Extend APT Motor Controller to set / get home parameters #337
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| homing velocity to be changed. | ||
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| .. note:: When setting the quantity, pass `None` to values | ||
| that you want to leave unchanged (see example below). |
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I thought this would be neat for the setter. For my current application, I don't care about the velocity or which way around the limit switch works, I just want to leave that at default and only want to adjust the offset. This way, I can pass None for values I don't want to change and set parameters that I want.
| NotImplemented, | ||
| NotImplemented, | ||
| u.Quantity(42941.66, u.sec / u.deg), | ||
| u.Quantity(14.66, u.sec ** 2 / u.deg), |
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Weird thing here: Distances are incorporated as "encouder counts per degree", however, velocity and acceleration according to the Thorlabs manual table as scaling factors... It's also not counts per second, so leaving velocity units away.
instruments/thorlabs/thorlabsapt.py
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| req_units = (1 / self.scale_factors[1]).units | ||
| try: | ||
| velocity = int( | ||
| (velocity.to(req_units) * self.scale_factors[1]).magnitude |
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I would have liked to include this in a nicer fashion and simply divide by the scaling factor. However, somehow pint seems to not notice dimensionless units when doing math, e.g.:
>>> a = 1*u.m
>>> b = 1*u.cm
>>> print(a/b)
1.0 meter / centimeterIf you do the same with identical units, it comes out as dimensionless. Need to check more, might be a pint issue? The workaround here is functional
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Turns out, this can actually be done in pint and I should have just read the manual... Solution is:
c=a/b
c.ito_reduced_units()This makes it dimensionless.
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Yeah I was going to mention today that these libraries usually have a function that needs to be called to actually reduce the units to base SI
instruments/thorlabs/thorlabsapt.py
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| # replace values that are `None` | ||
| if None in values: | ||
| set_params = self.home_parameters | ||
| for it in range(len(values)): |
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😉
values = [x if x else y for x, y in zip(values, set_params)]
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then i also don't have to convert potential tuples to lists first
instruments/thorlabs/thorlabsapt.py
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| home_dir, lim_sw, velocity, offset = values | ||
| # check validity of unitful values | ||
| if not isinstance(velocity, u.Quantity): | ||
| velocity = int(velocity) |
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If its NOT an instance of u.Quantity, cast it to an int?
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I think I'm just getting tripped up by the comment
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the comment is indeed just wrong. pretty self-explanatory i guess.
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actually: moving it to int anyway when the package is created, where it makes more sense. so there's no reason to do it here - neither with the offset.
For APT Motor Controllers, homing parameters can be set. This was so far not included in
ik. Now it is, and tested (w/ pytests and with a "PRM1-Z8" stage).Small addition to the overall monster APT driver.