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Topic: Led Garment (Read 1 time) previous topic - next topic

zerokite

Hi guys

Im currently working on a project for uni

to make a led shirt

I'm thinking of using 100+ LEDs, and be able to create patterns or texts with the leds (maybe with switch? so i can change it around)

I'm not sure what arduino is suitable for this kind of project, and I only have a little experience with arduino programming.

Please give me some advice guys~~~

Any help greatly appriciated!  ^_^

Thanks Very much!

CrossRoads

#1
Sep 06, 2012, 07:35 pm Last Edit: Sep 06, 2012, 07:38 pm by CrossRoads Reason: 1
100+ LEDs is more IO than any arduino can handle directly.
What might be more straight forward is to use an Uno and have it control two MAX7219 or MAX7221, www.maxim-ic.com,  matrix driver chips.
Each can handle 64 LEDs. Your control is to write data into registers. Each register represents 8 LEDs.

Otherwise, a string of shift registers that control 8 LEDs each (one LED per output) such as this, which controls 96 LEDs, could be another way to go.
Same idea - you write bytes of data to a shift register, with an LED per output pin. This board uses TPIC6B595, for high voltage/high current (>5V and 20mA) operation, intended for 12V LED strings. If you only need single LEDs from 5V, than 74HC595 will work just fine.

Other chips are also possible, such as TLC5940 from ti.com, 16 PWM'able outputs,
or WS2803, world semi, with 18 PWM'able outputs. Only source I've seen for wWS2803 is e-bay, guy in Niagara Falls selling them.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

zerokite


CrossRoads

Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

zerokite

is it possible to do this project without the shift register? (maybe with least leds)

CrossRoads

Sure - limit it to 20 LEDs, the max number of IO on an Uno.
D0-D13 amd D14-D19 (the A0-A5 pins).
Each LED needs a current limit resistor.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

zerokite

i see~  thanks for the tip


CrossRoads

Well, that uses a couple of extra chips.
If you could cut back to 8x8 you could do that with just a single MAX7219, a resistor, and 2 caps.
The MAX7219 is available for $1.25 from www.taydaelectronics.com, Thailand
Or use two for 128 LEDs, 8 x 16 or however you'd like to arrange them.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

zerokite

ok, 128 sounds good

zerokite

Does it mean if i have 4 max7219 chips I am able to control 256 leds? (just want to make sure everything is right)

CrossRoads

4 x 64 = 256. Yes, that math seems to be correct.
I am working up a similar project for a scrolling text display; four MAX7219, four 8x8 matrix, bare minimum arduino design to control it. Parts ordered, waiting on delivery.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

zerokite

i have got 4 max7129 and everything, expect for the perfboard in this project : http://www.instructables.com/id/810-LED-Matrix-with-4017/?ALLSTEPS

and for the resistor..i wasnt 100% sure
so i end up getting all 150,160, and 180ohm

I need help with the circuit.. like how to connect these components.. (e.g Schematic)

zerokite

only have vero board

cjdelphi

For that many...

A decent sized battery (to power all this with)
ShiftRegisters (eg, 500 led's would be 500/8  = 62 shift registers)
What Power source to do all this? (eg, if each LED was 20ma, are all your LED's going to be on at once?... or off... eg, 500 leds * 20ma @ 5v?)
Transistors to switch all this current on (as Arduino can ony supply 40ma per pin, and 120ma? for all... So, include Resistors)...

Anyway this is quite a big build..

Esp when you have to take into consideration all the resistance from the AG Line thread / conductive thread you're buying, due to the resistance you
could cut down on costs as the resistor could be part of how long your thread is...

There's many way's to go about it though.....

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