Additional support for PicoScope 4444

[rascustoms]

Ported fix for USB power from ps5000a to ps4000a.
Enabled Bandwidth Filtering for PicoScope 4444

[pep8speaks]

Hello @rascustoms! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

There are currently no PEP 8 issues detected in this Pull Request. Cheers! 🍻

Comment last updated at 2019-10-02 14:11:42 UTC

[hmaarrfk]

Looks good. Can you please fix the flake8 and pep8 errors. Since we have no other tests, these kinda act as a minimum barrier of protection.

[hmaarrfk]

i guess there are some new flake8 errors that poped up recently. fixing them in #152

[rascustoms]

No problems on the pep, I'll have it done shortly. Would it be worth also addressing #58 in fixing the power settings? Could we add another default value to the class (not unlike addressing the bandwidth options) as to what behaviour the user wants?

[hmaarrfk]

I think maybe the correct fix seems to move:

        # This will check if the power supply is not connected
        # and change the power supply accordingly
        # Personally (me = Mark), I don't like this
        # since the user should address this immediately, and we
        # shouldn't let this go as a soft error
        # but I think this should do for now
        if m == 0x11A:
            self.changePowerSource(m)
        else:
            self.checkResult(m)

        self.model = self.getUnitInfo('VariantInfo')

To the high level wrapper.

We can then add a parameter: 'power_source' that would be None, DC, or USB where None would enable some magic to happen, while DC and USB would allow the user to specify exactly the source they desire.

[hmaarrfk]

again, I have a philosophy that I want this to work for you the contributor, and for now, this isn't a blocker for me. If it is a blocker for you, then we can work to address it.

[hmaarrfk]

I think the refactor should just happen elsewhere. It will also require careful consideration. If it does depend on the device class, we can add secondary conditions to the if statements