Got this project working with 8 modules. Mind you they came as 2x4 joined up and they had to be separated (fret saw), turned through 90 degrees and rewired. Cheap enough at 5 ish euros from eBay. I now have a scrolling "Merry Christmas" and I'm very grateful for the tutorial. I'm going to see if I can get it working with a keyboard input. But that might be beyond my programming skills so if anyone else manages it, please publish. Ho Hum and a very Merry Christmas to everyone.
When we did this tutorial we were using the 1.0.5 version of the Arduino IDE. It seems that if you're using a newer version of the IDE Software you need to replace ‘prog_uchar’ with ‘const unsigned char’ in the tutorial sketch to not get an error when compiling.
Thanks for pointing that out Sygaro! Posted a comment to notify people of this fact on our website at brainy-bits.com/tutorials/scroll-text-using-the-max7219-led-dot-matrix/
I like your projects ,Yvan, and have successfully built the Nokia 5110 display and sonar range finder a couple of days ago and the 8x8 scrolling text today which worked straight away after replacing ‘prog_uchar’ with ‘const unsigned char’ in the tutorial sketch. I started with 2 and then tried 8 units which worked. If I wanted 16 units would I need an Arduino Mega which has more memory? Next I would like to type in new messages with the serial port. Maybe Serial read and press send. Followed by an NRF24 tx/rx setup.
+binarybox Let me check because I'm not sure if the library supports more than 8 modules? But if it does support more than 8, you wouldn't need a MEGA since the modules are linked together and would not use more pins on your UNO. Haven't played around with the NRF24 so couldn't help you with that, but if you do please let me know how it went. Thanks for watching btw :)
+Brainy-Bits Could you please let me know that do we need external power source somewhere if we try to run 8 such matrix together for scrolling message? I worry if 8 matrix would take more power from Arduino nano and Arduino would burn?
Each one of the LED Matrix consume approx. 70mA at peak, so 8 of them would be around 8 x 70mA = 560mA. Or around 0.56Amps at 5V. So you would need a separate 5V power supply when using 3 or more of them since the Arduino can Source no more than 200mA on the VCC pin. Thanks for your comment and watching!
Hii, I tried to connect 8 such dot matrix display together and run your code after changing it appropriately for 8 dot matrix display, I am using Uno. I am now supplying external power to the 8 daisy chained dot matrix displays as suggested by you before. I am finding that after running for some time, the characters in the matrix getting corrupted. This is happening in say one or two matrix displays and not all. Sometimes it happens in some or other matrix while other matrix displays perfect out of 8 matrix. When I reset the Uno then it start running the text perfectly for few minutes (4 to 5 minute) and then again the corrupted text appears in some or other matrix. Could you please let me know what could be the problem? Do we need to put some capacitors to the matrix displays? I will now trying to reset the UNO using reset function by putting reset function in the sketch itself somewhere so that my program could reset the UNO after certain period of time automatically while it displays the text. Lets see how it works..
Hola un saludo desde Colombia. Gracias por tan buen tutorial, Tenia problemas para hacer funcionar este modulo pero con su ayuda lo logre y es fatastico. Tengo una pregunta: como hago para conectar mas matriz MAX7219 y ampliar los mensajes. Gracias
+carlos carlosama La biblioteca se utilizó en este tutorial fue un poco escamosa, voy a tratar de hacer un nuevo video pronto con una técnica diferente, a fin de mantener un puesto de observación para que uno en el futuro. ¡Gracias por mirar!
I tried to connect 8 units of 8x8 dot matrix display, after i change the program for 8 units and try to display alphabets in scrolling mode then after few seconds the text gets corrupted.. I dont know why this is happening... While its works good if i use four or five units or less units together.. Please help.. Thank you.
Help; I use IDE version 1.6.12 and i have understand that i must change the code in line 3 of the sketch,This line have this text in my sketch: #include , so, i will change it but i can't follow this suggestion: "Change prog_uchar to const char" ?? I don't find these characters!
+John Ang Thanks for watching! The library worked well enough for some things, but I think the developer just stopped updating it and there was some unfinished functions and some bugs left in it. I would still like to thank the person who created it and congratulate him or her for their work :)
I bought a 4 matrix array that are mounted next to each other but the problem is that the writing is going vertical and not horizontal.. any way to quickly rotate the text 90 degrees to the right? Thanks.
Hi there, I'm trying to connect the 8x8 displays to an ultrasonic sensor. is there a way to have the displays show the output as static, updating text rather than scrolling?
You are doing it wrong. Don't use pin 10 for clock, use pin 13. Use header file and let that clock out out the bits. Don't use shiftOut(), when you dont have to.
Hola,como puedo hacer para que me salgan ordenadas las letras en cada matriz sale lo mismo,e seguido los tutoriales y no consigo cambiar lo que quiero,gracias
+Pedro Pacheco La biblioteca se utilizó en este tutorial fue un poco escamosa, voy a tratar de hacer un nuevo video pronto con una técnica diferente, a fin de mantener un puesto de observación para que uno en el futuro. ¡Gracias por mirar!
Just upped the number of matrices to 12 and although the scroll happens the data is random pixels. Reduced the number to 9 and all is well with the remaining 3 matrices just repeating the first 3, which is expected behaviour. The code seems to dislike anything above 9, that is double digits in that variable. Has anyone else noticed this? Help! I need this fixed before Christmas.
Hi Alan, I made this tutorial quite a while ago so had to refresh my memory, the library used is limited and from what I can tell it has a limitation of 9 matrix. So for now I don't have a solution to use more unless we use a different library. Will try to make another tutorial using a different library soon, but unfortunatly it will be after the holidays. Sorry about that, but thank you for your comments and for watching of course. Have a merry Christmas and Happy New Year...
Is it possible to use 18 or more horizontally? Also can this setup be controlled by a computer running software to display RSS feeds? I want to make a massive news ticker for my living room from this setup. Any help would be appreciated.
+hydrolisk1792 The library we used in this tutorial was a little flaky, I will try to make a new video soon using a different technique, so keep a lookout for that one in the future. Thanks for watching!
+Sourav Mahanty The library we used in this tutorial was a little flaky, I will try to make a new video soon using a different technique, so keep a lookout for that one in the future. Thanks for watching!
Thanks again for watching! You can find the code and more information on all our tutorials on our website: brainy-bits.com/tutorials As for the current needed for 8 LED Matrix, since each one would consume approx. 70mA at peak, then 8 of them would be 8 x 70mA = 560mA. Or around 0.56Amps at 5V. So you would need a separate 5V power supply when using 3 or more of them since the Arduino can Source no more than 200mA on the VCC pin.
The library we used : MaxMatrix, should be able to do this, but after testing, it seems that it doesn't work the way it should. We are looking into ways to fix and update the library, and will reply here with results. Thank you for watching!
any idea why I'm getting this? c:\users\me\appdata\local\arduino15\packages\arduino\tools\avr-gcc\4.9.2-atmel3.5.3-arduino2\avr\include\stdio.h:677:12: error: expected ')' before 'char'
Hi, this tutorial was made a while back so with the new version of Arduino IDE (1.6 or newer) you have to change prog_uchar to const char in the code (third line). Hope that helps :) thanks for watching.
Hey guys, I know that the code is flaky - But I can't use 10 or more matrizes. If I use 9, it works like a charm, but as soon as I use 10 or more, I only get random pixels flashing without any real text. Any way to fix this? Thanks in Advance
+Andres Avendaño Not sure, since the code used in this tutorial is drawing each letter or character in a different way than CodeGraphics outputs. The code draws the characters using 5 columns wide. I don't think that CodeGraphics can draw this way. Thanks for watching!
Thanks for watching! Well the library we used only includes Ascii printable characters from 32 to 127, so it doesn't include the characters you want, which are in the extended range of 128 to 255. You would need to create those characters yourself and modify the library to include those. You can see the Ascii table here: www.ascii-code.com/
+Sourav Mahanty The library we used in this tutorial was a little flaky, I will try to make a new video soon using a different technique, so keep a lookout for that one in the future. Thanks for watching!
Got this project working with 8 modules. Mind you they came as 2x4 joined up and they had to be separated (fret saw), turned through 90 degrees and rewired. Cheap enough at 5 ish euros from eBay. I now have a scrolling "Merry Christmas" and I'm very grateful for the tutorial. I'm going to see if I can get it working with a keyboard input. But that might be beyond my programming skills so if anyone else manages it, please publish. Ho Hum and a very Merry Christmas to everyone.
When we did this tutorial we were using the 1.0.5 version of the Arduino IDE. It seems that if you're using a newer version of the IDE Software you need to replace ‘prog_uchar’ with ‘const unsigned char’ in the tutorial sketch to not get an error when compiling.
gracias amigo por decir la solución
sorry but i can"t find this " ‘prog_uchar’, there is nothing like this in your code.
Thanks a lot for an easy and simple tutorial for the beginner!!! Keep up the good work.
Thanks for the video. You saved me alot of time working on my project and having to buying new matrix displays.
Sorry for the delay :), great to hear the video helped! Thanks for watching.
Thanks. the code is really easy to understand.
It seems that we can do much more if we just modify the code a little. Great tutorial.
Glad it helped you. Thanks again for your comment and for watching!
Awesome stuff- thanks for sharing :) looks like one of the LED's is out- the fifth one up on the left hand side of the second matrix module.
Nice catch! :) Never noticed that... Thanks for watching so carefully btw :)
If you use IDE 1.6 or newer you have to change the third line of the code. Change prog_uchar to const char
Thanks for pointing that out Sygaro! Posted a comment to notify people of this fact on our website at brainy-bits.com/tutorials/scroll-text-using-the-max7219-led-dot-matrix/
How can I adjust code to rotate LED MAX7219 matrix text 90 or 270°
I like your projects ,Yvan, and have successfully built the Nokia 5110 display and sonar range finder a couple of days ago and the 8x8 scrolling text today which worked straight away after replacing ‘prog_uchar’ with ‘const unsigned char’ in the tutorial sketch. I started with 2 and then tried 8 units which worked. If I wanted 16 units would I need an Arduino Mega which has more memory?
Next I would like to type in new messages with the serial port. Maybe Serial read and press send. Followed by an NRF24 tx/rx setup.
+binarybox Let me check because I'm not sure if the library supports more than 8 modules? But if it does support more than 8, you wouldn't need a MEGA since the modules are linked together and would not use more pins on your UNO. Haven't played around with the NRF24 so couldn't help you with that, but if you do please let me know how it went. Thanks for watching btw :)
+Brainy-Bits Could you please let me know that do we need external power source somewhere if we try to run 8 such matrix together for scrolling message? I worry if 8 matrix would take more power from Arduino nano and Arduino would burn?
Each one of the LED Matrix consume approx. 70mA at peak, so 8 of them would be around 8 x 70mA = 560mA. Or around 0.56Amps at 5V. So you would need a separate 5V power supply when using 3 or more of them since the Arduino can Source no more than 200mA on the VCC pin. Thanks for your comment and watching!
Hii, I tried to connect 8 such dot matrix display together and run your code after changing it appropriately for 8 dot matrix display, I am using Uno. I am now supplying external power to the 8 daisy chained dot matrix displays as suggested by you before. I am finding that after running for some time, the characters in the matrix getting corrupted. This is happening in say one or two matrix displays and not all. Sometimes it happens in some or other matrix while other matrix displays perfect out of 8 matrix. When I reset the Uno then it start running the text perfectly for few minutes (4 to 5 minute) and then again the corrupted text appears in some or other matrix. Could you please let me know what could be the problem? Do we need to put some capacitors to the matrix displays?
I will now trying to reset the UNO using reset function by putting reset function in the sketch itself somewhere so that my program could reset the UNO after certain period of time automatically while it displays the text. Lets see how it works..
Hola un saludo desde Colombia. Gracias por tan buen tutorial, Tenia problemas para hacer funcionar este modulo pero con su ayuda lo logre y es fatastico. Tengo una pregunta: como hago para conectar mas matriz MAX7219 y ampliar los mensajes. Gracias
+carlos carlosama
La biblioteca se utilizó en este tutorial fue un poco escamosa, voy a tratar de hacer un nuevo video pronto con una técnica diferente, a fin de mantener un puesto de observación para que uno en el futuro. ¡Gracias por mirar!
I tried to connect 8 units of 8x8 dot matrix display, after i change the program for 8 units and try to display alphabets in scrolling mode then after few seconds the text gets corrupted.. I dont know why this is happening... While its works good if i use four or five units or less units together.. Please help.. Thank you.
Help; I use IDE version 1.6.12 and i have understand that i must change the code in line 3 of the sketch,This line have this text in my sketch: #include , so, i will change it but i can't follow this suggestion: "Change prog_uchar to const char" ?? I don't find these characters!
looking forward to the new library to replace the flaky one.
+John Ang Thanks for watching! The library worked well enough for some things, but I think the developer just stopped updating it and there was some unfinished functions and some bugs left in it. I would still like to thank the person who created it and congratulate him or her for their work :)
+Brainy-Bits thanks, looking forward to the new video with the new technique.
I bought a 4 matrix array that are mounted next to each other but the problem is that the writing is going vertical and not horizontal.. any way to quickly rotate the text 90 degrees to the right? Thanks.
Ever figure this out? I'm having the same problem
works fantastic.
thanks a lot.
keep up the good work.
god bless you.
Great to hear it helped! Thanks for watching!
Hi..I have problem in coding scrolling led display... Can u help me
Sir code is working good for me.
i want to add hc-05 ?? how can i update code?
Hi there, I'm trying to connect the 8x8 displays to an ultrasonic sensor. is there a way to have the displays show the output as static, updating text rather than scrolling?
can this library be used to display non scrolling text? I want to display a left aligned message and an incrementing counter across four matrices.
You are doing it wrong. Don't use pin 10 for clock, use pin 13. Use header file and let that clock out out the bits. Don't use shiftOut(), when you dont have to.
amazing stuff.. thank you for sharing!
Hola,como puedo hacer para que me salgan ordenadas las letras en cada matriz sale lo mismo,e seguido los tutoriales y no consigo cambiar lo que quiero,gracias
+Pedro Pacheco
La biblioteca se utilizó en este tutorial fue un poco escamosa, voy a tratar de hacer un nuevo video pronto con una técnica diferente, a fin de mantener un puesto de observación para que uno en el futuro. ¡Gracias por mirar!
On which software we should apply this code
Just upped the number of matrices to 12 and although the scroll happens the data is random pixels. Reduced the number to 9 and all is well with the remaining 3 matrices just repeating the first 3, which is expected behaviour. The code seems to dislike anything above 9, that is double digits in that variable. Has anyone else noticed this? Help! I need this fixed before Christmas.
Hi Alan, I made this tutorial quite a while ago so had to refresh my memory, the library used is limited and from what I can tell it has a limitation of 9 matrix. So for now I don't have a solution to use more unless we use a different library. Will try to make another tutorial using a different library soon, but unfortunatly it will be after the holidays. Sorry about that, but thank you for your comments and for watching of course. Have a merry Christmas and Happy New Year...
Is it possible to use 18 or more horizontally? Also can this setup be controlled by a computer running software to display RSS feeds? I want to make a massive news ticker for my living room from this setup. Any help would be appreciated.
+hydrolisk1792 The library we used in this tutorial was a little flaky, I will try to make a new video soon using a different technique, so keep a lookout for that one in the future. Thanks for watching!
Okay Cheers and good luck.
I don't know what i am doing wrong. The LED matrix is just displaying random pixels! HELP!!!
+Sourav Mahanty The library we used in this tutorial was a little flaky, I will try to make a new video soon using a different technique, so keep a lookout for that one in the future. Thanks for watching!
+Brainy-Bits any chance you could do it on a pro mini or a micro??? if they are compatable
how to use with one matrix?
Hey u used an arduino uno
Can u share the code what u used
And i wanted to ask if u are using 8 together
How much voltage needed ??
Thanks again for watching! You can find the code and more information on all our tutorials on our website: brainy-bits.com/tutorials
As for the current needed for 8 LED Matrix, since each one would consume approx. 70mA at peak, then 8 of them would be 8 x 70mA = 560mA. Or around 0.56Amps at 5V. So you would need a separate 5V power supply when using 3 or more of them since the Arduino can Source no more than 200mA on the VCC pin.
Any ideas on how to invert the entire animation ??
Like i want the chips to be on top and the matrix below it
Please help
The library we used : MaxMatrix, should be able to do this, but after testing, it seems that it doesn't work the way it should. We are looking into ways to fix and update the library, and will reply here with results. Thank you for watching!
any idea why I'm getting this? c:\users\me\appdata\local\arduino15\packages\arduino\tools\avr-gcc\4.9.2-atmel3.5.3-arduino2\avr\include\stdio.h:677:12: error: expected ')' before 'char'
Hi, this tutorial was made a while back so with the new version of Arduino IDE (1.6 or newer) you have to change prog_uchar to const char in the code (third line). Hope that helps :) thanks for watching.
Hello dear, I don't arrive to download the library to the link you gave, I don't find the button clone or download
try this link here: github.com/riyas-org/max7219 you should see the download button on the left side. Hope that helps and thank you for watching!
how can I make my own letter?
Hey guys,
I know that the code is flaky - But I can't use 10 or more matrizes. If I use 9, it works like a charm, but as soon as I use 10 or more, I only get random pixels flashing without any real text.
Any way to fix this?
Thanks in Advance
Hi, I gave exactly the same problem, the code doesn't like maxInUse to be greater than 9. I'm still looking but did you manage to fix it?
Unfortunately not :( I gave up at some point and just used 9 matrices. Sorry. If you find some way to do it, let me know.
how can i use the code when i have 3 led matrix using a max7219
+joeri van driessche probably in the area where you define how many matrix you have.
Hi,Can I use CodeGraphics in this code?
+Andres Avendaño Not sure, since the code used in this tutorial is drawing each letter or character in a different way than CodeGraphics outputs. The code draws the characters using 5 columns wide. I don't think that CodeGraphics can draw this way. Thanks for watching!
HELP, it says " letter_scroll_2:5: error: 'prog_uchar' does not name a type" help!
+MANRACLE GAMING If you use IDE 1.6 or newer you have to change the third line of the code. Change 'prog_uchar' to 'const char'
thanx :)
It's Always about Arduino with libraries...
Thanks for good tutorial! How can I add letters Ä ä Ö ö Å å?
Thanks for watching! Well the library we used only includes Ascii printable characters from 32 to 127, so it doesn't include the characters you want, which are in the extended range of 128 to 255. You would need to create those characters yourself and modify the library to include those. You can see the Ascii table here: www.ascii-code.com/
where is the code!!
plz.. send me , this code
it shows "bra" in the thumbnail
Can you change the text string while the program is running? I am trying to make a bluetooth controlled one.
+Sourav Mahanty The library we used in this tutorial was a little flaky, I will try to make a new video soon using a different technique, so keep a lookout for that one in the future. Thanks for watching!
send me this code