Matlab serial command to read binary data

I want to communicate with an Arduino board using Matlab through a serial port. The Arduino board will transmit 8 bytes of BINARY data every 20 ms once it receives a 1. The transmission will stop if the Arduino receives a 0.

The following commands in an m-file work as expected when I step through them in the debug mode. However, the transmission stopped immediately when I ran the m-file. The s.BytesAvailable is zero. It looks like the pause command has not properly executed. Why was wrong? How can I fix it? Thanks.

s = serial('COM15','BaudRate',115200);
fopen(s);
fwrite(s,1);           %ask Arduino to send data
tic;pause(3);toc       %wait for several data to arrive
fwrite(s,0);           %ask Arduino to stop sending data
fprintf(1,'%i\n\n',s.BytesAvailable)
fclose(s)

[Pritesh Shah]

Check following thing. 1. Did u connect to hardware to com15? (Go to device manager and click on port)

2. set(s, ’BaudRate’, 4800); % Set this Baud Rate

Go through following link may be useful: http://home.iitb.ac.in/~rahul./ITSP/serial_comm_matlab.pdf

[Jason Chen]

The code worked when I stepped through them in the debug mode. The com port and baud rate are not the problem. I think it has to do with the execution timing.

Answer 1

[Sean de Wolski]

You might be interested in doing this with the support package directly rather than using the serial port yourself

http://www.mathworks.com/matlabcentral/fileexchange/47522-matlab-support-package-for-arduino%C2%AE-hardware

[Jason Chen]

Mathworks states that the Matlab support package is not real time and the loop time can't be less than 40 ms (25 Hz). I'm using an Arduino for a real time application and like to transfer data to the computer to display later. I hope the serial data buffer can catch the data at faster rate.

I tried the Simulink Arduino support package. It doesn't work well in external mode either, especially for Due.