Step 3: Schematics

The only thing I didn't specified in the schematics is the value of the current limiting resistors because they change from each type of LEDs, so you will need to calculate them by your self.

Now to calculate the value of the 24 resistors you can use this site : 
You should first get some specs on your LEDs, you should know their forward voltage and forward current, you can get this info from the seller. The circuit operates on 5V so your Source voltage is 5V.

Download the original file to see the schematics better.(press the "i" icon in the top left corner of the picture)

I have added a PCB layout of the control board, and i want to thanks Willard2.0 who made this layout and let me use it so thanks a lot mate!


<p>I want to make 64x6 screen.... so I guess I'll be needing 8 shift resistors, but for that do I i have to use 8 pins of the arduino uno?</p>
Figured tat out... still 3pins is required... how stupid of me to even ask tat question<br>
I want to make it.but I don't know about code this. Please help me my email is 15146158@hcmute.edu.vn
<p>L&agrave;m thế n&agrave;o để biến đổi th&agrave;nh bảng mattrix 24x8 ạ..{ chủ yếu l&agrave; code}, em vẫn l&agrave; d&acirc;n nghiệp dư mới tập t&agrave;nh n&ecirc;n xin h&atilde;y gi&uacute;p đỡ em ạ<br>địa chỉ email của em đ&acirc;y ạ: cantho1995ct@gmail.com</p>
<p>Could you send me some photos, of your shift registers, the decade counter, and your Arduino hookup, I will be glad to see if I can help you. My email is akhilash4877@gmail.com</p>
<p>Thanks Akhil, I sent you an e-mail.</p>
<p>My LEDs doesn't have brightness enough, anyone could help, I made a 11x10 matrix using the same project and components.</p>
<p>Try lowering the value of the current limiting resistors you used on the columns. He used 24, I am assuming you used 11, but lowering the value should give you more current through the LEDs and make them brighter.</p>
<p>I will try, thanks for helping =)</p>
<p>LED have two pin,</p><p>which led pin are connected to row,</p><p>and which led pin are connected to column,</p><p>please help...</p>
<p>Generally the longer pin is the Anode(+), the shorter pin is the Cathode(-). So the longer pin should go to the column, the shorter to the row. In case you hadn't already gotten an answer for that. </p>
<p>So I am looking at embedding this into a small system with custom PCBs and running it from a battery. Would anyone be able to tell me what current draw they have? I need to figure out how many mAh's I need my battery to have. Thank you.</p>
<p>excuse me. if this running text expanded to 48x6 with just adding more register is possible?</p><p>and the matrix module is needed a zener to secure led from broken?</p><p>thanks</p>
<p>I have a code that has been modified to recognize the additional shift registers for the 48 x 6 display and would be happy to share it with you, if you contact me at my email address; gplyr8@gmail.com. Also I have not found the need for the zenerk, but you will need to add some small capacitance capacitors to your ground on the shift registers, to avoid trouble. I also have an updated schematic for the display.</p>
<p>I know this is a bit old but do you still have the code for a 48 x 6 display? I'm hoping to adapt it to a 32 x 8 display that I've made. My email is: Sharon97Q@gmail.com. Thank you kindly.</p>
<p>Hi could you send me this code please - martinhinks@btinternet.com - Thank you.</p>
<p>No problem. I sent it to you.</p>
<p>thanks for the information and instruction. it's helpful. now i'm will develop it to 48x6 running text.</p><p>maybe i'm need to exploring the variation of the animating movement of text,hehe</p>
<p>actually, I'm still onworking progress on board. i made the PCB based from 24x6 with additional expansion for 24 lines. </p><p>does it will be ok?</p><p>oh, plus, the board that i will use is arduino nano. is it capable enough for the display?</p>
<p>Not sure about nano, but it should be able to handle it.</p>
hai Syst3mX, how to modify 24x6 to 128x6, if you can help me to modify the source code??<br>let me know via email: nurhadiahmad88@gmail.com, thanks and success for you
<p>Hi, did you get any code? </p>
<p>Just made this - works perfect but tried to use a 6x32 system but the last 8 digits shadow the first 8 :( - I guess its the code, does anyone know how to change this code so it can be customised for any system. Thank you.</p>
<p>have you had any trouble with the 74hc595 chips burning up? or is the manufacturer data on the low side in the max amps trough the chip.</p>
<p>hello, this is a cool project im making one on my breadboard for testing before i fix it to a pcb. i will just ask why do we need those transistors? i'm a beginner btw. thanks for your reply :)</p>
<p>The transistors amplify the output voltage from the decade counter, and also acts like a switch, when there is no current at the base, there is little to no current flowing from the collector and the emitter. Without them all you will get is a column of six LED's scrolling across the matrix, no defined characters. You can find all kinds of information on how transistors work. </p>
and by the way, is there, by any chance, a way in which I can only use a shift register? I don't know how to use the decade counter using an arduino. I mean, I know how to use it using a pwm pin but its not the same way you can control an output from a shift register.
You could use six pins on your arduino or add in a shift register and have it be on pins 1-6 on the output, then just use the first six digits of the byte to control each transistor. If I understand everything correctly.
great! thanks ?
<p>There might be a way, but you will still be using a PWM pin for the output, to control the shift register. As the code being used controls the Arduino.</p>
<p>hello, thanks for the tutorial, I have run the code and not turn anything, should I change something in the code to turn on a led? and I checked piece by piece the electronics and everything is fine.</p><p>Greetings.</p>
<p>Hi, I have built Syst3mX's project and his code works fine as is for a 24x6 matrix. I am willing to help you if I can. If you would like my help private message me.</p>
Please someone help me out to complete this.
Please send the code for 24*6 matrix that you have explained above. I want to make it
Can I have code for 48*8 matrix thanks in advance
Is it possible to expand the amount the amount of letters or numbers that i can scroll across the 24x6. I would like to scroll my address for the mailbox. mrebarnas82@gmail.com if anyone has any ideas
<p>GREEN LED</p>
<p>How do I use the serial monitor to display typed text?</p>
<p>What type of LEDs did you use?</p>
<p>not work properly later like <a href="http://www.instructables.com/member/Miggyparas15" rel="nofollow">Miggyparas15</a>made it! please give me schematic and code</p>
<p>What would need to change in the code if a 24x10 Matrix was constructed instead of 24x6? </p>
<p>All of these variables below need to be changed to 10. </p><p>[6] r&lt;6 p&lt;6 y&lt;6 i == 6 h&lt;6 k&lt;6</p>
<p>Could the same code be used if I were to add an additional 16 columns to the 24? I would add an additional 2 595 shift registers and cascade the date from the first to the next allowing 40 total outputs or 40 total LED anode columns. I would imagine something in the FOR loop would need to change. Any comments would be great! :)</p><p>-Sky</p>
<p>I am afraid his code is limited to 24 columns, however I have been able to modify, his code to work with more shift registers. Send an email to gplyr8@gmail.com</p>
<p>hey I made it 24 x 8! but I seem to have encountered some problems.. only columns of led show up with no visible movements or animations. Do you know what might have caused this problem? I tested all my leds after soldering, all works fine. btw, I'm using the loop code. and great instructable though.</p>
<p>Could you send me some photos, of your shift registers, the decade counter, and your Arduino hookup, I will be glad to see if I can help you. My email is gplyr8@gmail.com</p>
<p>I'm using an arduino UNO and forgive my circuitry skills..I'm still new to this. could it be the decade counter or shift register fried up? </p>
<p>Hello guys, Can anybody explains me the code ?</p>

About This Instructable




Bio: Electronics and LEDs what can be better ?! :D
More by Syst3mX:Make a Desktop Tamagotchi LED Binary Calculator Make a 24X6 LED matrix 
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