[HN Gopher] Over-engineering an RGB LED strip: let's make a cust...
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Over-engineering an RGB LED strip: let's make a custom programming
language
Author : misterdata
Score : 68 points
Date : 2022-07-17 17:28 UTC (5 hours ago)
(HTM) web link (pixelspark.nl)
(TXT) w3m dump (pixelspark.nl)
| flaviut wrote:
| This is very cool. And very generalizable, there are many
| situations where you want something like a scripting language for
| a MCU, and the VM implementation here is very straightforward.
| dtagames wrote:
| You had me at Lua. It's cool to think that runs on an RGB strip.
| I'd do it there but kudos on going all the way down!
| claxo wrote:
| Kudos to the author.
|
| The readme links to a protocol.md that lives in a private
| repository, any posibility it gets copied to the github repo?
| solarkraft wrote:
| This is nice. I once tried to get programmatic animations running
| on MicroPython, but it seemed to fail to load even the simplest
| color conversion class (I didn't have an ESP32 back then).
|
| I also tried streaming patterns (could've been really cool to
| hook it up to something like ColorCord), but my Wifi connection
| was definitely also too unreliable for that (hmmm, what about PoE
| LED strips?).
|
| There's some project based on Javascript (I think) with in-
| browser previews for the patterns, but it's proprietary and only
| sold as pre-flashed modules. I forgot the name, but I think it
| has been posted here.
|
| This bytecode-custom-language solution definitely looks over-
| engineered (wish I could use a language I already know to make an
| animation), but damn, it should be efficient. I think I'll play
| around with it bit.
| thanatos519 wrote:
| > There's some project based on Javascript (I think) with in-
| browser previews for the patterns, but it's proprietary and
| only sold as pre-flashed modules. I forgot the name, but I
| think it has been posted here.
|
| That would be the PixelBlaze from https://electromage.com/
|
| ... and it's super-duper-amazing for _actually finishing_ LED
| projects. While the code on the ESP32 is proprietary,
| everything else is very open and the community is awesome.
|
| If your name is Sisyphus or you just want to hack on LED
| electronics and maybe make some lights blink, anything else is
| fine.
| jedberg wrote:
| There already is a custom programming language for LED lights.
| It's called E1.31, and there are open source programs that exist
| to program in it (one of the most popular is called Xlights).
| It's what most people use to make their programable Christmas
| lights shows, and it also is the same protocol used in stage
| lighting.
| misterdata wrote:
| If I understand correctly that's 'Streaming ACN' e.g. more or
| less DMX512 over IP. In that case the image is generated on a
| beefy lighting desk/computer, not on the microcontroller inside
| the fixture (which is what this and e.g. the Lua project linked
| in another comment does)
|
| WLED (firmware for ESP8266) appears to support E1.31 [1] as
| well as Art-Net and the WLED custom protocol referenced in the
| article.
|
| [1] https://github.com/Aircoookie/WLED/wiki/E1.31-DMX
| garaetjjte wrote:
| I'm surprised you didn't use floating point math, it seems
| cumbersome to make animations that way. My attempt at
| programmable LED strips used Lua (like that:
| https://gist.githubusercontent.com/Milek7/760a683f3480a4ff95...),
| though they were driven directly from Linux SBC.
| https://milek7.pl/.stuff/26gru.webm
| misterdata wrote:
| Floating point is just not very fast on ESP8266 (I believe it
| could even be softfloat, so emulated in software?).
|
| Nevertheless it shouldn't be that difficult to change the
| interpreter to use floats instead of ints as base type (mixing
| the two would be more involved I think).
| manofmanysmiles wrote:
| This might interest you as well:
|
| https://www.bhencke.com/pixelblaze
| redfast00 wrote:
| Related: a multi-program programmable LED strip (in Lua, allows
| the led strip to be split up into multiple segments)
| https://zeus.gent/blog/21-22/ledstrip_sandbox/ with the code on
| https://github.com/ZeusWPI/ledstrip_sandbox
| misterdata wrote:
| This looks cool! Lua obviously is a much more mature language.
| I'd expect it to use a fairly complex interpreter (LuaJIT is
| not available for esp8266 I assume..) so this is likely a bit
| less efficient (even though the Lua interpreter is probably
| well-optimized, it is simply more complex) but obviously much
| more functional than my toy language.
| Tempest1981 wrote:
| How did you implement "sleep"? For timing the effects?
|
| I see a 'get_precise_time' command. I guess you could poll that,
| if you aren't worried about power use. (LEDs using far more power
| than your CPU.)
| misterdata wrote:
| The interpreter will throttle the program to a certain frame
| rate - it will suspend the program on each 'yield' instruction
| and resume the program when a new frame is needed. It can also
| ignore the yields to get as high a frame rate as possible.
| Programs should not poll but use get_precise_time to draw what
| is necessary for that time stamp.
|
| (And yes, the LEDs use way more power than the CPU here)
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(page generated 2022-07-17 23:00 UTC)