LED Displays with Arduino - 7-Segment & Dot-Matrix
ฝัง
- เผยแพร่เมื่อ 10 พ.ค. 2024
- Use both 7-segment and dot-matrix LED displays with an Arduino.
Article with code: dronebotworkshop.com/led-disp...
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Yes I know they have been around for over half a century, but LED displays are still a great choice for a number of applications. They are inexpensive and have great visibility and durability.
Today we will be working with both 7-segment and dot-matrix LED displays, in single and multiple modules. I’ll show you a number of different configurations of LED displays and how to wire them up and code for them.
I’ll be using an Arduino Uno for all the experiments, however, the information is equally applicable to just about any microcontroller.
Here is the Table of Contents for today's video:
00:00 - Introduction
01:34 - LED Displays
07:37 - Single 7-Segment Display
15:37 - Multiple 7-Segment Displays
24:27 - MAX7219 8-Character 7-Segment Display
32:41 - Dot-Matrix Display Module
42:57 - Conclusion
If you need the code I used in the examples, just check out the article on the DroneBot Workshop website at dronebotworkshop.com/led-disp...
Hope this video lights up your life!
:)
Bill - แนวปฏิบัติและการใช้ชีวิต
Hi everyone - It's come to my attention that there has been someone masquerading as myself, responding to some comments here with a link to a Telegram chat to win a prize from me. THIS IS A SCAM, I am not holding a contest, nor do I have a Telegram account. PLEASE DO NOT RESPOND TO THESE MESSAGES!!
It's happening on a lot of my videos, I'm taking steps to remove them manually, but as I have 162 videos, it will take some time. If you do run across a suspicious comment, I would appreciate you letting me know at info@dronebotworkshop.com.
Thanks!
Bill (The real one!)
You and the other makers here on TH-cam are some of the most important people in the world, thank you Bill
I couldn’t agree more.
True, he deserves more views for the quality of these vids
As always very clear and simple explanations. It never sounds as if you are talking down to people who are new to the concepts that you show us. You seem to have a genuine desire to share your knowledge and excitement at your own discoveries. Always much appreciated.
Hi Bill,
Thanks for this great video--and for ALL of your terrific work. Everything you do is extremely easy to follow and valuable! You are truly a gift!!!
Great and thorough. I made a multiplexed clock the hard way. This is a bit easier to manage. Thanks for all the time you put into this.
I cannot thank you enough for the information you share and the way you share it. Thank you, thank you, thank you.
I really love your lectures and the way you teach
Hi Bill, I always learn a lot from your demos. On the dot matrix example you show the CS connected to pin 3 on the Arduino but the code uses pin 10. Thanks for the great demos and lectures. You're the best,
I always leave these videos happy. I learned something new and useful every time. Thanks, Bill!
This could not have been more perfect timing! :)
Just requested to be a member of the forum. Greae respect in all your videos - I understand every single word you say and I am looking forward to learn a lot of new stuff in future. Your videos are for all levels of interested younger and older people. You remind me of all the teachers from my training period who were understanding, took the time to speak clearly, and treated students with respect. Keep on going!!!
Been playing with these for awhile they have their place. Great video as always
WOW, just what I needed! Just received some 4 digit 7 segment displays!
Amazing video! Exactly what I was looking for
So many new and updated libraries! Thanks ever so much.
Thanks for your lectures; you garnish your teachings with history and Acronym explantion which it very relatable. Thanks so much
Thank you Bill for your awesome videos. I learn a lot from you every time I see them. Greetings from Bogota.
As always amazing and helpful.
Usually I use seven segment display with shift registers.
I know it's not the best way but you don't have to worry about the multiplexing time or flashing.
This is the first video that made it super easy to understand how arduino works. Thanks for making me understand. If others explained it this easy more people would use and buy the arduino boards. Thank you for sharing...
Thank you very much for your excellent tutorials from those I've learned so much about Electronics. The world is a better place with people like you, keep up man! ❤❤❤ Sattar From Iran.
Thank you so much for this video! 🙏
I was eagerly waiting for a video on these displays. 😀
Oooh this was useful and gave me lots of ideas! Thanks for the clear and easy to follow explanation too.
Bill I am Tahir Mushtaq from umt Pakistan. Highly thankful to you. Your lectures help me a lot in teaching dld and iot. Keep it up. It's a wonderful work. God bless on you and your team bill
Cool! Thank you for pointing this out (dot matrix)!
A very educative episode. Loved it a lot. Thank you.
Thank you for this in-depth explanation
Brilliant Stuff, really well explained and the graphics are excellent, thank you
It is always nice to hear somebody who knows what he is talking about.
As usual first class information thank you very much !!!
Thank you for another thorough video explanation
Very well explained, thanks for sharing.
Your the boss man! I had so much fun making my LED Display work!!
Great video, the project we have been waiting for..thanks
Great video as always. you always give us such in depth information on the projects you choose. I would have liked to see you create something for this video with the alpha numeric led displays as well. All in all great video and thank you for all your hard work!
I noticed an error in your video animation for the LED Matrix. You define CS pin on the display connected to Pin 3 of the Arduino in the animation. But clearly in your video the chip select is on Pin 10 as shown in the Parola Library demo code.
Thank you for that great video. Exactly what i was looking for ! 🙂
Very informative. Thank you!
Always very interesting, very simply a well explained definatly valuable. From Egypt with love 👍😊
Don’t forget the HT16K33 based I2C based drivers. I have used Adafruit 4 digit displays with their backpacks on 2 projects, one Arduino and one ESP32 and really like them.
7 segment displays have 8 pins in use, 7 for the segments and one for the dot. 16 segment displays allowed the designer to print letters on the displays but they were less common due to requiring more pins. RGB and RGBW dot matrix displays are a different ballgame, the older displays used a common cathode or common anode so driven from 8 rows and 8x3 columns however with the advent of addressable RGB and RGBW LEDs, these LEDs have a built in IC that you simply provide power to the LEDs and then chain the DI and DO pins together which allows you to access the particular LED in the chain. However, the downside being that each LED takes up memory space to work with, not too much of a problem for the ESP32 but can be a problem for the Arduino AVR based microcontrollers.
Very cool, cleared lots of things up. I was just thinking how would one go about making their own led display out of led's , and perhaps draw text / images or animations on it but assumed the arduino was not suitable becaause of its limited I/O. Then I saw a video of a guy who did just that, 7x10 led display segment modules that intereconnect with other ones. Theres 70 leds on each and all controlled by a micro controller with only 17 i/o pins. He used seperate transistors in the mix which i think was key. The IO was for rows and column, not seperate leds, 7 for the rows and 10 for the colums so i assume somehow the transistors let him select sepearte led's. Im a newbie so i didnt understand his schematic and he didnt offer much explanation, but its cool to know you can actually controll more led's then the i/o pins you have avaiable, even if it means seperate hardware like a bunch of pnp transistors. I only wish someone could explain so eloquantly like DroneBot Workshop as to how. Here's a link to the video for anyone interested th-cam.com/video/rVm0a2LOSjk/w-d-xo.html
You are “The Best” thank you!
I want to thank you for sharing your knowledge so well. I'm learning a lot. Thanks.I want to thank you for sharing your knowledge so well. I'm learning a lot. Thanks.
Great tutorial! Very nice video 😀
Wonderful as per usual
Please note at 42'22" there is a line in your code. Line 29 HARDWARE_TYPE. You need to change this from PAROLA_HW to FC16_HW. If you make this modification then the PacMan animation will run properly. A bunch of those examples included with the library default to PAROLA_HW, and most users will benefit by changing this to FC16_HW.
@5:00 - on top of that: each segment can have a bit different luminance and forward voltage - as a rule one should not put LEDs in parallel for this differences in forward voltage. One more thing: if you put 1k resistor in common, you will never have more than 5mA in total current (actually much less even from 5V Vcc) while individual resistor being much smaller will allow more current to flow / brighter segments. So it seems to be a bit counter intuitive why > 820-1.5k Ohm for common connection (1 resistor) vs 220-470 Ohm for individual segments.
my understanding, using 820-1.5k ohm on common connection is not correct. You should just use same resistor (ie. 220-470 ohm). How the code works is it cycles through segments to switch it on. It does not switch all segment the same time. that's why in video, using 1k resistor will reduce the brightness, as you mentioned, the LED only gets very little current
@@apratube that makes sense - it refreshes each segment quite fast. Otherwise there would be no way of having multi segments with 1 common anode/cathode.
If the Pacman animation had started on the left and cascaded towards the right as it went from one device to the next, then it would have looked a little more consistent. Probably only a small code change is needed.
Very helpful to understand. Thanks
Correction: NIXIE displays use neon gas and require a high voltage power supply. They do not use filaments. Usually they have one cathode per digit so a typical nixie would have 10 cathodes to represent the digits 0 through 9. The common anode connects to the high voltage supply of about a 170 V DC.
Referring to the number-shaped cathodes in a nixie tube as "filaments" is an acceptable use of the word in its generic sense. It's the same way the word is used for the plastic feed stock of a 3D printer. That's called filament, too. A few definitions from Websters-Merriam: "a single thread or a thin flexible threadlike object, process, or appendage" and (more to the point): "a cathode in the form of a metal wire in an electron tube." The dictionary also includes the more-commonplace definition, "a tenuous conductor (as of carbon or metal) made incandescent by the passage of an electric current," but it is by no means the only definition. The word filament is from the Latin word filum, which means "thread."
@@tcarney57 I think Bill was confusing Nixie tubes with INCANDESCENT displays, which have a filament for each of the seven segments. When current flows through a segment filament it glows just like a filament of a light bulb. Nixies contain ELEMENTS, in a glass bulb with a rarified gas such as neon. A high voltage applied between two of these elements causes gas ionization and the production of light. Both types of displays require a glass envelope with the air removed. LED displays do not require that.
Most thorough, yet concise content. Thank you lots. Do one on laser sensors next? ^_^
This was very useful, BUT an example of i2c & Temperature would have been a nice addition. Thanks!
muy buen video amigo, saludos desde chile!!!!
Excellent!
Thank you for sharing. Greetings from Karachi, Pakistan.
Helpful video 👍
Awesome stuff. More options for providing information to users, much like your e-Paper display you recently provided. I did notice that the Pacman example doesn't seem to be scrolling across the LED matrices properly. The Pacman should move from one side to the other chasing the ghost, but it seems out of sync. I suspect this is a problem with the code sample, and not how the LED matrices are configured since your "Welcome to the Workshop" msg came through fine. Great video as always. Appreciate electronic tutorials like these.
HERE the #solution for the #PacMan error in the sketch;
It is not really an error. Just the wrong hardware connection
default hardware = #define HARDWARE_TYPE MD_MAX72XX::PAROLA_HW
Opt this one out, and then;
Choose one that fits yours;
#define HARDWARE_TYPE MD_MAX72XX::FC16_HW
#define HARDWARE_TYPE MD_MAX72XX::GENERIC_HW
#define HARDWARE_TYPE MD_MAX72XX::ICSTATION_HW
Great video
CheerS Drone Dude. YFS, GB :)
Very nice video
Thank you
Hi Bill I really enjoy this project with the 7 segment displays and the dot matrix. I ordered some displays to try this out. Is there a limit of how long the wires connecting a DHT11 temperature sensor? I want to show the temperature inside and outside on mine. Thank you Don
Your so cool man
I once designed a digital clock using 7-seg LEDs back in the '70s. I came up with a neat trick; to make the colons between hours, minutes and seconds I turned each tens display for minutes and seconds upside down and reassigned the pins to get the numbers to display correctly, and that puts the decimal points of two displays between the digits, giving you free colons.
Anyone with any aesthetic sense will hate this "neat trick".
@@futu1983 It does admittedly make a disproportionately tall colon, but it's free, and anyone with any aesthetic sense wouldn't likely be using 7-segment displays anyway. :)
Thank you Bill,
I have seen these displays for decades and never knew how they work. I was wondering, you used 1x4 and 1x8 dot matrix displays. Can you use 2x8 or 4x16 etc?
I always says your intro audio is awesome..
You can use 1 220ohm resistor on the common and loop through the segments, having 1 segment lit at a time at high frequency!
Wow great presentation👌👍, learnt a lot on Arduino, thanks a lot 🤝, can I try these on Nano?
it seems like the pacman example is going the wrong way :)
i've seen similar issues with other examples, probably you need to use some "rotate" setting to turn that 180°
Hi Bill, I'm sub’d to both here and website, if I may say just one thing, besides the awesome videos you do, but I think if you were to put a shade of some sort over the front of the displays, ie: smokie plastics or similar, it would be more readable for people viewing your channel, just a suggestion mate. Keep up the awesome work mate. 🤙🏼🇦🇺
Mantap..
Good tank's very much Master.
Hi, Bill. I'm part way in and you reference the use of seven segment numbers in telegraphy. Can you please elaborate on such as I'm curious. I had to learn to transmit and recieve morse code (as used in telegraphy I thought...?) for my ham radio licence and I cant recall such. Great video ThankYou!
😀 good job.
Nixies floresce/excite neon/argon/mercury gas between an anode and cathode. No filaments.
VFD displays use a filament heater and otherwise function like a vacuum tube.
Numitrons are all filament based and looked similar to modern LED displays. Some ran on 5vdc and could be driven using TTL chips.
Panaplex displays, which looked like 7seg LED packs, were nixies in every sense. High voltage needed, no filaments.
There were other numerous ways to display numbers back then. CRT based displays, dial light (optical), etc.
Thanks!
You are most welcome, and thank you as well.
thanks
Great!
Great video! Just a question, i still have doubts about the wiring of the colon in the middle. I count 12 legs, 8 for the segments + 4 for the common anodes/cathodes. How can i wire the colon LEDs?
Thx a lot god bless you , hoply make a prjoect with ttgo sim800L device
Nice video. please make a video on PID Controller by Arduino. thanks
So I was wondering if you could demonstrate a project with a Arduino which utelises all the available pins. maybe doing multiple tasks at once?
Nice ! The pacman example seems strange because it's the wrong display type in the code I think...
You should add a green transparent cover to increase the contrast.
Pacman is running in the wrong order screen wise
HERE the #solution for the #PacMan error in the sketch;
It is not really an error. Just the wrong hardware connection
default hardware = #define HARDWARE_TYPE MD_MAX72XX::PAROLA_HW
Opt this one out, and then;
Choose one that fits yours;
#define HARDWARE_TYPE MD_MAX72XX::FC16_HW
#define HARDWARE_TYPE MD_MAX72XX::GENERIC_HW
#define HARDWARE_TYPE MD_MAX72XX::ICSTATION_HW
What editor/environment are you using for writing the schematics?
Hello thanks for your videos. Can I ask a question how is it possible to connect the 3 pins of MAX7219 (DIN, LOAD, CLK) wirelessly to arduino board? Thank you.
This time the shift registers aren't used (74HC595). Some people use CD4511 on 7 segment display too.
Hi. Can you send me link to your shift registers and coupled with 7 segment display tutorial? I'm interested in reading dc voltages between batteries in series. Thanks
How are you butting multiple 8x32 units together? My thought is to solder a straight header pin on the other end and use jumper wires but not sure if it's going to fit that way with the wires and headers having to go between the LED matrix and the circuit board. My other thought was to desolder the 90 degree header and use straight headers on the ends that butt together, that way the jumper wires would be on the bottom and out of the way. A 90 degree female header was a thought but wouldn't let them butt together properly. How did you do yours? I have the same style where the 90 degree header pins would go between the LED matrix and the circuit board. Thanks much, love the stuff you do and I always check your videos for awesome projects.
Ron, Did you get an answer? I am trying to resolve the same problem myself. I have 3 8x8 modules and short of Soldering the output of one to the input of another, I can't figure it out.
@10:01 You said: "Common Anode Display" but you are actually using common cathode display connecting COM pin to GND!
It's just my OCD, I had to point this mistake out.
wonderful tutorial but my letters and / or numbers are reversed, i.e. mirror images. and i tried 2 different displays
Make a series with microcontroller
Tak!
Thank You!
I want to use a Raspberry Pi Pico
do you think I will have trouble since it runs at 3.3 instead of 5
Hey Mate. I´m a new, but big, fan of yours. As a Arduino-beginner as me, your videoes are really helpfull. I am having problems with the 8x8. Just like Vic Dohar discriped with the code for Pac-man, it´s running the wrong way, and i can´t code my way out of it. any idears?. thanks. keep doing what you do, you are a geniues.
HERE the #solution for the #PacMan error in the sketch;
It is not really an error. Just the wrong hardware connection
default hardware = #define HARDWARE_TYPE MD_MAX72XX::PAROLA_HW
Opt this one out, and then;
Choose one that fits yours;
#define HARDWARE_TYPE MD_MAX72XX::FC16_HW
#define HARDWARE_TYPE MD_MAX72XX::GENERIC_HW
#define HARDWARE_TYPE MD_MAX72XX::ICSTATION_HW
Is there a way that I can make the 4 digit display show letters instead of numbers? I want alarm to switch from 05:59 to 4 letters (the display will be installed into alarm, to imitate the clock). Please let me know if it's something that I can do with this display.
nice
How do you choose the pins to use? Why not start at 2 and work the way up?
if I want to use three different 4 digit seven segments in one PCB it self, for display three different parameters how I should do this ?
Is there a way to add to the 7 segment library. I would like to add the Letters P and U
sir could we not rely alwats in a library program si that we could clearly understand hardware software operation thouroughky,thnx.
what software do you use to simulate the arduino ?
How to modify parola scrolling sample to use Bluetooth for text input instead hardcoding it?
Anyway, My dot matrix 7219 works properly with parola library (with FC16_HW setting). But when I use LedControl library, I get mirror image problem.
Anyone knows how to fix the problem?
Common Cathode LEDs for the MAX7219