Arduino 56x8 scrolling LED matrix
Powerlines
56 resistors
After several tries, I was able to fit seven 8x8 matrix side-by-side on a breadboard and not have wires crossing over the displays. The key is to put the chips on one side (rather than above or below) the matrices. You can put another 7 driver chips on the right side and double this to a fourteen 8x8 side-by-side matrix!!!
By customizing the breadboard, I was able to rearrange where the power buses are and use them not for power, but to have a common bus for the eight anode rows shared by all displays.
Code is available in the Arduino Forum. See the eleventh message of this thread.
16 comments:
Ok Hari, now you just need to make the display just a little big bigger and create a BIG SCREEN TV! ha ha ha
GREAT JOB HARI!
Tony
Hi! I am trying to make the same project. Can you help me please with the code? I want to scroll the letters and I have no idea how to do that!
Thanks
e-mail: voina_cristian@yahoo.com
Halo Hari, bagus sekali hasil karyanya. Bolehkah saya melihat skema nya? Saya ingin coba tapi bingung dengan skema nya. Terima kasih sebelumnya.
What is the model number of the LED matrix modules that you used? Were they a perfect fit in the breadboard?
Daniel,
Yes, they are a perfect fit for the board. I got mine on ebay. Unfortunately, I can't remember the seller's name. If you search for led matrix red, you will find them. Mine has this printed on it LD788BS-GT10.
sir am very sad tpic6c595 is not available in india what can i do as a replacement for that ic can i use 74hc595 insted of it
I'm not sure if you can use the 74hc595 for both rows and columns because I believe the tpic allows the pin to be floating whereas the 74hc595 will bring the pin high or low. Current capacity is another concern.
However, I'm unfamiliar with a replacement. Sorry...
Hi Hari,
Firstly, your scrolling LED is cool and fun...
I built a one 8x8 LED Matrix with a common cathode with 2 x 74595 ( columns is anode and rows is cathode to sink the current... )
I took yr codes posted from Arduino Forum and modify it to suit for my common cathode rows LED Matrix.
The screen is scrolling fine but those the alphabet could not be seen except for the 1st column is full brightness but the next 4 columns is dim ( some suppose to be OFF )
Only for char H, I can see two full brightness vertical bar but the horizontal bar is missing...
I tried to speed up or slowdown the scrolling speed but still the same effect. Those LED that suppose be off is lid but very dim.
Is this because the refresh rate is not fast enough ?
You are not using multiplexing to scroll the text, right ?
Thank you
Stanley
@stan001, I suspect that maybe because you're using two 74595. I wonder if because those pins are never floating so the elements interfered with each other?
You are correct, I am not using multiplexing to scroll the characters, all that is done in the array.
Good luck!
hooh...
nice project.
I relay like the size of protoboard
u assambled it on.
BYE
Can I get your permission to use a modified version of your code for my arduino to Silent Radio LED sign conversion project? Thanks! It is at bobdavis321.blogspot.com
@BobDavis, certainly, have fun with the code! Cool projects on your blog!
Nice work dude...Really want to try this...
Hello !
What a great job :)
Please, have you more photo or picture to help me for my electronical connection ?
Why did you say that we need one 10K resistor ?
Thanks a lot :)
@themykie, thanks. The 10K is to set the clear pin to high. Without it, the shift register would be continually be in clear mode and none of the bits would ever get set. Sorry I do not have anymore photos. :-( They probably won't help anyway because it is very easy to get lost in the dense jungle of wires. :-)
Thanks Hari for your answer :)
I have an other question...
Why do you use two different shift register, and not only the 74hc595 ?
Cause I can't find the TPIC6C595, and is very expansive with the export :(
Do you know an other component ? Or can I use just the 74hc ?
Thanks a lot :)
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