ASL functions able to redirect to() for i2c transmission

[trentgill]

From https://llllllll.co/t/crow-help-general-connectivity-device-qs-ecosystem/25866/475

NB: the discussion is focused on allowed redefinition of the to() to forward the values over the i2c bus. this is likely related to #67 in that it's based on ASLs that do things other than control the CV outputs.

I like the idea of using asllib-style helpers for ii commands. There could be 2 backends: 1) breakpoint style for modules that have ‘slew time’ built in, 2) streaming mode for just setting values continuously with some update interval param.

If anyone has proposals for syntax that’d be a good start. Maybe something like:

 — make an ASL
erlfo = Asl.new()

erlfo.to = ii.er301.cv — redirect ‘to’
erlfo.throttle = 0.1 — update every 100ms

— works like a normal asl
erlfo.action = lfo()
erlfo()

Note how this could be done as:

1. a streaming service where the values are calculated on crow and streamed to the follower at a user determined rate.
2. a breakpoint approach where each to is implemented as a .slew and .volts pair
3. a combination of the above, using small linear-slewed segments based on actual output voltages

The 2nd option is easiest to start with as it's a direct replacement for to and only requires some method for tracking time (ie an ASL which doesn't calculate slopes, instead just decrements a timer). Sacrifices the ability to do non-linear curves (unless the destination device supports those too).

First option is only real option for devices that don't support 'slew' commands for the destination parameter. User must have control over interval as we want as low as possible for less 'steppiness' , but this is a tradeoff against bus stability (especially if controlling multiple simultaneous channels).

Last option is likely an unnecessary complication. It's limited in scope (only works on devices with slew commands), is worse in terms of time accuracy, and benefit is small compared to option 2.

[trentgill]

This can likely be written using the new norns clock module once it's ported to crow, and then turned into a small library that wraps the same contexts. it could then have ii versions of asl functions, and wouldn't require drastic changes to either ASL or ii handling.

[trentgill]

Closing as it should be implemented as a userlib once 'clocks' are included per #339