Warning: Unsuccessful read: The specified amount of data was not returned within the Timeout period.. "

Hi,

I am sending data to Arduino serially, and I want it to read them and return them back to me.

The MATLAB code is

s=serial('COM4','BaudRate',9600);

set(s, 'TimeOut', 10);

fopen(s);

for i = 1:50

 fwrite(s, i, 'uint8');

 rx(i) = fread(s, 1);
end

fclose(s);

The error message I get is: " Warning: Unsuccessful read: The specified amount of data was not returned within the Timeout period.. "

I have read some possible causes for that problem such as the TimeOut period which I turned to 10. However I still get the same message. Can anyone help please?

Answer 1

[Arpita Agrawal]

Is there a code that is running on Arduino which is sending data over serial. If so, please share that as well. There is a possibility that the timeout occurs even before the hardware is sending the data.

[Angeliki Zafeiropoulou]

Hi and thank you for your answer. The arduino code is

char ibyte;

void setup()

{

Serial.begin(9600);

delay(2500);

}

void loop()

{

if(Serial.available()>0)

{

    ibyte=Serial.read(); 

    Serial.write(ibyte);

}
}

Answer 2

[Arpita Agrawal]

Hi Angeliki,

This implementation should work. Please verify that the Arduino board is able to send the data over Serial once using the 'DigitalReadSerial' example. If that is working well, probably you can try to increase the timeout value and check once. For further questions on this please contact MathWorks Technical Support.

Thanks Arpita

[Angeliki Zafeiropoulou]

Hi Arpita,

thank you for your answer. I set the timeout in Matlab to 20 by adding the command s.Timeout=20; but nothings changed. I read that the default value is 10.

Do I also have to change adduino's timeout and make it the same for example?

Thanks, Angeliki

[Arpita Agrawal]

Hi,

You can try configuring the timeout on MATLAB, if you are able to read the data over Arduino Serial Monitor using the Example.

Thanks Arpita