Re: Using the AVNA with the nanoVNA-saver control program

Bob Larkin

Hi Mike - Interesting errors. I do not see that under Linux. The n-saver program has a lot of warning/error/debug statements, that do not do anything on the graphical interface. Under Linux, these go as StdError to the "terminal", if I start the program from there. This has been quite helpfu at times. I don't know if that works under OS-X or not. You might see if that could help.

I don't see that error phrase in the n-saver code, so it must come from PySerial package. One thought is that it looks like a timeout error. The AVNA is not as fast as the nanoVNA in getting 101 points measured, and serial response from the AVNA is held up until that is finished. That was the issue that required the command buffering in the AVNA. The timeout amounts probably can be programed with a PySerial call. I'll do a bit more hunting on that one to see anything hops out that we could do.

By the way, the command buffering does not slow down the time for the AVNA to receive a command; it just is not acted on and responded to while the AVNA is measuring.

I'll look around in the program. Bob

On 2/13/20 10:16 AM, Mike Runyan via Groups.Io wrote:
I am on MacOS 10.15.3.  I don't think the serial problem is with your software.  Is shows up as a serial port and I can access it with many other programs.  The problem is with the way nanoVNA-saver software handles errors.  No matter the data you send, nanoV shouldn't crash.  If I have nothing connected to the AVNA input terminals, nanoV will crash after a bunch of (probably 101):
NanoVNASaver.SweepWorker - WARNING - Got a non-float data value: -34.626995 -46.589237 (-34.626995)
NanoVNASaver.Hardware - ERROR - Exception while reading data 1: Attempting to use a port that is not open
I forgot to mention that having the 50 ohm termination on during CALSAVE 1 did seem to make less noise as you mentioned.
Interesting you knew Phil Smith.  I don't think I'm that old at 64, but my first year of engineering in 1973 was the last year that slide rulers were required at University of Wisconsin - Madison engineering.  I still have it.
The PVC pipe inductor sounds interesting.

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