Driving hub75 LED panels. (including free test software)

It turns out that the video wall panel used in the TV series Project MC2 merchandise is actually a standard 75hub LED video wall module.
These modules are "dumb" in that they require a continuous stream of data being updated and scanned at high speed to create an image. This is quite an intense processor load, so these modules are usually used with dedicated drive cards that can receive image data and then output it at high speed to a grid of these panels.
Having identified the chips on the back of the PCB and sussed out how they might be driving the LEDs I attached a PIC microcontroller and wrote some software to drive the panels.
Initially I wrote a simple routine to display a single line of a single colour. The usual "Hello world" test to see if I had deduced the drive system correctly.
I then wrote a bit of software that can test the panels completely using a single microcontroller (PIC16F627A) with no other additional components other than a standard 100nF decoupling capacitor across the power pins. The same 5V supply used to power the panel can be used to power the test circuitry.
It starts by testing all the LEDs by displaying a full-panel colour sequence of red, green, yellow, blue, magenta, cyan, white and then a set of colour bars. Then it tests the output enable pin of the module by toggling it while displaying two lines of white LEDs which will flash if output enable is working. The microcontroller then tests the row drive MOSFETs by stepping through each line in turn on the top and bottom halves of the display simultaneously.
You can download the assembly and hex code files for this software with the following link, noting that the hex code can be directly loaded into a blank chip with a PICkit 2 or 3 programmer.
www.bigclive.com/freebies.htm
That same link can also be used to find the other test software that generates a continuously scrolling pseudo random pattern of coloured pixels that are dynamically generated in real time by software as each line is loaded during the screen refresh cycle.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
www.bigclive.com/coffee.htm
This also keeps the channel independent of KZbin's advertising algorithms allowing it to be a bit more dangerous and naughty.

[@GarryElliottComedy]

Only discovered your channel in the last month or so and I’m lovin’ it! I’ve even ordered some kits from eBay to practice on. Keep up the good work 👌🏻 ⚡️

[@drteeth7054]

I love watching such amazing stuff that is so well explained, especially if I don't understand a word as in this case.

[@Neffers_UK]

Clive, you are a bloody genius. I have a young nephew with autism, and he responds well with sensory toys when stressed out... the bonus part would be ideal for him to play with. Guess on pay day I'm going to look for a couple of these panels for him to inevitably destroy. Thank you for the idea. I deffo need to buy you another coffee or two. It's long over due that I repay you for your content that I enjoy so much.

[@angrycreeper100]

hmm you could look at getting a ws2812 panel and an arduino. with a program called glediator you can send patterns and animations to it. hackaday.io/project/5714-glediator-from-sdcard-arduino here is some info about a guy that made one

[@Crushonius]

@@angrycreeper100 exactly and if you fear that he might destroy it embed the led panel in epoxy and it will be practically indestructible

[@markfergerson2145]

I was just thinking that bringing the contacts out to a set of brass furniture nails on a piece of wood would make it a sort of video theremin. I'm an adult Aspie and *I* want to play with one of these!

[@Zenodilodon]

Good job! That's a great set up! I don't know much about making my own programs but that is such a handy thing to make in the future for testing and repairing video wall panels. Often i have to run a whole unit and mark off LEDS like that, a small tester plug is a superb idea. I might have to look into making one of these within the year.

[@wallyman292]

system programmer on IBM mainframes for 30 years. Assembler was my bread and butter. Gotta like the bit level control it provided.

[@mikeselectricstuff]

The output enable isn't strictly speaking used to blank the whole panel, it's used for the intensity modulation - you load the data for one bit of the intensity, and pull the enable line low for a precise time. proportional to 2^bit

[@bigclivedotcom]

Is that in the style of the pulse frequency modulation that Pulsar used to bypass the CK patents? The PWM style cycle was implemented as a series of smaller binary pulses with a length of 1,2,4,8 etc.

[@UpLateGeek]

Wow, these things have gotten a lot cheaper than the last time I was looking at these a couple of years ago! Definitely going to have to pick a few up for some projects I'd shelved due to cost!

[@DC_actual]

I bought three of these after the last video, and just last night I actually hooked one up to a Raspberry pi. Super cool.

[@RavenLuni]

So many of my favourite things mentioned here - PICs, aseembly, ZX Spectrum :)

[@AntonioClaudioMichael]

Very simple light panel and very nice setup

[@lumpyfishgravy]

I can tell you had a lot of fun! The 16F627 takes me back. I avoid PIC16s these days if I can due to that 8 level stack limitation. And since Cortex M0s have come about I avoid PICs altogether. The silicon is fine, but the tools suck bad.

[@551moley]

On a good day I understand 60% of what Clive says maybe even 80%......today's not a good day 5%...off to look at diggers.

[@simontay4851]

Same here, i don't understand most of what he's saying and i don't have one of these LED panels and don't intend to buy one. £20 is a lot of money to waste on something to just mess about with. Plus i wouldn't know where to start with programming a microcontroller in assembly.

[@Lumibear.]

Yeh, I know what you mean, usually I can just about follow, but to me this one sounds like “This ws854 address gaterade, pulsed at an xk24 hz bilateral pluke, gives the multiplex binary mosh-phets a 4 fold increment on the 3.9 xp manifold tandem, thus reseeding the 512 bit multicore processing gantry into a linear feedback recycling gooch” oh, absolutely, Clive, (nods sagely)

[@danyf3116]

Thank goodness. For a moment, I thought I had lost all my knowledge of electronics!!! LOL

[@edwardhugus2772]

I think that's Big Clive doing his mandatory monthly broadcast to his homeworld. It isn't really meant for earthlings, but he is obligated to "Phone Home" on occasion.

[@bertblankenstein3738]

I got one of these panels, also got a hat for the raspberry pi to drive it. I have a demo running, but I like the idea of a ws2812b much better than hub75. Driving the hub75 panel is not nearly as simple as a ws2812. Thank you Clive for adding to my hub75 knowledge.

[@dom1310df]

Well, I guess I'm going to have to go buy a pink purse to rip the video wall module out of it

[@northshorepx]

You mean another one!!!

[@LiezerZero]

I've got 9 of them.

[@LordSandwichII]

@@LiezerZero So you only need another 4071 to make a 1080p display.

[@jmibk]

You can get. the modules for cheap at ali express. make shure they have that hub75 connector on it (most of them have)

[@ianide2480]

Dominic - you ever imagine that you would use that particular sequence of words in that order? heh

[@LiezerZero]

I've been waiting for this video... Well done. Mine shows BTC to USD price while turning green or red depending on sell or buy. With a Pi Zero, it takes up 50% of the cpu to drive the matrix.

[@6yjjk]

7:05 Nyan-cat meets jet engine.

[@samiraperi467]

Thanks, now I have nyancat in my head. :D

[@matsv201]

We made something simular in the 90-tys with 800 leds (5mm once) for a scrolling text sign... Also used a PIC for it. But what we did in steed was driving the leeds with voltage then have voltage rails and transistors for every row to flip it on and of. The put a triable DC/DC stepdown to each rail the trim it so each transistor draw the corect amount of current. This was a very effective way of doing it

[@nutsnproud6932]

Thanks Clive. Its very interesting.

[@Furiends]

It took me a bit to understand what Clive meant by "multiplexed in real time" so I'll explain it for others who think like me. Because the data is multiplexed the same data needs to be reflashed many times in order to maintain persistence of vision in the animation. You either need to store the data to be multiplexed or regenerate it each cycle. Clive actually does a little bit of both since there's two multiplexed sets of 8 rows.

[@SomeMorganSomewhere]

Yeah, test patterns are good ;) When I used to work with LED signs the quality out of the manufacturer tanked (for reasons). It got to the point (after we got them to fix the melting power connectors) where we'd have to leave them displaying solid bars of colours for 4 days straight before we'd actually dispatch them to clients. Before I left about 50% of the boards were going back to the manufacturer due to dead pixels, dead blocks or baked power supplies...

[@ZILtoid1991]

>Linear Feedback Shift Register >Random "Any one who considers arithmetical methods of producing random digits is, of course, in a state of sin." - John Von Neumann

[@cambridgemart2075]

Assembly language and machine code aren't the same thing! Assembly language has to be converted to machine code by the assembler. Programming in machine code is a very painful pastime!

[@KeepEvery1Guessing]

Painful, yes. But back when assemblers cost money, it was good to have the option.

[@d2factotum]

I used to hand-assemble code on my ZX Spectrum back in the day. Most complex thing I ever did was something that would generate a Mandelbrot set--even with it generating the set at half resolution (so I could use bit patterns in lieu of colours) it took 2 hours to complete the whole thing!

[@nickbird7742]

@@d2factotum wasn't you the posh one, I only got the ZX 81.🤣

[@frankowalker4662]

I still program in Machine Code on my Spectrum. I find it quite relaxing, having to chase down all those 16bit addresses! Ha Ha!

[@adaai2384]

They're the same thing in the sense that pre-processed assembly is just mnemonic machine code.

[@LordSandwichII]

To make a 1080p HD display, you would need 4080 of these! :)

[@vgamesx1]

Assuming these panels are about the same size as the ones on adafruit which are 192mm x 96mm (7.6" x 3.8") big, meaning to make a 1080p wall out of them it would measure in at (I made a massive error) -783360mm x 391680mm (31008" x 15504") or 783.36m x 391.68m (2584 ft x 1292 ft)- 11.5m and assuming a cost of $15 per panel would be $61,200 with 4080 of them. -To put that into perspective, according to --stack.com-- a football field is around 109.72m x 48.77m (360ft x 160ft) meaning you could fit about 7 fields inside of your display.-

[@noinformationhere4258]

@@vgamesx1 It seems like you got something wrong there - a 1080p panel of these would be around 6.5 m x 11.5 m assuming a panel size of 96 mm x 192 mm.

[@AttilaAsztalos]

@vgamesx1 Arithmetic would like to have a word with you. These are 32 pixel wide, and a HD 1920x1080 screen would need 1920 / 32 = 60 of these in width. At 192mm each, that's 11.5m; rather large, but nothing comparable to any football fields. Kinda makes sense, seeing as how that's pretty much what Jumbotrons are made of, and as large as those are, they're still far smaller than the stadium itself...

[@vgamesx1]

@@noinformationhere4258 @Attila Asztalos Oh right, oops... I just multiplied both numbers by 4080 (didn't even double check that was correct either) and forgot it doesn't work that way... Lol

[@brandonmartin-moore5302]

Isn't that basically how they make those big LED walls used in, for example, game shows?

[@poopandfartjokes]

You are an uploading beast! Let’s take something to bits.

[@Blowcrafter]

have you worked with the 32bit pics before? The dma module + pwm module can be used together to make a moderately fast and 8 bit PWMed one of these. With the bonus being, that you have all the processor time effectively free (the only thing it would be doing is shuffling bits into the right location). i actually built a "game" machine that way (obviously only for things like pong/tetris etc. because of the resolution)

[@nickbird7742]

From what you have said, I hope that you also may a video about these card's for people like me that would like to learn more

[@Blowcrafter]

@@nickbird7742 interesting idea. i can try to but i am currently learning for exams so that would be a while until i do🤔

[@nickbird7742]

@@Blowcrafter not to put you any pressure on you i shall subscribe to your channel with the hope you can do a video, however I wish you all the best in your exams.

[@Blowcrafter]

@@vek7933 sorry but i already beat you to it ;) + tetris :D

[@braeburnhilliard8340]

Wow, that's cool. I can almost do the magic eye with that displaying! Did anyone else see that Clive's hand look like they were in a cartoon while they were in front of that board? A picture of the

[@vintagecameras9623]

Great channel you have

[@revoxsvko]

Yay, uploaded on my bday!

[@AntonioClaudioMichael]

Very nice assembly code

[@adrianrabbage4996]

Big Clive's subliminal messages and mind control, 'you will be assimilated'. :D

[@na_dann_mal_los]

Yap, he is Borg ;)

[@airgunnut9489]

@@na_dann_mal_los no hes Scottish :p

[@Darieee]

Beautiful commenting of the code !

[@bigclivedotcom]

I've always commented heavily. Makes it easier to revisit the code for modifications.

[@mikehunt9815]

nice follow up of your pink purse video, I've been involved with build steel work for exhibitions, that use the full size panels, heavy little beasts lol

[@NotIT]

You can cascade these. I picked up 6 when the purses were $9.50 (have since gone back up). I added sockets to the empty pads and tried it and it works perfectly fine. Also the purse's controller has a 'hidden' test pattern routine built in if you hold button while turning it on (2-3sec. hold).

[@jagardina]

This was awesome.

[@johnbouttell5827]

Strangely therapeutic.

[@edwardhugus2772]

I tried Google translate, but it doesn't have that particular language you are speaking. You DID say " It's really quite simple" and I DO trust what you have said in the tons of your videos I have had the pleasure to watch. The next time you "Phone Home" to Krypton, could you please leave a translation for us mere mortal earthlings? Oh well, It still gets the usual thumbs up from me, I just wish I wasn't left feeling like a third grader at an MIT lecture.

[@tonysever9217]

clive ,awesome content also took things apart to see how they worked. But the electonics side . I understand circuit diagrams. I dont undstand the flow , your videos help when it comes to board diagrams and chips i am learning, Thanks man.

[@tonysever9217]

took things apart at a young age, to see how they worked

[@gregw1076]

Thanks for the initial video about this, I immediately checked and was able to get 3 of the purses for $8USD each. This video also inspires me to continue playing with it, semi-waiting for 16pin ribbon cables I ordered then plan to use a RPi Zero to run it. Don't have anything to work with PICs, so can't try out this software very easily. But yeah I might be able to test how to work them with the connection between two of the panels if you were interested I'm also very interested in knowing if the original chips could be used, and use something to load images via the audio cable it has (without using the official since my phone doesn't support it)

[@bigclivedotcom]

The finger trick mentioned at the end will provide instant gratification before you start dabbling with software.

[@astraymark244]

Bonus content, somewhat more therapeutic than popping bubble wrap bubbles 😁

[@soundguydon]

LOL - @bigclivedotcom : The day I watched your original 'pink purse' video, I bought two of those purses and ripped the displays out. I use my Raspberry Pi with the Adafruit RGB Matrix/RTC shield/hat/whatever (for ease of use) and I'm very happy with those purchases, considering the same bare panels are almost three times what I paid ;-)

[@willybee3056]

Another bright idea, with illumination. ..😆 Tnx

[@AlanLifeson]

The Teensy boards work well with these RGB matrix's. I use a Teensy 3.6 to display on 2 panels 32x64 pixels and it displays a series of GIF images. I also have a ESP 32 running with a 32x64 pixel panel as a clock with merging numbers with date and weather updated from the internet. These panels are cheaper on Aliexpress than the pink purses and you get a better resolution too.

[@crazygeorgelincoln]

Glad I hung around, I do have some unoccupied arduinos , but a sweaty finger does great also. Guess some results could be made by attaching an antenna.

[@hignaki]

Hah, after seeing your first video I picked up two of them for $4 a pop from Amazon, and then saw the price spike the following days. I've got them wired up to an rpi, and they're confirmed working, just have difficulty figuring out software to drive them. All I want is a clock with maybe my calendar events along the bottom, but sheesh I am not a programmer lol

[@aria8928]

I'd love a video on making a panel of this. Either scratch built or from some sort of kit.

[@Nono-hk3is]

I've been running them off a raspberry pi 3B+. I feed it 5 volts power but have been successful putting 3.3 volts onto the data pins, as that is what rpi gpio pins run at.

[@Blowcrafter]

strange, mine kinda worked, but at high speed the impedance of the cable resulted in enough drop to prevent it from working (lots of ghosting on adjacent pixels) and i had to put in a level shifter.

[@hignaki]

What software are you using to display things? I've got hzeller's test code up and running, but kind of want it to run a calendar app, but can't get anything to work.

[@johnfrancisdoe1563]

No no 3.3V logic is compatible with 5V TTL inputs, because 5V TTL accepts anything over 2.4V as 1, with real 5V TTL outputting 2.8V to 5V for a 1 (0.4V margin). 3.3V TTL jusr outputs 2.8V to 3.3V for 1. Beware however that most 3.3V pins don't like being fed 5V, so it's essentially one way. There is an ingenious way to do the level shift with a single MOSFET instead of a full logic gate.

[@makers_lab]

Definitely simpler than expected. Thought they'd use drivers similar to the TLC5940, which handles the PWM, dot correction for fine tuning of LED to LED matching, constant current drive etc.

[@mattbatt0]

Looks like a great way to make a clock.

[@bigclivedotcom]

It would make an interesting clock project.

[@chrisw1462]

Parallax makes the Propeller line of multi-core micros - cheap and made for process crunching tasks like this one. Fun to get everything coordinated though.

[@igmusicandflying]

Best part of this video is if you've trained your eyes to "free fuse" like you do to see 3D random dot stereograms for example you can do this watching this video and enjoy an even more spectacular hallucinatory experience.

[@AstAMoore]

As a ZX Spectrum programmer, I really dig this.

[@bigclivedotcom]

It's pretty much the same colour pallette give or take the second intensity level.

[@SimonSideburns]

Wouldn't it be great to display a ZX Spectrum screen on a 256x192 LED array made up of these panels, except it sounds like that would take some serious processing power and quite a high voltage not to mention the cost of purchasing the 72 panels required (6x12 unless my maths is failing me).

[@AstAMoore]

Absolutely. The Spectrum had a slightly unusual arrangement, though, with the lowest bit being blue, followed by red, followed by green (BRG, rather than RGB). So, numerically ascending values from 0 to 7 would translate into black, blue, red, magenta, green, cyan, yellow, and white, respectively. The brightness bit was simply ANDed with the color signals inside the ULA via a diode and a resistor, so a bright black would be the same as the non-bright black.

[@AstAMoore]

Yup. Was one of the first things that came to mind as I watch the video. We’d need a dedicated panel driver that would mimic the Spectrum’s ULA-i.e. continuously read data from the bottom 6912 bytes of RAM and then shift it down the panels. I’d love to see it!

[@triplexdread]

Awww pretty lights :D

[@SurajGrewal]

Holy cow! Assembly! Just the thought of it, gives me headache

I have being playing with a couple of LED panels like yours, very funny but very frustrating, as there a lot of different "standars" to drive them. You'll find lots of different multiplexing patterns, from yours, where you drive two straight 32 pixel lines at the time to others where you drive two virtual 64 pixel lines at the time, so you actually light 4 rows and, to make everything even more complicated, they may not be straight lines but "zigzagging" instead, this technique is supposed to make them less flickery to the eyes. I have even found one that uses a funny addressing method to save address decoder IC, where each of the address lines enable pair of 64 pixel lines (four 32 pixel lines). You could drive all lines at the same time using that panel, limited to display the same pattern on all the lines. To drive my panels, I have used an ESP32, making use of its DMA to do the hard work of "pushing" the data to the display and leaving a lot of CPU time free for other stuff.

[@simontay4851]

The problem with standards is that there are so many of them.

[@laustinspeiss]

I did something a few years ago for a large matrix LED dance floor, as a complete system, and the individual panels in each cell for diagnosis & repair.

[@girlsdrinkfeck]

when u said fruit machines the nostalgia hit me hard as a kid on holidays in wales with them translucent colourful rectangular buttons

[@bigclivedotcom]

You can get the illuminated fruit machine style buttons cheaply on eBay these days.

[@y0utubeu5ername]

Just for moment there I thought I was watching a mikeselectricalstuff video LOL. Very interesting.

[@budude2]

Look up the OctoScroller - a cape for the BeagleBoneBlack SBC - runs 64 of these panels (8x8) - these panels are the "new thing" for the Christmas lighting folks to run P5 or P10 panels.

[@avejst]

Thanks for sharing :-)

[@DavinDesborough]

It is interesting that your panel has the big EU printed on it. The purse I received here in the US has the exact same panel, minus the EU. It seems odd they would go through the trouble to use differently printed boards. I am assuming they were all made in the same factory.

[@bigclivedotcom]

Maybe a lead free version? Not sure.

[@plasmaburndeath]

Did you receive the tenth of a penny discount since they saved on power and possible ink with the U.S. version? 😋

[@DavinDesborough]

@@plasmaburndeath Nope, but I was able to get three of the purses off Amazon for less than $24. I'll consider that discount enough. 😉

[@plasmaburndeath]

@@DavinDesborough I guess you had luck with your "pursut... Lol I will hide now.

[@oldaccount537]

@@DavinDesborough could you link it?

[@pierreuntel1970]

Clive writing ASM? nice!

[@Neffers_UK]

Yeah, he's a really intelligent and creative person isn't he?! I wish I had his knowledge and skills. He's got some really cool projects on his website, PIC based RGB controllers etc. that he's developed for example. His projects have been ripped off by companies, and he's also the guy behind the "Joule Thief" that has also gone without credit, if you didn't already know. Have a great day :)

[@herrpez]

You can get his knowledge and skills. What you *really* need is the motivation. For me that's a big hurdle.

[@frabert]

@@Neffers_UK The way I understand it, Clive is the one who came up with the "Joule thief" name, but the actual circuit is older I believe

[@martinrocket1436]

SandPox, I am also a bit shocked that he didn't directly write the binary code but had the help of assembly.

[@HelloKittyFanMan.]

And what does "ASM" supposedly stand for, according to you?

[@stargazer7644]

Machine code is what an assembler assembles your assembly language into. It is the output of the assembler.

[@ezedjay]

Wow - your skills just keep appearing. Thank you for the .asm files and for those that don't get how impressive this is - Clive's got skillZ. With a "Z"! Did you learn on zx80/zx81s back in the 80's or did you learn even earlier? I've got two kids - the spatter you're referring to - it's mostly food, sneezes and food sneezes. Nice.

[@bigclivedotcom]

My first program was written on punched cards and I learned BASIC on a Cromemco Z2D. The ZX81 came later.

[@reggiep75]

This needs to be made into a Big Clive message scroller to be attached to safety gear of all kinds!

[@realnutteruk1]

I bought a nasty pink plastic handbag, and ripped the panel out.... Hooked it up to an Arduino Uno, with AdaFruit's software, and within an hour was displaying what I wanted.... Their "plasma" sample sketch produces wonderful patterns, although I prefer it slowed down a bit.... A Nano will do the job just as well...

[@argonman1]

Hi Matt, would you mind sharing your Arduino code? I would like to do the same. Cheers!

[@realnutteruk1]

My code is just modified from the adafruit sample code... This page tells you all you need to know: learn.adafruit.com/32x16-32x32-rgb-led-matrix/library

[@kevinjbakertribe]

Would be interesting to interface some of these to e.g. an Arduino FPGA board - that could do all the muxing & brightness control, providing a simple "fire and forget" memory mapped interface for the CPU.

[@stotty5822]

I bought one of the Pink handbags last week from the Argos outlet on Ebay,they are selling them at £8.00 including postage :-)

[@jangoofy]

02:29 "so what we have in the bag here" - Clive was waiting to say that :)

[@tonysfun]

Thank you very much! You are very talented guy! I wish I had your abilities! I'll try to recreate your results. Thanks for the details you are talking about. What Infrared Camera did you use to find the RED drivers/heat?

[@simontay4851]

Flir E4 firmware hacked to E8.

[@tonysfun]

Thanks for a quick reply! I was gonna get me a IR camera but based on review of Andreas Spiess, the less expensive models (what I can spend now on this) is basically useless! Your FLIR is a very nice IR but my budget is much less, so I must hold my purchase. But, is there something less expensive that works well, based on your experience and isn't gonna cost 1+k? Sunday, my friends and I are gonna try your samples for the RGB-LED-MATRIX. Let's hope we can make it to work!

[@twocvbloke]

Pretty neat stuff, would be fun to see it playing a really low resolution video though, or maybe a low-res oscilloscope, or something else that is way beyond my abilities with such things... :D

[@LarryAllenTonar]

Couple nits: (1) Machine code is represented in e.g. hex, octal, or binary -- what you can enter into a front panel of 1x8/16/32/36 bits with a memory-advance button, or on a boot punched card or tape or non-volatile boot memory back in the day. Assembly starts as a mnemonic representation of the above, and with macros, be even more terse and only requires two-pass assembly to get the jump addresses right. But isn't as abstract as, say coding in C. (2) In the second program, you were displaying pseudo-random data, not random data. Random data is something you might extract from a chaotic physical process, such as properly biased, amplified noise, and has no seed, except as an extraction parameter from a one-time pad of recorded random noise data. It would also be interesting to know how much light is output, and how well the panel would show up on, say, outdoor sunlit conditions, since it is already limited to 1/8th of the maximum possible continuous light output of whatever LED technology is used. Otherwise, thank you very much for an informative video.

[@ledmk2]

Nice

[@HelloKittyFanMan.]

Haha, how funny, your demonstration about replacing a chip with a finger!

[@kasanekona7178]

If you're interested in seeing how much performance and effects can be squeezed out of relatively simple hardware you should most definitely check out the retro computer (eg. Commodore 64) demoscene, if you haven't already.

[@bigclivedotcom]

I used to love the demos that were always playing in the software pirates lairs in the 80's.

[@wimwiddershins]

Regards bonus end bit. You could make a video theremin with something like this and challenge people's perceptions with 21st century jazz video art. Beret compulsory.

[@Gazereths1234]

Jazz, niiiice!

[@amicklich6729]

Where did your fascination with lighting, LED's or otherwise start? You seem the master in this realm. Just a curious question as I find it interesting (conversationally) why people got into electronics in the first place. Sometimes one thing comes before another. Best.

[@bigclivedotcom]

I've always liked lights from a young age. My first electrical toy was a torch bulb and a battery to make it light.

[@squalazzo]

Hey Big Clive, take a look at Brian Lough work, he did a very good lib for esp8266 for these kind of displays...

[@squalazzo]

one of his videos, but look at his channel for more: kzbin.info/www/bejne/j6e4kI2ce5ypqZY

[@chaos.corner]

Nice. Could make in internet controllable display.

[@johnfrancisdoe1563]

squalazzo That's quite a powerful chip.

[@AJB2K3]

I'm not sure if the LED count on that panel is increasing or I'm drunk!

[@etheroar6312]

At about 7:"15 on a 42" monitor, it reminded me of the late 1960s.

[@microcolonel]

I should send you a HiFive1 (I have a few spares). These things are crazy fast (320MHz [and some you can overclock higher]) and largely Arduino compatible (including physically), ideally suited for the upgrade version of your little PIC program. There are about 400k writes per field (512 * 3 * 256) if you want to run 8 bit per channel color (which may be overkill honestly). The HiFive1 has 16MiB of onboard flash memory, 16kiB of L1 Cache, and 16kiB of SRAM, so you could double-buffer the image and potentially display something pretty interesting. If you're just scanning out, you could do ~140-200fps no problem. You could probably even decode video on the thing if you tried. ;- )

[@Psi105]

You can drive them at 888 /24bit colour if you have enough RAM and a 32bit MCU with GPIO DMA. You DMA copy a large block of ram to a GPIO port wired to all the LED matrix inputs. Clock, RGB, address, all of it. Basically you're encoding data, address and clock into a large memory block you can step through using DMA. Then you can update RAM slowly as needed to set pixel colors while simultaneously having DMA update the entire display at a flicker free speed. One way you can do colour mixing is to DMA update the entire display 8 times in a row with each time having double the "on time" of the last. This matches up nicely to the bits in 1 byte (red for example). So red LSB is "on" for a tiny amount of time and red MSB is on for quite a long time. The ram usage is pretty crazy though, you need like u32 * pixel line length * number of lines * 8 updates for PWM mixing * 3 colors. and then you probably want to double buffer it so double that again

[@bigclivedotcom]

This is pretty much how the earliest home computers worked. With the ZX81 when you encroached on the video RAM with your program, half the screen suddenly disappeared to make way for it. And with the early computers the screens would glitch as you wrote data into the active video space.

[@plasmaburndeath]

Subliminal message received, and understood; execute code no nul output. Execution complete.

[@seannot-telling9806]

Clive do the red drivers get hot enough to cause worry about there longevity? If it's is going to be an issue would some small heatsinks be able to help? I was thinking the smaller ones with the thermal sticky tape to hold them in place. Ebay is going to love you with all the pink hand bag sales.

[@AntonioClaudioMichael]

Down to a volt is impressive

[@sniffy6999999]

Bigclive..........your'e REALLY smart. I'm green with envy.

[@lostjohnny9000]

Could you inject noise directly from electret mics? Simple sound to light units?

[@offontv]

nice feedback .. oohhh

[@agvulpine]

Curious what sort of refresh speed benchmarks you get, say for blanking full images, or scrolling reused data, or only partial drawing.

[@bigclivedotcom]

It can apparently handle very high speed data input. But it requires matching processor or FPGA power.

[@DC_actual]

I was just looking at the board that I pulled from one of the toy bags, and noticed it has an I2C header on it. I wonder if it would be possible to communicate with it directly.

[@ShumaiAxeman]

Video wall: my arch nemesis lol. At least the Roe Black Pearls are easy to assemble.

[@budandbean1]

Dude, you stole the kids stuff? Props to you!

[@mccc4559]

KZbin University does it again!!!

[@eidodk]

@bigclivedotcom Why not build a digital clock module for it for your wall ? Seems to me you could make it look really beautiful with a module like that.

[@gavinsmalley1513]

Well suited to an ESP32 as you can use one core to do the multiplexing and the other to do what ever processing is necessary to generate the image. Brian Lough has a video trying exactly that with one of these displays.

[@TheBodgybrothers]

You should used the ULP for the video driving, then you get 2 cores to do other stuff. They share 8k of ram with the ULP. So you turn the ULP into a dedicated video controller. Yes esp32 has 3 cores.

[@Spritetm]

@@TheBodgybrothers Not sure if you want to... the ULP is a bit unwieldy. Better to use I2S to drive the panel using DMA; that way the sending of data to the panel continuously is taken care of by the hardware, and all you need to do in your two cores is to poke the right bits in the memory region that is DMA'ed over to set the pixel values you want.

[@TheBodgybrothers]

@@Spritetm but I take it from this video that the communications is not i2s, and therefore some assembler on the ULP would be an elegant solution. Could do what Clive did here on he ULP with about the same complexity as Clive's code.

[@Spritetm]

@@TheBodgybrothers Ah sorry, I went a bit too fast there. The ESP32 I2S peripheral has some other non-I2S features tacked on to it, one is a parallel output feature that you can use to control random things like these displays. See www.esp32.com/viewtopic.php?f=17&t=3188 for code/demo.

[@gavinsmalley1513]

@@TheBodgybrothers I'm not sure if the ULP would have the power to drive the display. Plus running it off the second core of the main processor means it can be programmed in C or one of the existing libraries for these displays could be utilised. Simpler than writing custom assembler.

[@ahmetdokuz249]

How did you arrange the hup75 pins as input and 16f628a output legs?

[@GeorgeWMays]

Clive, I just had an idea. You could sell Big Clive air sickness bags on your online store. Charge extra for the autographed bags....

[@RoterFruchtZwerg]

I have a LED Panel that has a capacitor in series with the output enable to protect the LEDs from blowing if... I hope. Never risked trying it ;) The Panel has 18 lines, but the LEDs are on for only ~1/100th the time.

[@Futternutterbutter]

I had a strange thought, so if you had a LED panel like that and the LEDs are that size if you were to make a panel like that the size of a cinema screen and play a movie across the leds since its so large would you be able to resemble a moving picture from LEDs that large?

[@bigclivedotcom]

These are modules out of actual video walls.

[@TheBodgybrothers]

Thumbs up for not using a Rpi.

[@gtwinman]

Big Clive, been watching your vids for the past month now and had a thought... Have you (or anyone else) ever 'upscaled' an old ACME or NJD (other brands are available, but I have those handy at the moment) "Moonflower" sound to light type fixture to utilise any of the Chinese cheapo units you seem to be buying recently? It would be great fun to convert them and add DMX too, but I can't think of anyone else I'd like to listen to explain or disprove the theory than yerself :-)

[@bigclivedotcom]

The complexity in upgrading many of the older lights is that they were designed around a very small point source of light. It requires a different style of optical system to use the common large area high power LEDs.

[@gtwinman]

@@bigclivedotcom Thanks for the rapid reply. Guess I need to save the pennies & upgrade then.