Safety Feature: Protect Channels during y-Movement

[BioCam]

Hi everyone,

This is an anti-crash PLR Safety Feature for channel movements in the y-dimension.

Problem Statement

Currently STAR.move_channel_y(channel: int, y: float) simply requests the machine to move a channel with a specified index to a y position, regardless of whether another channel might be in the way.

PLR users are forced to humanly memorise where each channel is in the y-position if they wanted to avoid crashes.

As a result, crashes of one channel into another are very likely to occur.

PR Content

I have added a couple of lines of code to STAR.move_channel_y(channel: int, y: float) which calculate the neighbouring channels' y-positions and the safe y-space (i.e. 6 - 635 mm in y-dimension) and raises an error if the target y-value does not fall into the safe y-range.

Example 0: channel_2 is surrounded by channels (i.e. there is a 9mm distance to them) -> triggers...

await lh.backend.move_channel_y(
    y= 496.0,
    channel=2
)

AssertionError: channel_2 y-target must be >= 50.9 and <= 50.9, is 496.0 mm,
  current y-position = 50.9 mm,
  Can you move the neighboring channels to create space for channel_2?

Example 1: channel_0 is tasked to move outside the safe y-range -> triggers...

await lh.backend.move_channel_y(
    y= 640,
    channel=0
)

AssertionError: channel_0 y-target must be >= 68.9 and <= 635, is 640 mm,
  current y-position = 528.6 mm,
  Can you move the neighboring channels to create space for channel_0?

Example 2: channel_0 is tasked to move "through" other channels -> triggers...

await lh.backend.move_channel_y(
    y= 60,
    channel=0
)

AssertionError: channel_0 y-target must be >= 68.9 and <= 635, is 60 mm,
  current y-position = 528.6 mm,
  Can you move the neighboring channels to create space for channel_0?

Next steps

I have added an assertion error if the channel is asked to move to the y-position that it already is in... I am not sure whether this is needed (I'm leaning towards removing it) but wanted to ask you for your opinion on this?

[rickwierenga]

thanks!