Building a 5x16 led matrix?

Hey guys, just warning you that I'm a noob in Arduino (Don't even have one of my own), but a great avatar pictures picker.

So... here's the deal:
I have this project on where I want to make a 5x16 (five leds in series per 16 parallel columns) led matrix. But, as I don't think I can get a 74HC595, I'm thinking if there's a way of increase the Arduino Operating Voltage? In this case I could arrange the leds in series and control them column by column using the Arduino. The big problem is, the Arduino only give us 5V, so the maximum number Leds I could put on series would be just 2, reducing so much what I was planning.

So, in resume, those are my troubles:
Can I increase the tension that Arduino can operate?
Would be harmful for the Arduino to arrange 16 parallels columns of Leds and put each one in a digital port?

Some data:
The leds are 10mm red (=~2v).
I only have Arduinos Uno's availables.
The voltage I'm going for is either 12v or 9v, that would be enough for the Matrix.
I'm a noob in eletronics as much as I am in Arduino, but I'm a good learner :smiley:
You can't be happy until you have aleatory 3 nipples
English is not my native language, please correct my mistakes.

five leds in series per 16 parallel columns

All 5 are to turn on together? Or you want them all individually addressable?

Yes, together.
Individually would be great, but I guess I would have to buy more stuff and eletronics are not that easy to get where I live (buying from the internet may slow my time)

So what do you have for current drivers and current sinks?
74HC595 is a crappy part without buffering. Can you get TPIC6B595?

I only have the Arduino, the Leds, some cables and resistors. That's all about what I can easy get here.
TPIC6B595 and similarities are quite hard to find, and I don't know where to search those in my city, so I think that I can't get any shift register but the ordinary ones (If I get lucky).
That's why I'm searching for a way to increase the Arduino operating voltage, so I can make the circuit with not too much more than the board, leds, etc...

You need transistors. What city?

Even if you could get the 74HC595, you would still need something that is capable of handling the current all those leds draw. Neither the arduino nor the 74HC595 can do that. You'll at least need some transistors as suggested. And with multiplexing it would be possible to make each led work individually. (alas if you use an uno you would be 1 pin short of making it without a shift register like the 74HC595, you would need 5 pins for the rows and 16 pins for the columns for multiplexing it (there are arrangements that need less pins, but that makes it more complex)).

Your main issue now as said by the others is finding some transistors so you can make something that can draw the required current.

TioMOG:
So... here's the deal:
I have this project on where I want to make a 5x16 (five leds in series per 16 parallel columns) led matrix. But, as I don't think I can get a 74HC595, I'm thinking if there's a way of increase the Arduino Operating Voltage? In this case I could arrange the leds in series and control them column by column using the Arduino. The big problem is, the Arduino only give us 5V, so the maximum number Leds I could put on series would be just 2, reducing so much what I was planning.

You can charlieplex them in groups of 5 pins. Each group of five pins lets you control 20 LEDs:

fungus:

TioMOG:
So... here's the deal:
I have this project on where I want to make a 5x16 (five leds in series per 16 parallel columns) led matrix. But, as I don't think I can get a 74HC595, I'm thinking if there's a way of increase the Arduino Operating Voltage? In this case I could arrange the leds in series and control them column by column using the Arduino. The big problem is, the Arduino only give us 5V, so the maximum number Leds I could put on series would be just 2, reducing so much what I was planning.

You can charlieplex them in groups of 5 pins. Each group of five pins lets you control 20 LEDs:

Controlling 20 Led's From 5 Arduino Pins Using Charlieplexing : 8 Steps - Instructables

I guess Charlieplex will not be pratical, since my led matrix must be arranjed in a perfect rectangle, and I'm putting individual control as second plan.

racemaniac:
Your main issue now as said by the others is finding some transistors so you can make something that can draw the required current.

CrossRoads:
You need transistors. What city?

I'm from Brazil, living in Fortaleza.
The town have a bunch of eletronics stores, but in this project I can't use too much or spend more money than I should.
About the transistors:
What kind and where I'll put them in the matrix?

Another question: If I reduce the matrix to 2x16, I could use the Arduino operating voltage and manipulate the leds by column without harming the shield? I do not intend to light them all at the same time, just column by column. It would use only 2 leds per time.

How about 4x16?
2 LED string, 2 strings per IO pin. Current limited to avoid IO pin damage.

CrossRoads:
How about 4x16?
2 LED string, 2 strings per IO pin. Current limited to avoid IO pin damage.

You basically solved my problem.
Just a few questions:
This scheme is complete or is there anything else to increase to the circuit?
200 ohms per resistor or 2 resistors of 100 ohms per string?
There's a specific material to do the welding or any metal string is pratical?

TioMOG:
About the transistors:
What kind and where I'll put them in the matrix?

Just about any general purpose NPN transistor will be fine, as most are rated to at least 30V and 100 mA.

If you use transistors as buffers, you can use 12V to feed LEDs in strings of five (with resistors of course), or up to at least 3 parallel strings per transistor. You need a series resistor in the base connection to each transistor (about 2k2 would generally be fine).

resistor and 2 LED/string, 2 strings on each IO pin.

I didn't see any answer to your first question.

No, you cannot increase the voltage that the Arduino operates at.

CrossRoads:
resistor and 2 LED/string, 2 strings on each IO pin.

I think part of you message is missing...

michinyon:
I didn't see any answer to your first question.

No, you cannot increase the voltage that the Arduino operates at.

This case was for me to use the complete 5x16 matrix without switchers, etc.
But thanks, anyway :smiley:

That's the design. How you connect it all up is up to you.
You haven't said what you have for assembling all the parts, if it needs to final/permanent, or just a temporary assembly, or what ...

CrossRoads:
That's the design. How you connect it all up is up to you.
You haven't said what you have for assembling all the parts, if it needs to final/permanent, or just a temporary assembly, or what ...

It's permanent.

Then find some "island of holes" perfboard, start soldering components in place, and start wiring.
See "experimenters board" and "PCB board" here as examples
http://www.futurlec.com/Protoboards.shtml#PRBRDLG

CrossRoads:
Then find some "island of holes" perfboard, start soldering components in place, and start wiring.
See "experimenters board" and "PCB board" here as examples
http://www.futurlec.com/Protoboards.shtml#PRBRDLG

Thanks, man.
I'm going tomorrow search for the components and start to make the circuit
Thanks for all the help, man :smiley:

Glad to help.