USB Serial Driver - Suggestions

[RakshanPremsagar]

Hi,
I have connected the embedded device via the USB port. In my YAML file, I have defined the configuration as
resources: USBSerialPort: match: ID_SERIAL_SHORT: 'XXXX' ID_USB_INTERFACE_NUM: 'XX' speed: 115200

I have written a pytest case, where data is read from the serial driver.
I have a conftest.py which does the following :

`

`

and I have a method which captures serial responses :

But I observe an inconsistent error ( not always the case) which says :

pexpect.exceptions.TIMEOUT: Timeout of 1.00 seconds exceeded or connection closed by peer

I used a retry mechanism, to execute the function 5 more times when an exception occurs, but still the same response. How to counter this? Any suggestions could be really helpful

[Emantor]

Are you sure that your device connected via serial is returning bytes in all cases? The call to read() on the SerialDriver directly maps to the underlying pyserial library, so if the device sends bytes they should be received here.

[RakshanPremsagar]

@Emantor yes I do. As I mentioned, this is not an everytime occurrence. But it's annoying to see it sometimes. Any alternatives you could suggest?

[Emantor]

Hm, I am not sure which part of the chain is causing this issue. Could you try writting a script with pyserial alone and without labgrid? This way we can isolate whether this is a bug in labgrids SerialDriver or an issue with pyserial itself.