Spectrum analyser,Warning: The specified amount of data was not returned within the Timeout period for 'readline'. 'serialport' unable to read any data. For more information o

Hello everyone,

I'm currently working on my Arduino based project of real-time audio spectrum analyser. I wrote the code in Arduino IDE, which gets the data from sensor and sends data to Matlab in order like frequency1, magnitude1, frequency2, magnitude2,... Data from Arduino is sent in one line. The problem is, that I get the error:

Warning: The specified amount of data was not returned within the Timeout period for 'readline'.

'serialport' unable to read any data. For more information on possible reasons

Can anyone help? Here is the code:

% Serial port configuration
arduinoPort = 'COM3';
s = serialport(arduinoPort, 115200);
% Parameters
fs = 40000; 
measurementDuration = 3; 
frequencies = linspace(600, fs/2, fs/2);
magnitudes = zeros(1, fs/2);
start_time = tic;
% Loop to get data from Arduino
while toc(start_time) < measurementDuration
    
    data_str = readline(s);
    data_str = string(data_str);
    data = str2double(split(data_str, {',', ';'}));
    frequencies = data(1:2:end);
    magnitudes = data(2:2:end);
    pause(1/fs);
end
clear s;
% Plot the FFT graph
figure;
plot(frequencies, magnitudes, 'LineWidth', 2);
title('FFT - Magnitude');
xlabel('Frequency (Hz)');
ylabel('Magnitude');

Answer 1

[recent works]

1. Ensure Proper Serial Communication:

• Double-check the COM port (arduinoPort = 'COM3';). Make sure it matches the port where your Arduino is connected.
• Confirm that the baud rate (115200) in MATLAB matches the baud rate in your Arduino code (Serial.begin(115200);).

2. Stabilize Serial Communication:

• Add a delay in your Arduino code after sending the data to MATLAB to ensure that the data is fully transmitted before the next iteration of the loop.

delay(10); // or adjust the delay based on your system requirements

3. Check Arduino Code:

• Ensure that the Arduino code is consistently sending data in the expected format. Verify that the data is separated by commas and terminated with a semicolon.

4. Handle Errors:

• Implement error handling in your MATLAB code to gracefully handle situations where the expected data is not received within the timeout period.

try

data_str = readline(s);

catch

disp('Error reading data. Check the communication.');

continue; % Skip the current iteration and move to the next

end

5. Increase Timeout Period:

• You can increase the timeout period to give more time for data to be received.

configureTerminator(s, ";");

s.Timeout = 10; % or adjust the timeout based on your needs

5. Debugging:

• Print debug information in both the Arduino and MATLAB code to see the data being sent and received. This can help identify where the issue is occurring.