jerich (u/jerich) - Readit News

jerich commented on Ask HN: What are the best programmable holiday lights? · Posted by u/sh1mmer

A lot of people here are recommending WLED for the controller, but I would suggest you look at the Pixelblaze [1] instead. I've used both in a bunch of different projects and strongly prefer Pixelblaze over WLED.

Some reasons why: - It has a much more intuitive user interface - It's far easier to program new patterns. Programming is done in-browser with a language that's a subset of Javascript, with code changes being applied in realtime. - Due to the way its rendering engine works, the patterns it produces are generally far more 'organic' looking and smoother than most of the WLED ones. - It's possible to map LEDs in arbitrary 2D or 3D configurations (think lights strewn all over a Christmas tree), which WLED can't really do at all. - If you have multiple Pixelblazes you can get them to sync with each other over Wifi. - A really helpful community forum.

Downside: - The firmware isn't open source, though some of its tooling is, and the firmware is stable and gets fairly regular updates, so it's not a huge issue to me. YMMV.

For the LEDs, you probably want wired bullet-style strings of LEDs rather than the thin copper LED strips since they're generally more suited to outside use. By far the most common (and generally cheapest) type of LEDs are WS-2812B or similar. They're OK, though you might notice they don't have good definition at low brightness levels. APA-102 or equivalent are a bit more expensive, but have MUCH better dynamic range, so I'd suggest going for these if you can. There are other better (and more expensive) LEDs still, but it starts to become diminishing returns, plus they can be hard to come by or find suitable controllers for. If you're running lengths of more than a 150 or so LEDs then power starts to matter, and you'll either need to inject power regularly into the strips, and/or use LEDs designed to take 12V or 24V. These can come with caveats such as worse power consumption and/or fewer addressable LEDs per meter, so research what you're buying carefully.

[1] https://electromage.com/pixelblaze

jerich · a year ago

This gets such a huge thumbs up that I had to scroll up and reread it to make sure this wasn’t my own post from a revived thread from last year!

I’ve been using a pixelblaze with a long string of cheap 2812 LEDs on my Christmas tree for three years now with tons of compliments from neighbors.

I’m an embedded software guy, and every year I mean to dig in and try roll my own, or do something clever with an RP2040 board (also a shoutout for the Pimoroni Plasma), but the demands of life and “get the light show started” mean I keep using the Pixelblaze.

I even upgraded to their newer versions last year, and used some of the smaller ones to make some LED tutus for my girls that synced pattern with the tree (the tutus were synced with each other for a Christmas show, but it was trivial to then add the tree for fun afterwards).

The mapping is huge for the wow factor, and the pixelblaze makes it so much easier to get something fast and good enough.

There’s so many community-shared patterns to choose from, and it’s been easy to make small modifications to look better once mapped to a tree, though most work as-is.

My project I won’t get done this year is to try to make some calibration patterns and use ChatGPT to analyze some photos/videos to make a 3-D map, but I’ll realistically probably end up with the vaguely-triangular 2-D map again; I can get it done in about 30 minutes now.

The following is a couple years ago. I think last year I was up to 1100 LEDs and the mapping was a bit better, but I didn’t take good videos.

https://youtu.be/hu-RQx_NpAY?si=BMYbafbPAn2XAlU9

jerich commented on New iMac with M4 apple.com/newsroom/2024/1... · Posted by u/tosh

SurgeArrest · a year ago

Reading this on 2017 iMac 27" - is the first 5k iMac that couldn't be used as a monitor after the computer inside is irrelevant. I hope EU will push for some law that requires all AIO computers to work in monitor-only mode if internal hardware is no longer good enough or no longer supported by software updates. I love the 5k screen on this iMac but the CPU is too old for photo or video editing as software got so much slower over the years. I could have used this screen for many more years, but now it will hit landfill... Apple is only "green" in their presentations - in reality they care more about inifite sales only.

jerich · a year ago

Apple should hire a couple hackers to create “end-of-life” firmware for their obsolete devices; give them new life as super-specialized devices. Part green program, part customer delight, even some wacky art projects.

Maybe if an iMac doesn’t have a video input—have it boot as an AirPlay-only monitor.

I’ve got 2 old EOL appleTV boxes sitting in a drawer—again, one last firmware update to make them dedicated AirPlay receivers.

Take my 2011 MacBook Air and make it a dedicated Notes machine/word processor—all it does it run notes and sync with iCloud.

Obsolete iPad picture frame is an obvious one.

They can work on the “Reuse” side of the 3R’s of waste reduction (with reduce and recycle, right?)

PS, I’m available, 9 years embedded SW experience ;)

jerich commented on Earth rotation limits in-body image stabilization to 6.3 stops (2020) thecentercolumn.com/2020/... · Posted by u/pwnna

Euphorbium · 2 years ago

Eventually we will have to compensate for gallactic rotation.

jerich · 2 years ago

Anyone who’s read the short story “The Billiard Ball” by Asimov would have taken it into account.

jerich commented on Most to least common 4-digit PIN numbers from an analysis of 3.4M old.reddit.com/r/dataisbe... · Posted by u/lnyan

Clubber · 2 years ago

Someone tell The Los Angeles Angels.

jerich · 2 years ago

I think they’re over in line behind “The La Brea Tar Pits”

jerich commented on US Says Chinese Seizure of TSMC in Taiwan Would Be 'Absolutely Devastating' usnews.com/news/technolog... · Posted by u/belter

jerich · 2 years ago

So the US sells some bonds, then slips a couple trillion into a brown envelope to buy Baja California from Mexico, then “lease-to-own” it on very favorable terms (0 down, 0% APR, 150 years) to New Taiwan, or Formosa II. Uproot TSMC and an entire culture and move them over, then let China wave the flag over the mound of dirt left behind. Pencil them in to NAFTA and watch the chips flow over to the new iPhone plant outside Mexicali. Tijuana to Ensenada remains Mexico and is a buffer between them and the USA, and the night markets there are the envy of all food-eating people on the planet—-I can’t wait to try the albondigas soup dumplings.

jerich commented on Almost no one pays a 6% real-estate commission except Americans wsj.com/personal-finance/... · Posted by u/impish9208

jerich · 2 years ago

I think AirBNB has the infrastructure to upend the Realtor market. If they just add an “AirBNB listings” buyers can search and scroll through pictures. They’d have to show exact location, but otherwise pretty much the same as what’s there. Seller pays an upfront listing fee, gets referrals for staging and photos if they want to stand out.

Simply add a “30 minute viewing” rental for $25-$50 (AirBNB keeps $10-25), available to registered users (with already-verified ID). Maybe rent the homeowner a bundle of cams for viewings for extra security.

If a buyer is really interested, have an above-market-rate nightly rental—I’d love to spend a night in a house before paying a million+ dollars for it (without the cams, of course). Maybe half refunded with an offer made thru AirBNB Listings; full refund with an accepted offer (again, less AirBNB fees). Maybe partner with Redfin or Zillow to set prices, provide school and property info, and finish the deals. Do it all cheap enough to make it worth sellers forgoing an MLS listing; should be a flat fee, a tiny fraction of 6% in most cases.

A startup couldn’t do it, but AirBNB has the name recognition, and the pieces already there, right? I’m available for consulting, or send me a fruit basket if it all works out, a nice one, without a lot of melon.

jerich commented on WLED Project kno.wled.ge/... · Posted by u/tambourine_man

mmmmax · 3 years ago

This is an amazing project and if you like WLED you’ll also like Pixelblaze which is full-stack including a coding interface: https://electromage.com/pixelblaze

jerich · 3 years ago

I keep intending to reinvent my own controller with an RP2040, but life gets in the way, so for the second year in a row, I’m using a Pixelblaze to control the 950 LEDs on my Christmas tree. It’s a continuous string (well, 19 strands of 50 lights connected), put on the tree in a zigzag pattern and manually mapped to a vaguely triangular 2-D shape. The patterns are mostly as downloaded from the Pixelblaze repository.

I’d highly recommend Pixelblaze for getting a fairly complex setup working quickly.

https://youtu.be/hu-RQx_NpAY

jerich commented on Why doesn't the Fed just hike 200bp all at once? noahpinion.substack.com/p... · Posted by u/bryanwt

jerich · 3 years ago

Although I know financial markets are extremely complex and driven by human psychology, I can’t help thinking about thinking about it in terms of classical control systems.

Do you want a smooth input, or an abrupt step input? Psychologically, I’ve got to believe there would be a quicker response by consumers if rates shot up overnight vs “boiling the frog” with a gradual increases.

In simpler dynamic systems, you get a faster response with overshoot and ripple, maybe this would be similar? But would it be better? I wish the article author had been able to find more discussion by economists talking about the potential effects.

Could you pull out of a recession or pop a forming bubble in months instead of years? Maybe it could lead to a smoother Macro-macroeconomics. But maybe the overshoot is too much; maybe the system is just too chaotic to control effectively.

Financial markets dislike abrupt changes, but I think if the central bank was perfectly transparent about their goals and responses (“To maintain a annual growth rate of 1.9%, Fed decisions will be made based on a PID controller with the following parameters…”), some smart financial engineers should be able to account for the rapid changes in their own models. Maybe there’s even some profit potential anticipating the overshoot and ripple that could provide some dampening effects.

I’m sure I’ve completely Dunning-Kruger’d this and millions of lives would be ruined, but since I’m not the Fed Chairman, we’re all safe.

jerich commented on New MacBook Air with M2 apple.com/newsroom/2022/0... · Posted by u/todsacerdoti

theriddlr · 3 years ago

The base MacBook Air had its price dropped to $999 in 2013 and battery life improved to 12 hours. That's what got me onto the Apple bandwagon.

jerich · 3 years ago

After growing up on a Mac SE and going off to college with a Centris 650, I went through a string of windows PCs until the 2013 MacBook Air brought me back into the fold.

I still use the 2013 MBA almost daily—mostly as an external keyboard and screen for my iPhone notes, but it really slowed down with Mojave, so I’m trying to decide whether to pick up a cheap replacement M1 model now, or wait for sales on the M2. I think I can hold out a little, but won’t quite make the 10 year mark.

BTW, the c. 1993 Mac Centris was able to boot up last year (at 28 years old!), and thanks to an Ethernet adapter I dumpster-dived from work in the early 2000s, I was even able to get online with it without any extra configuration. Netscape Navigator doesn’t do too well with modern websites (and probably made for a baffling entry in some server logs), but I could at least load the Dole/Kemp ‘96 site.

jerich commented on H.264 is Magic (2016) sidbala.com/h-264-is-magi... · Posted by u/goranmoomin

tzs · 4 years ago

Two questions for the compression gurus here.

Suppose you have a bunch of raw video. You take extracts of it and put them together to make a movie, M1. You make an H.264 encoded copy of that. Let's call it C1.

You then make a new cut of your movie, M2, which is mostly the same footage as M1 except that you've shortened a few scenes and lengthened others. You make an H.264 encoded copy of that. Call this C1.

When making C1 and C2 your H.264 encoders have to decide which frames to turn into I-frames and which to turn into P-frames.

If they just do something simple like make every Nth frame an I-frame then after the first different between M1 and M2 it is unlikely that C1 and C2 will have many I-frames in common, and therefore also not have many P-frames in common.

If they look for scene changes and make new I-frames on scene changes, then we might expect that at least for the scenes that start identically in M1 and M2 they will get identical I-frames and P-frames up to their first edit if any.

Scenes that are edited in the front would still end up encoded totally different in C1 and C2.

Question: are there any encoders that when encoding M2 to produce C2 can be given M1 and C1 as references using them to adjust I-frame spacing so as make as many C2 I-frames as possible match C1 I-frames?

That would allow C2 to be stored efficiently as a binary diff from C1. This could be handy if C1 and C2 needed to be checked into a version control system, or you needed to distribute C2 over a low bandwidth or expensive link to someone who already had C1.

The second question concerns recompressing after decompression. I actually thought of this question in terms of audio so will ask in those terms, but I guess it applies to video too.

Suppose someone has an uncompressed source S. They compress it with a lossy compressor producing C and distribute C to you. You decompress C producing S'.

You then compress S' with a lossy compressor (the same type that the original producer used--e.g.., if C is an MP3 you use an MP3 compressor) producing C'. I don't know about video, but for audio (at least back in days when MP3 was starting to get big) C' would be lower quality than C.

Are there any compressors that can figure out that they are dealing with something that already has undergone the "throw out imperceptible parts to make it more compressible" step done and just skip to the next stage, so they produce a C' that is a lossless representation of S'?

jerich · 4 years ago

For the first question, I ended up using this trick for a video editing app on Android phones about 10 years ago in order to cut video together on low end, out of date (Android 2.3) phones. They couldn’t handle video compression in a reasonable time and we didn’t want to upload/download to process on a server.

The point of the app was to sync the cuts to music cues, so each clip had a defined length. I ended up doing it all through file manipulation. You can cut into a video file starting at any arbitrary I-frame then trim it to the desired length. I would cut the input videos down to size then concatenate the files, replacing the audio with the new soundtrack at the end.

It worked great, only took a few seconds to create the final edit. Of course you couldn’t overlay text or filter video, but I still think it was a valid solution.

With the requirement of starting each clip on an I-frame, there was some imprecision in where your cut would actually start—an arteur might have a problem with their masterpiece being butchered that way, but it would certainly work well for some special cases like efficient distribution or being able to show a diff that a video was unaltered outside of timing cuts.