooth communication?

Question

SungCheol Hong 2023-3-15

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1929305-how-to-make-a-re-connection-for-bluetooth-communication

回答： Dinesh 2023-4-5

nrf_plotter_sh.mlapp

Hello! I am currently developing a MATLAB APP Designer application that connects to a Bluetooth device and plots the data received from the device's analog inputs. The code for the application is mostly functional, but I am facing an issue where the application does not attempt to reconnect to the Bluetooth device if the connection is lost between the application and the device.

To address this issue, I have implemented a code to check the connection status and attempt to reconnect to the device in case of a disconnection. The code snippet is provided below.

Is there something that I made a mistake about?

It still does not make a reconnection once after losing its connection.

It would be really appreciated if there is someone who can give me a clue about this.

I will attach an app also for just in case.

Thankyou very much.

    
    methods (Access = private)
        function onDataRecieve(app, src)
            
            app.timer = timer('ExecutionMode', 'fixedRate', 'Period', 1, 'TimerFcn', @(~,~)checkDataReceived(app));
            app.ble = ble(app.BLEAddressEditField.Value);
            start(app.timer);
            
            function checkDataReceived(app)
                % Get the timestamp of the last received packet
                lastTimestamp = datetime(app.bleData.timestamp(app.bleData.count, :));
                
                % Check if the last packet was received more than 1 second ago
                if (datetime('now') - lastTimestamp) > seconds(1)
                    % Stop the timer
                    stop(app.timer);
                    
                    % Disconnect from the BLE device
                    disconnect(app.ble);
                    
                    % Reconnect to the BLE device
                    app.ble = ble(app.BLEAddressEditField.Value);
                    start(app.timer);
                end
            end
            %
            [data, timestamp] = read(src,'oldest');
            timestamp.Format = 'yyyy-MM-DD hh:mm:ss.SSS';
            count = app.bleData.count+1;
            
            if count >= size(app.bleData.rx,1)
                app.bleData.rx(count + 100,app.bleData.MTUlength) = 0;
                aa = strings([100,1]);
                app.bleData.timestamp = [app.bleData.timestamp; aa];
            end
            
            if app.bleData.leadigZeroCut==true %
                app.bleData.rx(count,:) = data(2:end);
            else
                app.bleData.rx(count,:) = data;
            end
            
            
            app.bleData.count = count;
            app.RecievedPacketsEditField.Value = count;
            app.bleData.timestamp(count,1) = timestamp;
            data_1 = app.bleData.rx(count,:);
            app.ChannelPktSizeEditField.Value = app.bleData.MTUlength/app.ChannelCountSpinner.Value;
            switch app.ChannelCountSpinner.Value
                case 1
                    app.bleData.channel0(count,:) = data_1;
                case 2
                    app.bleData.channel0(count,:) = data_1(2:2:end);
                    app.bleData.channel1(count,:) = data_1(1:2:end);
                case 3
                    app.bleData.channel0(count,:) = data_1(3:3:end);
                    app.bleData.channel1(count,:) = data_1(2:3:end);
                    app.bleData.channel2(count,:) = data_1(1:3:end);
                case 4
                    app.bleData.channel0(count,:) = data_1(4:4:end);
                    app.bleData.channel1(count,:) = data_1(3:4:end);
                    app.bleData.channel2(count,:) = data_1(2:4:end);
                    app.bleData.channel3(count,:) = data_1(1:4:end);
            end 
            if mod(count,app.axes.updateSpeed) == 0
                app.updateFigure;
                if count > app.XCountSpinner.Value %originally 2
                    if strcmp(app.AutoUpdatePlotSwitch.Value, 'On')
                        xlim(app.UIAxes, [(count-app.XCountSpinner.Value)*app.bleData.MTUlength, count*app.bleData.MTUlength]/app.ChannelCountSpinner.Value);%originally 2
                        xlim(app.UIAxes_2, [(count-app.XCountSpinner.Value)*app.bleData.MTUlength, count*app.bleData.MTUlength]/app.ChannelCountSpinner.Value); %originally 2
                        xlim(app.UIAxes_3, [(count-app.XCountSpinner.Value)*app.bleData.MTUlength, count*app.bleData.MTUlength]/app.ChannelCountSpinner.Value);%originally 2
                        xlim(app.UIAxes_4, [(count-app.XCountSpinner.Value)*app.bleData.MTUlength, count*app.bleData.MTUlength]/app.ChannelCountSpinner.Value); %originally 2
                    end
                end
            end
            
        end
        
        %Rest of the code for plotting~~~
    end
       

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Dinesh 2023-4-5

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1929305-how-to-make-a-re-connection-for-bluetooth-communication#answer_1209169

Hello.

The issue with your code may be related to the fact that you are starting the timer inside the "onDataRecieve" function. This function will be called every time a new data packet is received. So, this means you will be creating multiple timers, which might interfere with each other.

I suggest moving the timer creation and start outside of the "onDataRecieve" function, so that you only create and start the timer once. You can do this in the "startupFcn" function or in any other function where you initialize your app.