Offset calibration on Windows

[Maddo534]

I use a Hantek 6022BL wit OpenHantek on Windows 10.

On both channels the signals are always offset by some mV, even when the Probes are connected to GND.

[Ho-Ro]

This is the typical behaviour without offset calibration. I see 500mV/div with x10 setting -> real range 50 mV/div where 1 digit equates about 4 mV. So the displayed offset of 320 / 520 mV is real 32 / 52 mV, which equates 8 / 13 digits (a not so unusual value, caused by the brain-dead HW design of the scope).

Please follow the hints for calibration.

[Maddo534]

Thank you very much for your answer!

I had to include/change specific paths to some files in the python code for it to work.
But except from that the calibration process worked fine and the problem got solved.

[Ho-Ro]

I had to include/change specific paths to some files in the python code for it to work.

Please provide your changes - this will help other Win users.

[Maddo534]

Here are the things I did to get the calibration working.

First of all a little disclaimer for any incorrect terminology or strange solutions.
This was the first time I ever had something to do with python and my knowledge about this consists purely from some googling such as trial and error.

First I downloaded the complete Hantek6022API folder here:
https://github.com/Ho-Ro/Hantek6022API

Also I needed to install libusb1 using pip.

For the calibration I used calibrate_6022.py in the examples folder of the API.

To this file I added the following at the top of the code:
import sys
sys.path.append('path\to\this\folder\Hantek6022API-master')

To the file LibUsbScope.py, located in a folder named PyHT6022 I had to add the same code, also right at the top.

When I tried to run everything now there still was an error that libusb-1.0.dll could not be found.
The dll is located where libusb is installed.
On Windows it should by default be here:
C:\Users\User\AppData\Local\Programs\Python\Python38-32\Lib\site-packages\libusb_platform_windows

The solution to this is definitely not a nice one but it worked.
I took the libusb-1.0.dll file from the above path and copied it to
C:\Users\User\AppData\Local\Programs\Python\Python38-32

After I did this I could run calibrate_6022.py from the windows command prompt without any errors.

[Ho-Ro]

Did you install Hantek6022API? Probably not, I see that this step is missing in the README.md, so I will give you a quick hint (please check if I'm correct, because I do not use Windows and do not have a Windows PC available for testing).
Own Python packages can be installed typically with python3 setup.py install, regardless of the OS. This copies the components into ...\site-packages\... and they become visible for the example programs.
Under Debian Linux, where I develop, this step is hidden in the Makefile under the target install:, which is also used when building an Debian installation package.
Sorry for the confusion!

[Maddo534]

Installing solved the issues I had earlier.
But the first time I ran calibrate_6022.py a new error occurred.
The firmware for the scope wasn't where the software searched for it.
After I shifted the firmware folder to the directory the software expected it to be everything worked again.

But I'm not certain if this is a general problem if you do this on Windows or if it roots in my lack of experience with python and thus an me-made error with the installation, some directory or whatever.

A definitive thing to say is, that when you install Hantek6022API less tweaks are necessary.

[Ho-Ro]

I opened a new issue #8 in the right repo, to concentrate all discussion about the python tools under Windows.