MATRIX DISPLAY

archu vijay said:

d i would like to design a 8x8 matrix display...

As Luis & I have past discussed - far easier to build/assemble - and vastly more efficient (and capable) display media exist.  For example - a 1.5" OLED featuring a 128x128 pixel matrix - pin saving SPI input - is sub 15 (USD) @ Q1. 

128x128 enables your display of (likely) multiple words in any language - 8x8 does not.

Text only displays bought me a house on the ocean - yet Apple/others have taught that "real graphics" add much excitement & real value.  And 8x8 proves enormously restrictive - so limits you!  Expansion adds labor, size, cost - note that you rarely see such displays other than in commercial, advertising applications.  (far less applications/volume use - than a "proper" graphic module!)

Should you not find the suggested OLED there exist multiple small graphic LCDs: 122x32, 128x64 are likely (lower cost) suspects...  As a small firm employer - we'd be more impressed by one w/real graphic programming/manipulation skills - rather than one demo'ing a, "hodge-podge" of wires to a (pardon) bit enfeebled 8x8 (even 5 of them) pixel matrix...  Our, "Pick n Place & 20' long reflow oven" build hardware - we expect our hires to write disciplined, imaginative SW - not "cobble" wires!

You may wish to "kill" the flying (opening/abandoned) "d" - the insertion of an (occasional) upper case char is more normal/customary...

hi Luis Afonso

thnk for repl..

I made a project using the Tiva to control allot of TLC5940, https://sites.google.com/site/luiselectronicprojects/rgb-matrix/tlc5940. There's a zip attached for download in that page.

i had gone through the link but i am not able to download the file. where the other link is working and trying to implement it.

i want to implement the display in a matrix form.please give any suggestion regarding this.

Hi archu,

Like cb1 said, for that size your better off with a some kind of LCD or other screen.

Just look here https://www.youtube.com/watch?v=WoU_PZIL4zg . A bit hard to read don't you think? even if it's for a hobby toy. Maybe if it's longer like 8x24 it should kinda work.

There are also plenty led displays in the market for that purpose.

Anyway, if you want to go through i will try to upload the code later if i find it.

And cb1, you don't imagine what i learnt for making that project, well it's not made, just the software. So it wasn't anything lost that's for sure. So many people asked me to teach them now how to use the Tiva that i have a small class in my club, which means more funding for my projects.

Luis Afonso said:

And cb1, you don't imagine what i learnt for making that project

Oh Luis - but I do!  Years/decades past - before the introduction of the basic LCD Character Module - my early firm built 1x16, dot matrix, LED modules by stringing together four, 1x4 HP Led matrix modules.  And then we had to find, buy & program an MCU prior to the ready introduction of C compilers for small MCUs.  There's very much similar between your task & my past...

As I said - so much of the large matrix poster now describes is NOT SW - it is mechanical assembly.  Thus - his learning is "held hostage" by the poor decision to employ a "tool" (8x8 matrix Led) not well suited to, "task!"  (creation of a usable display)

How much more would you - and poster learn - freed from simple (yet brain killing) mechanical wiring issues?

Instead you'd be able to fully & properly focus upon: "Bitblts, screen contention, and effective pixel-image commands & manipulations.  Indeed you learned much - but you may have learned even more - and become more employable - via that same effort - but more commercially directed. 

I don't write to be mean/unkind - but to provide a "signpost" when I sense poster's have improperly chosen.  Not all will welcome - far easier for me to do/say nothing - yet many here value these guides - and much good results...

1 note to archu, to control a LED matrix you should use a line by column, like this http://img.alibaba.com/img/pb/635/364/624/624364635_917.jpg 

cb1,

I definitely agree that for the size proposed of 8x8, it's without a doubt better a LCD screen.

Do note something cb1, i never programmed without arduino based IDEs before like Energia. Something like a LCD would be just a bit overwhelming at the time. Also, i didn't have access to any kind of screen nor the money for it so it wasn't viable. I do have my eyes on a LCD from the TI workshop (overpriced if you ask me) to start learning how to use one. 

Something to note, i could give to a newbie the most complex task, if it was to hard he would not learn 1 thing. He would probably learn more if i asked him to blink a simple LED by the press of the button.

Would i learn more from using a LCD? Most likely. It involves much more and is more useful, i wish i knew how to use one. But overall i'm happy with it. Remember i am 2-3 years earlier learning all this so let's take it slow, i still have classes to pass

Luis Afonso said:

Remember i am 2-3 years earlier learning all this so let's take it slow,

My initial writing here was not directly to you - it addressed original poster - and follow-on/interested others.

I stand by the following:

a) poster's desire to create "words" in multiple languages - is miscast via 8x8 led matrix.  (even several leds, edge-butted)

b) all interconnect wiring time/effort subtracts from that available for "real" graphic screen experimentation

c) displaying a single pixel upon a parallel input, small graphic Lcd is not that much harder than doing similar upon a home-made/wired 8x8 Led matrix.  To meet your requirement - that pixel may also be ordered to, "blink."

d) understand I don't write (always) for the individual - but for many - who may benefit from my past tech business experience & reasonable time/effort here.  (and other places)  So while (you) urge, "take it slow" - I believe it's better to make "good decisions" - ones which have more chance at commercial success & properly guard posters' time/effort/funds. 

e) when all said/done - cost of (multiple) 8x8 matrix Leds & driver ICs & assembly time/labor/debug most likely approximate that of 122x32 lcd or (earlier mentioned) 128x128 OLED.  Clearly lcd/oled is superior - provides a vastly larger "canvas" - finds use in most any "serious" electronic product (unlike 8x8 matrix) and is of far more interest/value to prospective employers and/or project managers...

Our perspectives are very different - I'm targeting a broad user base - not any "one individual" in particular. You may wish to think more globally (and then (likely) will naturally proceed faster due to superior, "up-front" course survey/selection...