Controlling Mechanical 7-Segment Displays?! How RS-485 and UART works! || EB#43

[@pauljackson2126]

That sound of listening to mechanical clicks of these displays and even hearing the clicks of relay array is always a pleasure to hear🙌

[@sarmadrafique4472]

More like a therapy.

[@joinedupjon]

Yep I'd be looking for excuses to add needless extra segment flips just to make it click - non numeric spinning wheel effects etc.

[@reggiep75]

Poly-rhythmic relay click patterns are enjoyable to hear.

[@bexpi7100]

if you want to see some mechanical display + relay awesomeness, proto g engineering made a cool thing: kzbin.info/www/bejne/qZyQkK2wpNuAfbs

[@MrQuanticox]

here is more: kzbin.info/www/bejne/qZyQkK2wpNuAfbs

[@sikkepossu]

He's getting more and more insane with that "I will see you next time" thing. :D

[@ArnaudMEURET]

Those punchlines gimmicks are usually the last straw that pushes me to unsubscribe when a channel’s content gets repeatedly disappointing... Not that it has been the case yet with GreatScott but I still would love if he got rid of that annoyance ! 🤯

[@PassiveDissimulation]

Arnaud MEURET I think it’s funny! At least it isn’t the same every time. It’s his catch phrase.

[@josephhacker6508]

This video isn't sponsored by JLC-PCB

[@Rainbow__cookie]

Reality is often disappointing

[@labiadh_chokri]

This video is sponsored by ALFAZETA

[@josephhacker6508]

@@labiadh_chokri It doesn't have the same ring to it.

[@hardikmonga]

Boring without JLCPCB commercial 😂

[@anonymouspuppy]

Hardik Monga I know

[@lemonglataitor2123]

How to stress out children taking a timed exam.

[@greatscottlab]

Haha true :-)

[@AnthonyGoodley]

Lol that's funny.

[@girishradhakrishnan2699]

Lol

[@Glasshopper]

Very funny 😂

[@rich1051414]

Gradually increase the volume, but slow enough to make the kids think they are going insane :) This is why I am not a teacher... the kids would need professional help after my class.

[@ZevHoover]

I can’t be the only one who starts twitching slightly every time he runs the highlighter over the black pen enough times that the black ink starts to run. Love your videos though man.

[@glennlawrie-smith8570]

Zev Hoover Yup.

[@glennlawrie-smith8570]

Zev Hoover Yup.

[@DarkThanosGr]

I scream NOOOO every time!

[@TheInCaver]

True!

[@gglovato]

ajjaja me too

[@izzieb]

These kind of displays always remind me of the old clocks and departure boards in Britain, under British Rail.

[@CTCTraining1]

Yes, I wonder which rail enthusiasts managed to nab them. They used to make very solid clonking noises indeed.

[@izzieb]

@@CTCTraining1 I'm sure many did. I have fond memories of the old boards at places like London Bridge, making the distinct sound as the boards updated.

[@SheeplessNW6]

@@izzieb those departure boards are called 'split-flap' or 'Solari' displays, and there are at least a couple of companies who will sell you a new one. Well, I'm not sure whether Vestaboard ever stopped being vapourware, but Oat Foundry are certainly shipping. If you google for 'split-flap display' you'll find various hobbyists who have made their own!

[@samuell.foxton4177]

The station clocks in the UK were these, not split flaps

[@hackerman7835]

PRICING FOR OCTOBER 2019: 7 seg modules: 9 EUR apiece for 1-99 pcs controllers: 21 EUR for 1-99 pcs 190 EUR for a bundle of 1x10 digits with controllers

[@marcinpkrysinski]

hackerman 7 Seg is 6.50 EUR for any qty...

[@marcinpkrysinski]

Solitary Midnight for limited time they sell any qty for 1000+ price which is 6.50 EUR

[@dwild92]

@@marcinpkrysinski any quantity 1000+.... Yeah that's not any quantity if it's over a quantity.....

[@PabloAymerich]

And to get a price you have to ask for a quote. :( why couldn't they put at least an MSRP or estimated price per digit? It would be good for them to offer a DEV kit for $XX dollars with 4 digits and uart board?

[@sarkybugger5009]

_If you have to ask, you can't afford it_ is the usual approach of companies like that. Screw them! They must be out of patent, so I'm sure there's a factory in China churning them out by the thousand, for a dollar or two a piece.

[@PabloAymerich]

SarkyBugger I felt that way exactly

[@StephenHoldaway]

Search for "ebay Ferranti Packard" on Google - I found it slightly cheaper to buy new-old-stock or used original displays. Alfa Zeta is manufacturing new stock of an existing design which is great for industrial customers, but for hobbyists the supply chain aspect doesn't matter. When I got a quote from Alfa Zeta in 2018, it was cheaper per unit to buy a dozen on ebay including shipping than to buy 500 new units.

[@hackerman7835]

to quote another comment: The pricelist i got when ive asked was 9 Euro for a 7 Segment without controller (as shown in the beginning) 24 Euro for a single digit controller (didnt ask for code to controlle it, wanted to use it as a base for my own design). And the Simple flipdots were from 4-12 Euro available. Just mail them, the reply was fast and informative when i asked some questions reguarding shipping and price. Hope this helps. Their page also shows some cool Projects they did with artists.

[@beware_the_moose]

@@hackerman7835 at those prices why don't they just put a PayPal button on or something! I'd buy!

[@Nathan0A]

I don't know why, but the highlighter smearing your ink really bothers me on some fundamental level. Great video though!

[@martincerny3294]

He does this on every video, it's triggering lol!

[@jagadishk4513]

Hi Scott, I am debugging an RS485 design-driven by raspberry pi, before coming to this video I was tired upset because it was not working and it was 3AM in the morning. In your video you mentioned that the baud rate must to matched, then it dawned upon me that I must modify it and it worked. I guess when your frustrated you mess up even the most trivial things. Your video gave my cluttered mind a hint. Thanks a Ton, Scott, never stop making these videos.

[@lptf5441]

I really want to commend you on a particular detail of your videos... the time and effort you take, as a non-native English speaker, to slowly and clearly pronounce each and every word in your video. So many videos from people who are non-native speakers of languages are almost unwatchable because of how difficult it is to understand what they are saying. They have poor pronunciation, they mumble, and they speak way too quickly. It can be hard enough for some native English speakers to understand other native English speakers from different countries, but non-native speakers are other level of difficulty. However your efforts are absolutely wonderful. All your videos are very easy to understand. Thank you for making the effort.

[@davidadams421]

Absolutely brilliant - glued to the screen! Your patience and commitment is inspiring.

[@stevenmorisset4307]

10 digits will never be enough for you GreatScott !

[@graphenepixel8231]

Billions of subscribers

[@GRBtutorials]

Yeah, when the human population reaches 10 000 million, he will need an extra digit. Until then, it’ll be good enough.

[@vectorchan5647]

Hopefully china starts making these. I'm not buying from a company that won't tell you the price without "getting in touch with a representative"

[@g00st62]

Thats basicly just another way to say "way to expensive for you and dont even try to buy them if you dont need at least 5000"

[@hackerman7835]

someone ITT commented the following: Just contect their [e-mail] email address. The pricelist i got when ive asked was 9 Euro for a 7 Segment without controller (as shown in the beginning) 24 Euro for a single digit controller (didnt ask for code to controlle it, wanted to use it as a base for my own design). And the Simple flipdots were from 4-12 Euro available. Just mail them, the reply was fast and informative when i asked some questions reguarding shipping and price. Hope this helps. Their page also shows some cool Projects they did with artists.

[@doublebulbing]

@@hackerman7835 they are cool but too pricey just to buy to play with

[@geomagpsz]

I'm afraid that most of the times it works this way with industrial products :/ every time I have to do research to purchase components for a project is the same, I have to send s thousand emails asking for quotes (Usually they answer back with a huge price xD)

[@alpagutsencer]

The soul of the Marco Reps is in us.

[@amirreza6526gd]

thanks a lot for talking about the RS-485, I wanted a simple with example video about RS-485 and your explanations were the best.

[@alanm.17]

This could’ve made a really bad ass 80s dashboard speedometer

[@Gamezone-sd3er]

Well I can use it as notification for great Scott video upload

[@greatscottlab]

Correct :-)

[@otm646]

We use a large 3 inch set of mechanical displays on our racing sailboat for important data. It's excellent, low power and most importantly doesn't have the visibility issues like LCDs with polarized sunglasses. Old tech but still the best in some applications.

[@cabasse_music]

your vids are the best, man. can't believe i hadn't found your channel sooner

[@Clark-Mills]

First saw the display and thought... I could optimise that code by storing (buffering) the state of every segment and then just flipping the segments that have changed. Then I look at 4:06 and realise that the code is already optimised. Nice.

[@anycatdessai]

Liked the new fusion way of project and electronics basics video in one. Makes it quite interesting.

[@greatscottlab]

Thanks for the feedback :-)

[@StreuPfeffer]

Ive found the company a while ago through another YT vid. got myself a couple 7 Segments and some flipdots. Also got a single RS485 segement, didn't get to them unfortunatly yet. Thanks for makeing it more clear how they are driven though.

[@MrKugelkopf]

How much did you pay for it? And is there a shop?

[@felixwurm1467]

i think you have to contact them

[@StreuPfeffer]

@@MrKugelkopf Just contect their [e-mail] email address. The pricelist i got when ive asked was 9 Euro for a 7 Segment without controller (as shown in the beginning) 24 Euro for a single digit controller (didnt ask for code to controlle it, wanted to use it as a base for my own design). And the Simple flipdots were from 4-12 Euro available. Just mail them, the reply was fast and informative when i asked some questions reguarding shipping and price. Hope this helps. Their page also shows some cool Projects they did with artists.

[@MrKugelkopf]

@@StreuPfeffer thank you!

[@engineer0239]

Funny. I worked with Modbus Commands sent from a PC that got converted to RS-485 in my holyday job. I was controlling an Axis that moved a camera for Image recognition. I was coding an UI for it and now you´re making a video about it. Nice.

[@andrewkieran8942]

Another great topic, but I missed something. In one of the the diagrams, one end of all of the magnets in a digit are connected to a common source, and the individual segments are grounded by a darlington transistor pair. How do you switch between the two states; segment displayed or segment not displayed? Removing the power retains the existing state so don't you need to apply the power for state 0 and reverse the polarity to select state 1? How do reverse the polarity in this case without an h-bridge?

[@raykent3211]

Me too. I guess he used Darlington pairs to drive leds that needed more current than an ordinary logic chip can provide and he guessed that this was done here. But, as you imply, current can only be passed in one direction through a darlington pair and the muxing won't work. Most likely there's a number of mosfet H-bridges involved. There's a lot of chips on that driver board!

[@valshaped]

You might be able to get away with pulling the common line high and pulling only the electromagnet you want to load low? I'm not sure.

[@danielvalle3789]

Pondered the same thing! Figured I missed something (which, I obviously did but still happy I'm not the only one lolol.)

[@MrJuuustin28532]

You are THE BEST at this out right now. Thanks for all your work. Awesome! 👍

[@bharathr2871]

More than college education your channel gives me more information.

[@rafaswierczynski]

So cool those displays :) As always - nice video! And sound of switching.... lovly...

[@paulturner5769]

That doesn't explain how the drivers supply reverse voltage / current to the segments you want to turn from ON to OFF though.

[@popcorny007]

Presumably that is handled by the controller board. He is just programming to get a serial output.

[@paulturner5769]

​@@popcorny007 I was referring to the explanation of turning segments ON at 2:58 to 4:03, It is NOT like multiplexing LEDS which turn OFF when there is no power, these segments retain their state until power is applied in reverse.

[@labiadh_chokri]

Yes every segment must have a H bridge or be connected between tow Logic output that can source and sink the appropriate current .

[@andymouse]

I must say, those displays are quite charming.

[@ats89117]

It's a good thing they sent you a 10 digit display so that it can count up to ten billion subscribers. You never know!

[@Gideon_Judges6]

This is some heavy artillery compared to just a 4511 or similar 7 segment decoder, but then again you would need multiple (10x) plus some kind of transistor as I suspect those coils draw more current than the typical LED seven segment.

[@graphenepixel8231]

I thought the same thing.

[@dj_paultuk7052]

RS485 used to be really handy in the pre-wifi days as you can run it really long distances with no loss of signal with a data speed of 115k. A company called Lantronix also sell a Ethernet to RS45 server device (UDS10), so you can drive RS485 on a ethernet based network.

[@resneptacle]

Still being used in the show and theater industry for the DMX lighting protocol

[@derekchristenson5711]

Neato! Thanks for showing this in action.

[@keithking1985]

I have to say it is satisfying to look at.

[@crazyivan030983]

And now you have red "black" highlighter... :) super video :) greetings from Poland :)

[@diyexplorer8728]

I want to use this as a clock on a school library. Great video!

[@dieterdodel5265]

Machst Sehr gute Videos. Einfach erklärt. Gefällt mir sehr💪🏽

[@graphenepixel8231]

I love that sound.

[@wtf6892]

Thank you for making this kind of videos it's priceless!

[@pjshots]

I need those things in my life! So functional and direct.

[@jamest.5001]

Kinda cool retro style tech, reminds me of the old alarm clocks!!

[@mathiasbackof4993]

Oh man finally a real thumbnail

[@dr_stoned_4207]

Finally a new sponsore!!!!!!!!!

[@theteenageengineer]

The control board seems a lot like a DMX controller for entertainment industry lighting, big Clive has some great videos explaining it. But DMX uses RS-485 to be able to control up to 512 lights and the 2 RJ-11 ports on the controller board is where I got this connection from because for DMX there is always 2 ports on each light so you can connect multiple in a chain.

[@sjm4306]

Alpha zeta is great, they sent me some displays to make a sub counter with as well. I designed my own controller as I wanted a challenge and ended up open sourcing the design.

[@MikeysLab]

Love this display, but the companies site does not have pricing or a way to order :( would love to use these in a project on my channel.

[@tushar673353]

you did really lots of work on this project

[@aisaya-ana]

Very Nice. Also your explanation lead me to understanding another things as well. Thanks.

[@unperrier5998]

The three digits on the right hand side (lsb) mechanically switch more often and hence will wear before the most significant digits. They must have thought of that and allo you to replace them or swap the 3-digit module with the msb one.

[@brane3698]

segments have no mechanical linkage, they are controlled with electromagnets, so there is nothing to wear out, at least not that soon...the manufacturer states segments are rated for over 250 million operations

[@unperrier5998]

@@brane3698 250 million operations, that's plenty but it's probably less due to dust and dirt.

[@unperrier5998]

@oH well,lord! if you prefer.

[@Miata822]

OK, that's pretty cool. It just seems to me these displays call out for an analog driver. Thinking about how to do that.

[@geomagpsz]

I've just unsubscribed and subscribed again just so you could hear the noise of it. Now it's time to do a cool enclosure for it with neopixels ;) Keep up the good work and smooth editing. Your channel is really fun to watch and inspiring! Greetings from an electrical engineer in Munich :)

[@GRBtutorials]

Unfortunately that won’t work, as it takes a while for KZbin to process it.

[@sasodoma]

@@GRBtutorials Also, it seems to grab the public data, which is rounded to two decimals. In his case that's rounded to the nearest 10 000.

[@honzapat]

KZbin changed, you now need to be authed as the creator(some app in gcloud console probably) to get it precise.

[@pileofstuff]

@@GRBtutorials It also won't work because youtube now rounds off the subscriber number...

[@pileofstuff]

@@honzapat Even with your own API key, you can't get accurate sub numbers via the API. Only from the creator studio, which can't be pulled into a device like this.

[@Enigma758]

With source driver common to all electromagnets, and sink driver to each segment, it's not clear how the coil polarity reverses in order to reset (darken) the segment.

[@reggiep75]

6:55 - This is like the XLR standard in the music industry for professional balanced audio facilitating levels of noise removal. People think 'Hmmmm' to begin with and then 'Aaaahh' when they understand the process of the inverted signal to isolate the noise and then remove it from the final signal.

[@JDanielGamerXD]

And don't forget that stage lights use XLR too

[@reggiep75]

JDanielDroiidXD - Depends on your pinout (anything from 3-7) but the good thing about XLR is it's scalability lending itself to a shit load of functions :-)

[@anyfinity]

1:48 - 1:52 that's a great idea!

[@giotinez5996]

I learn a lot with ur videos even many of them are for avanced dudes. Thanks brother

[@thexpto51]

Very good! Really Nice Work! Congratulations!

[@AnthonyGoodley]

When them new fangled 7 segment LED displays are too high tech so let's take it back old school.

[@AnthonyGoodley]

Like I think these are very cool and all but it seems like a lot more work to get working as compared to 7 segment LED's. Reminds of those Airport displays that click to show arrival and departure times, gates etc.

[@romandirscherl151]

Please Upload a Video in Twitter where i can hear the clicking sound It sounds so awesome

[@greatscottlab]

There already is one on twitter.

[@ZeroMass]

Another interesting video. I look forward to your uploads 😋🍺

[@greatscottlab]

Thanks :-)

[@d23rfd3gfjhjhgfdze]

This channel should have more Subs.

[@StickySli]

I'm currently learning how the USART works in the Atmega328p in my ICT Engineering degree. The catch is we're learning to program the microcontroller in Assembly. We've yet to learn C and other languages. Assembly is pure masochistic.

[@jcgo16]

The sound that it makes so.........gooooooodddd

[@DIYPINOY]

Great project. Great scott

[@agarceran]

I personally preffer the look and sound of the Split-Flap displays, but this looks interesting and are quite a lot simple.

[@haroonsyedmohammed8430]

Your videos will be exciting!

[@stjepansavic4485]

That sound for mi is beautiful

[@arthurbondar4881]

no need for multiplexing, a simple shift register and a couple of latching ICs will allow you to connect any number of those displays...

[@Loundre3]

What about the drivers for the electromagnets?

[@arthurbondar4881]

those too ofc

[@andrejwalilko634]

Scott is now limited to less than 10 *billion subs

[@SlykeThePhoxenix]

Well obviously he's gonna drop the LSB when he hits 10 mil.

[@tomf3150]

More like 1.999999 billion.

[@mountainpass4255]

7:44 "If we ignore the letter S" Doesn't ignore the letter S

[@BlackXeno]

Time is gone when I could see 10 minutes of GreatScott without additional 2 Ads in the middle...

[@popcorny007]

At least be happy he can find such extremely relevant sponsors. Imagine him being supported by Blue Apron...

[@srinivasraor770]

That was amazing project you took scoot i just loved it.

[@IvegaEletrônica]

Muito legal esses displays.

[@AmeshaSpentaArmaiti]

They look really nice

[@kirbymia6209]

This is pretty interesting especially since we just started messing with USART for our microprocessors course. I might make one of these some time.

[@sudhanshushekhar6920]

That's nice display 👍👍👍👍👍

[@EasyElectronics2412]

one of the awesome videos i have ever seen!!! :)

[@movax20h]

Well. But how these ICs reverse also polarity of signals going to displays to turn segments off?

[@greatscottlab]

That is a good question. I assume it might have something to do with the tons of diodes soldered to the back of the electromagnets. Not sure though, I did not dig that deep.

[@triplexdread]

I was waiting for it to hit 1 Billion. Dammit

[@AsymptoteInverse]

I really love electromechanical displays.

[@blackturbine]

Time to go to sleep Subcriber counter: are you sure about that

[@creazychannel]

2:03 this vedio is not sponsored by JLC PCB.

[@lukaszpodgorski]

Great Video Great Scott

[@galier2]

The twisting of the cable was not really necessary. We used it always on flat cables with 15 Pin D-SUB connectors with speeds up to 38400 without ever having any issues even in hostile industrial environments. The only important thing is that the differential data lines are not too far appart so that induced noise is the same on both lines.

[@arduinohub5957]

I will use some multiplexers and transistors to drive this (without understand the whole mess) :D

[@sligovolts]

It's a lot harder than it sounds. Look up on KZbin, there's some videos of EE driving similar dot matrix displays

[@260830107]

to flip a segment it needs a >200mA pulse in 1 direction and un-flipping needs a current pulse in the opposite direction, you'll probably need something that has a push pull output

[@surajsingh4477]

nice video teacher, always waiting for next, keep up, thanks

[@mgfails9274]

9:29 Did you set on fire your probe tips?? They are looking like they were melted

[@greatscottlab]

Yes, it was an accident.

[@moclan582]

Hey, wich Multimeter do you currently use? Would you recommend it? And do you maybe have a recommendation for a meter for around 100€?

[@danielvalle3789]

Orrrr, ....just tell the man!!! Somebody need a snickers perhaps???

[@danielvalle3789]

(

[@moclan582]

@@danielvalle3789 ikr I can't find the video

[@Uko_]

I think you forgot to explain the ground reference problems of RS-485 or UART. For example, the maximum common mode voltage of A and B inputs, when to use isolator, and so on. Basically, the ground connection in differential signals .

[@GewelReal]

Another cool thing that I have no time nor money to rebuild

[@jansaljaj3042]

They are probably not driven that way because of coil resistances which would activate other digits. Watch Marco Reps's video about his clock, he had this problems.

[@LordPhobos6502]

3:00 - what is the source IC used? It's very hard to find good source ICs! :(

[@Cinemaaereo]

It's not a hand drawer, it's a fake hand plotter with really great font! 😁

[@vibhanshuchandwani4527]

Hey, what about your wind turbine that you posted on facebook

[@Raismans]

Now we just need Nixie tube display control video :)

[@blink11101]

This video was awesome!

[@HboskO1982]

Modern nostalgia :)

[@cquiles386]

I hope you make a video of you making a custom enclosure for this!

[@startobytes]

Hello, can you make a sr latch with transistors ?!

[@sentien13]

I use RS485 basically daily, the moment I saw you writing code for the Nano I was instantly going 'nope, nope, nope, nope!' in my head. Whilst I fully understand the difference it would have been useful to explain WHY the Nano does not support the 485 standard.

Vince Osborn I am also curious about this.