waitfor( ) isn't working for a SerialPort

Question

Gavin 2024-9-21

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2154560-waitfor-isn-t-working-for-a-serialport

评论： Gavin 2024-9-23

Seems simple my code does this to be sure everything has been processed from the USB port connected to an Arduino Pico.

if (app.PicoCom.NumBytesAvailable>0)
    PicoInput(app,app.PicoCom); % Call the callback 'by hand'
    waitfor(app.PicoCom,NumBytesAvailable,0);  % wait until it's REALLY done
end

I seem to need this because even though the trigger is "terminator" and call back has:

while (app.PicoCom.NumBytesAvailable>0)
     raw = readline(src);
     % Do the processing needed 
  end

sometimes data gets left in the buffer.

So here's the relevant help on waitfor():

waitfor(obj,propname,propvalue) specifies a value that the property must change to before execution can resume. If the specified property is already equal to propvalue, then waitfor returns immediately and execution resumes.

I assume that obj is the Serial Handle and I'm waiting for the property NumBytesAvailable to be 0

Here is what I get when it's run

Warning: Error executing listener callback for PostSet event on TotalBytesWritten

dynamic property in object of matlabshared.asyncio.internal.Channel class:

Unrecognized function or variable 'NumBytesAvailable'.

Error in MouseOdor20/RunTrial (line 419)

waitfor(app.PicoCom,NumBytesAvailable,0); % wait until it's REALLY done