Controlling device via Serial commands

[Ho-Ro]

Coming from NanoVNA-Saver/nanovna-saver#676

@krupis wrote:

However, I am not fully understanding how to use nanovna_capture.py and nanovna_snp.py ...

[Ho-Ro]

Let's follow up the discussion here, because it is not nanovna-saver related.

I did a quick step-by-step test on a windows machine as normal user, fresh python install (3.11.2), no device connected:

c:\Users\...\projects\NanoVNA\nanovna-tools>python nanovna_command.py
Traceback (most recent call last):
  File "c:\Users\...\projects\NanoVNA\nanovna-tools\nanovna_command.py", line 16, in <module>
    import serial
ModuleNotFoundError: No module named 'serial'

Ok, pyserial is missing:

pip install pyserial
Collecting pyserial
  Downloading pyserial-3.5-py2.py3-none-any.whl (90 kB)
     ---------------------------------------- 90.6/90.6 kB 737.1 kB/s eta 0:00:00
Installing collected packages: pyserial
Successfully installed pyserial-3.5

[notice] A new release of pip available: 22.3.1 -> 23.3
[notice] To update, run: python.exe -m pip install --upgrade pip

Next try w/o a device connected:

c:\Users\...\projects\NanoVNA\nanovna-tools>python nanovna_command.py
Traceback (most recent call last):
  File "c:\Users\...\projects\NanoVNA\nanovna-tools\nanovna_command.py", line 46, in <module>
    nanodevice = options.device or getdevice()
                                   ^^^^^^^^^^^
  File "c:\Users\...\projects\NanoVNA\nanovna-tools\nanovna_command.py", line 30, in getdevice
    raise OSError("device not found")
OSError: device not found

Correct, it is not there.
And now with an attached tinySA (but this doesn't make a big difference, the communication is identical to NanoVNA):

c:\Users\...\projects\NanoVNA\nanovna-tools>python nanovna_command.py help
commands: version reset freq dac saveconfig clearconfig data frequencies scan scanraw zero sweep test touchcal touchtest pause resume repeat status caloutput save recall trace trigger marker line usart usart_cfg capture refresh touch release vbat vbat_offset help info color if actual_freq attenuate level sweeptime leveloffset levelchange modulation rbw mode spur load ext_gain output deviceid selftest correction calc menu text remark threads

Let's capture a screen shot:

c:\Users\...\projects\NanoVNA\nanovna-tools>python nanovna_capture.py
Traceback (most recent call last):
  File "c:\Users\...\projects\NanoVNA\nanovna-tools\nanovna_capture.py", line 19, in <module>
    import numpy
ModuleNotFoundError: No module named 'numpy'

c:\Users\...\projects\NanoVNA\nanovna-tools>pip install numpy
Collecting numpy
  Downloading numpy-1.26.1-cp311-cp311-win_amd64.whl (15.8 MB)
     ---------------------------------------- 15.8/15.8 MB 14.2 MB/s eta 0:00:00
Installing collected packages: numpy
Successfully installed numpy-1.26.1

[notice] A new release of pip available: 22.3.1 -> 23.3
[notice] To update, run: python.exe -m pip install --upgrade pip

c:\Users\...\projects\NanoVNA\nanovna-tools>python nanovna_capture.py
Traceback (most recent call last):
  File "c:\Users\...\projects\NanoVNA\nanovna-tools\nanovna_capture.py", line 20, in <module>
    from PIL import Image
ModuleNotFoundError: No module named 'PIL'

c:\Users\...\projects\NanoVNA\nanovna-tools>pip install PIL
ERROR: Could not find a version that satisfies the requirement PIL (from versions: none)
ERROR: No matching distribution found for PIL

[notice] A new release of pip available: 22.3.1 -> 23.3
[notice] To update, run: python.exe -m pip install --upgrade pip

Ok, try Pillow, the friendly fork of PIL:

c:\Users\...\projects\NanoVNA\nanovna-tools>pip install Pillow
Collecting Pillow
  Downloading Pillow-10.1.0-cp311-cp311-win_amd64.whl (2.6 MB)
     ---------------------------------------- 2.6/2.6 MB 11.9 MB/s eta 0:00:00
Installing collected packages: Pillow
Successfully installed Pillow-10.1.0

[notice] A new release of pip available: 22.3.1 -> 23.3
[notice] To update, run: python.exe -m pip install --upgrade pip

And next try...

c:\Users\...\projects\NanoVNA\nanovna-tools>python nanovna_capture.py

c:\Users\...\projects\NanoVNA\nanovna-tools>dir *.png
...
18.10.2023  14:05             5.059 NanoVNA-H_20231018_140517.png

TaDa!

HTH
Martin

[Ho-Ro]

If you have to process your VNA measurements scikit-rf will save you a lot of time. For storage of your measurements I propose the touchstone format v 1.1 (*.s1p and *.s2p, ), it can be processed by simple as well as professional tools.

There's a good scikit-rf introduction available. It requires a little bit of learning, but TANSTAAFL :)

[rjordans]

To add to this, scikit-rf even has a module that directly accesses the nanovna https://scikit-rf.readthedocs.io/en/latest/examples/metrology/NanoVNA_V2_4port-splitter.html