How to use LED seven segment display and calculate its resistors value

[@3sgtecelica]

I've watched about 10 videos about these types of displays. Others just tell you what to connect where with little explanation. This is the best video I've seen by far. You actually explained it instead of just telling me what to do with no explanation. Thanks. You are a god among men.

[@robojax]

You are welcome. I am please to be helpful. You are a good-hearted person.

[@tonyfillery6103]

Thank you for taking the time to explain how 7 segment display functions.

[@robojax]

you are welcome. :-)

[@pixelkoucholo7462]

Really helpful But how to understand a 7 segment is cathod common or anode common ? and How we can find that pin out of 7 segment ?? I couldn't find a thing same as that on net too

[@robojax]

Thank you. I believe in explained this in the video. Watch it again.

[@WispYart]

Ah! Exactly what I am looking for! Thanks :)

[@robojax]

Glad I could help!

[@Enigma758]

At 20ma per segment, you don't want to light too many segments at a time if you are using an arduino, since the maximum current that can be drawn from an output pin is only 40ma. If you want to control these from an arduino either power the display from an external power supply or multiplex all of the segments such that only one segment is on at any given time.

[@robojax]

each segment is connected to single pin so there is no issue with that. And yes external power is the best option.

[@Enigma758]

​@@robojax That's true in your example, but if you want to create a working two digit display with an arduino this way, you would need 16 digital pins, but the arduino only has 14. So practically speaking, that's a problem. For multi digit 7 segment displays, It's typical to connect each digit's common to a unique I/O pin to select the digit. Also each segment of the digits are wired together (e.g. digit 1's "a" segment is wired to digit 2's "a" segment and so on...). Then 8 additional I/O pins are uniquely connected to the segments a-g, and dp. The pin count is now at 10 (still quite a few, but workable). Of course one could reduce pins further by multiplexing the I/O (e.g. via shift register), but in any case, once you build a practical circuit, it is then possible to turn on multiple leds and run into problems which is a trap beginner's can fall into. Hopefully, my point is clear. Thanks.

[@robojax]

Here is a solution for that kzbin.info/www/bejne/oV7JZ5-trLqHd9U or this kzbin.info/www/bejne/iGbWpZhriq2gh80

[@anantkhanna4954]

is port 3 and 8 connected? so if I put a battery on 3 and 2, 'D' would light up? and same if i connected to 8 and 2? (i have a common cathode display) One more thing, is there a formula to get the resistor value? (sry didn't really understand how you calculate it)

[@robojax]

Yes 3 and 2 or 8 and 2 will turn the D . for your second question ,with 100s of videos, I had to watch to answer your question and Sure enough, I have answered your question in the video for formula. You must have escaped. I have explained so you fully understand how to calculate the resistor. Thanks

[@technologyexplorercameroon7177]

I would like to understand at the beginning of your video you have use the led of segments without the resistance and by the end you say that each segment led need resistance .Could you explain me please ?

[@robojax]

I mentioned that seven segment display needs about 2V to turn ON. yes you don't need resistor if you connect directly 2V to the segments. We use resistor to divide (reduce) the voltage. There is another video on Seven Segment here kzbin.info/www/bejne/eIGnk4hqpaeGrNU

[@chazedigitalagency8367]

Before watching this video, I already roasted two of my 7-seg displays 🤣 Thank God I now understand how it works in practice 😌. Thank you. You're a good teacher 💯

[@shvideo1]

How do you display two different numbers on the 2-digit one where the pins are shared? Same numbers are easy like 33, but how do you display 45 for example? Thank you for this video!

[@robojax]

Hi, it seems you missed the most important part. Each display has its own common. you turn on common 1 to display 33 and then common 2 to display 76. please watch this video again.

[@shvideo1]

@@robojax But the 2 digits share the same A-G pins, which means that they cannot be on at the same time to display 2 different digits. One KZbin video said that you have to turn each digit on and off fast enough to fool the eye in seeing both digits at the same time. Is that correct? I think it makes sense. It is a compromise between less pins but more circuitry. Your video did not explain that so I didn't know. Thank you for your reply and the details in your videos. They are great. Keep up the great work and have fun!

[@diogob003]

I have the same issue. I don't know how to display different numbers, like 41

[@TeknikYT]

very useful, thanks for the information

[@robojax]

You are welcome.

[@pnmpl]

Awesome video!! Thank you for your time and experience .

[@paulking283]

The best explanation and demonstration.

[@robojax]

I am glad you like it. Thanks.

[@zer0b0t]

I wonder why I can't use one resistor in the common, that way you save yourself a bunch of resistors :)

[@robojax]

because one resistor will create voltage reduction that is enough for one segment. We have 7 segment and each will be ON or OFF independently. If they were all on like showing the digit 8, then we could use one resistor. But because the display is to show different digits, it must have separate resistor in order to lit properly. You could use one resistor, but at different digits, you would get different brightness which is not good.

[@zer0b0t]

Right, that makes lots of sense :)

[@waqqaspatel9113]

What is input voltage to this circuit?

[@robojax]

voltage is 2V you can see it at 04:16

[@VictorNolochemical]

Thanks brother this was very very very helpful. THANK YOU!!!!

[@robojax]

You are welcome.

[@androcci]

I want to make a 3 digit 7 segment display voltage generator with a voltage indicator. but I want the display to be from 1-5VDC being 1VDC be 0% and 5VDC be 100% anybody know how to go about or they could link me an article?

[@robojax]

This might help you. kzbin.info/www/bejne/eqbEnp2iqNmCga8 and for voltage measurement, use this video kzbin.info/www/bejne/ipOvlXSHpapnoKc

[@vladimiriliev9877]

Can this 7 segment display be connected to PLC and if so how?

[@robojax]

Here I have shown how to use it with microcontroller such as Arduino kzbin.info/www/bejne/eIGnk4hqpaeGrNU this video is part of my Arduino Step by Step course

[@twistedyogert]

Thinking about building a calculator, how do I do a multiple didget display using a decoder chip?

[@robojax]

For calcualator better option would be LCD1602 kzbin.info/www/bejne/p2q8dJJ9i62sa6M or LCD2004 but you can do it with LED display TM1637 kzbin.info/www/bejne/fGbVmaF8jZiSrZo and you will need a keypad kzbin.info/www/bejne/p3qnq619Z7GIqsk or this kzbin.info/www/bejne/mmXFpGt3bc6AgJI

[@johngordd5612]

thank you, was very helpful.

[@Tnapvrvideo]

Can these LEDs be controlled by a potentiometer to display voltage allowed to pass through the "Pot" and into the circuit?

[@robojax]

so you want them to be voltmeter? Not by itself but if you use an IC or Arduino, then you can send number to display. Here is how to use seven segment display with Arduino: kzbin.info/www/bejne/nGSqooWDhp2dj9U

[@velut480]

great vedio @robojax i have a doubt how to show the temp and humidity value in the 5 digit 7segment display. 3 digit for temp and 2 for humidity can u help me plz thanks in advance

[@robojax]

You are welcome. You will need some kind of driver or chip or arduino. This is your best Option is TM1637 using Arduino which I have a video on it: kzbin.info/www/bejne/eqbEnp2iqNmCga8 and here all my videos that I used this TM1637 chip with 4 digit display kzbin.infosearch?query=TM1637

[@hiralalpawar5924]

How to show 2 separate digit on 2digit display working

[@robojax]

Here is the counter and you can make two of it kzbin.info/www/bejne/nGSqooWDhp2dj9U or use this 2 digit module: kzbin.info/www/bejne/oV7JZ5-trLqHd9U

[@arturorivera6871]

this is a very clear explaination but I need more from two digits because my has 18 pins.

[@robojax]

How many digits it has? would you please send the text or model written on it?.

[@arturorivera6871]

HXO4231BBW-02

[@robojax]

I searched it online and got zero result. Where did you buy it. Send me a link of the store.

[@zer0b0t]

I have one of those too, mine is common anode so there are two leads on the top where you connect the positive, they are next to each other I think it's pin 13 and 14

[@pcnikos7836]

thank you very much for your help and one question how much volts do i need with green because mine it doesnt work with 2.40 volts

[@robojax]

2.4V is already maximum. put a resister in series and revers the polarity. you might have connected it in reverse.

[@pcnikos7836]

@@robojax thank you for your help and your quick answer i will try it and i will answer.

[@pcnikos7836]

It works it was my first time that i use 7-segment display thank you for your help

[@yogeshitaliya473]

Please teach some cnc coding Thankyou

[@JoeCnNd]

I want to make a 5v 10k pot where the 2 digit 7 segment LED tells the voltage that's being resisted by the pot. Do you know of any good tuts on this? I'll be using a LM317 as well.

[@robojax]

Do you want to make voltmeter to show the AC/DC voltage?

[@clarkso65]

Thanks your a blessing!

[@robojax]

You are welcome. I am pleased you found it useful.

[@johnspain2037]

Following your explanation I am wondering how you display a two-digit number where oner and tener differ from each other on the 7-segment display with two digits. So numbers not like 22, 55, but like 27 or 64? Do you use a clock and switch between the digits with a speed where the eye is not able to notice the on and off of the digits?

[@robojax]

It requires separate tutorial which I have plan to do but not sure when as I am busy with school doing my master's degree and a full time job.

[@johnspain2037]

@@robojax thanks for the reply. I just need something like a hint at the moment, no detailed tutorial or long technical answer. And your answer seems to show that you know how its done and what the concept is. Am I wrong with the second part of my initial comment (switching very fast between the two digits) or is it done another way (all just in terms of basic approach/concept, as I said)? Thank you!

[@robojax]

that is called multiplexing and yes that is exactly how it is done and you are right.

[@waqarmehdi4394]

thank u very much sir truly it was helpful for a beginner like me..................... thank u very much...................

[@robojax]

you are welcome. I am glad you found it useful.

[@taranagnew436]

do the 7 segment displays have to be hooked up to ground?

[@robojax]

at 01:15 I have mentioned that we have either command Anode which will be connected to + or VCC and then each pint for the a, b,c,d,e,f,g will be connected to - or Ground or GND. If we have common Cathode, then the Cathode will be ONE pin and it will be connected to Ground or GND. But the each anode of pins a, b, c,d,e,f,g will be connected to +.

[@سهيلابرهيم]

تشكر على هذا المجهود

[@robojax]

عقوا

[@ThreeDeeIcon]

Very Nice... Subscribed

[@robojax]

Thank you very much. Thank you for not skipping the ads and keep watching them. This will help me a lot.

[@williama-d6]

How do you make it count down with out the Arduino?

[@robojax]

without Arduino, you will need a lot of ICs to do it. You can do it with PIC16F84 chip or 89C2051 chip.

[@williama-d6]

@@robojax thanks I just say a video with a chip tutorial have you got a schematic that you can send me with it?

[@robojax]

I don't have any schematic. You can search it google or Bing and you will find.

[@ssnoc]

can't hear you - don't you realize that?????

[@robojax]

I just checked it, the sound level is not loud but you can hear. Just increase the volume. I will see if I can increase the volume of audio in the clip.

[@engrsharifkakar]

Nice video keep it up

[@robojax]

Thanks.

[@Adiledit2.0]

Very bad tech experience

[@robojax]

Thank you.

[@VackerSimon]

Thank you! This helped a lot

[@robojax]

you are welcome.

[@techworld3498]

Good information

[@robojax]

Thank you.

[@arduinotech1374]

yAR CODE TO NAHI HA

[@robojax]

नमस्ते, यह वीडियो 7-सेगमेंट डिस्प्ले का उपयोग कैसे करता है नहीं कोड या arduino यह एक सामान्य परिचय है मैं इस डिस्प्ले का उपयोग करते हुए एक और वीडियो पोस्ट करूंगा। धन्यवाद।

[@lantechbd]

Thanks

[@robojax]

You are welcome.

[@Underwaterbob]

Forgive my newbiness, but is there no way to display two separate digits simultaneously on the 2-channel display? The segments on each digit share an anode, so I can't see a way you could pass current through one and not the other unless you alternated quickly or something which seems really inconvenient.

[@robojax]

@Jason Gould, Yes you . we have separate cathodes. see the page from data sheet snag.gy/h7NQ1Y.jpg you can turn on each digit sepearately

[@Underwaterbob]

Thank you! Mihail Stefanov Multiplexing is something I'm aware of in computer monitors, but didn't know was done on such a small scale as this. What I get from this is if you were to make a 0-99 counter with a couple of 4026, you would not want to use this particular display because you'd need something between the 4026s and the display to get it to display properly.

[@Underwaterbob]

Robojax This is not the device in the video though, no? This one has 18 pins and would operate as though it were two separate single digit, 7 segment displays next to each other.