Reading from serial port

Question

Akash 2011-2-3

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/758-reading-from-serial-port

Hi, I need to interface MATLAB with a COM port to read data from sensors. Here is my MATLAB code.

    s = serial('COM5');
    s.BaudRate = 115200;
    fopen(s);
    tic
    for i = 1:25
        an = fscanf(s,'%c');
    end
    toc
    fclose(s);

I have used "tic" "toc" for measuring execution time to read 25 values and its almost 5 seconds. This is pretty slow. 115200 is the max Baud Rate.

Is there a better/faster way to read from a serial port???

Thanks all

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Answer 1

Ankit Desai 2011-2-9

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https://ww2.mathworks.cn/matlabcentral/answers/758-reading-from-serial-port#answer_1583

在 MATLAB Online 中打开

Akash,

You might be getting the data slowly. The delay might be caused by fscanf waiting for data to be available. As listed in the documentation - fscanf waits for data to be available until a timeout occurs.

You can confirm the same by checking that there 50 bytes available (25 bytes for character values + 25 bytes for terminator values) before you call the fscanf(s) in the for loop.

You can do so by checking the BytesAvailable field of the object.

s.BytesAvailable

I tried the same and was able to do so in < 1 second.

Hope this helps,

-Ankit