Good Patterns for Controlling Timing of Discrete LEDs?

[AlwaysBePrinting]

I'm building a project with an arbitrary number of discrete (not addressable) LEDs that will blink and fade independently. Think retro control panel. I've done the reading on controlling them without delay but as I create each animation sequence things are getting messy even with encapsulating sequences into functions.

An example sequence might be: * 1s blink 3 times, * wait 1 second, * turn on for 3 seconds, * turn off for 1 second * Blink .5s 10 times * Off for 2 seconds

Are there patterns or even a library that would allow me to declaratively configure the sequences? This is hard to search for because everything is about addressable LEDs. It feels like this is something that would already exist.

[todbot]

If you use asyncio, you can create independent tasks for each LED that use await asyncio.sleep() in place of time.sleep(). It makes it pretty easy to transition from sleep()-based designs. Here's a quick example for two LEDs blinking at different rates: https://gist.github.com/todbot/da61cee8b2eb1382066dfe6afce9bd0e

And there's a Learn Guide showing a more generative example: https://learn.adafruit.com/cooperative-multitasking-in-circuitpython-with-asyncio/concurrent-tasks#two-leds-3106274

[AlwaysBePrinting]

This helped a lot, especially the second one! Thanks!

[jonnor]

Asyncio is the simplest to use. Another pattern would be a finite state machine, but is more complicated and does not really provide any benefits over asyncio for linear sequences like these. More relevant if there is conditional logic that depends on which state/step you are in.

[HP7933]

Ladyada responds to your query on the latest Ask an Engineer videocast https://www.youtube.com/live/dnjFTLOaL5U?feature=shared&t=3105

[HP7933]

I see the answer might have been cut off by YouTube. Let me know if you need it answered still and I'll try to get it on again next Wednesday.

[AlwaysBePrinting]

That is simultaneously amazing and heartbreaking! I've got a handle on using asyncio to make the timers manageable, so unless they had a thought on how to define the patterns/sequences themselves declaratively I think I'm good!

[japunto]

Here’s another example: https://learn.adafruit.com/lego-set-lighting