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Topic: Multiplexing & PWM (Read 1 time) previous topic - next topic

SiskinFinch

Currently I am working on a project that will use an Arduino Pro Mini and needs to control 18 LED's independently with PWM. The Arduino can only do 6 independently...so what part would I need to buy to expand the number of outputs? I know shift registers can only do on/off functions, not fading, so that's not it...

Whatever help I can get would be awesome!

MarkT

How high a PWM frequency?  PWM can be done in software too...
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John_Smith

you could use 3  TPIC6B595 shift reg/latches for up to 24 LEDs and pwm them with their notG ( blanking ) pin.

only needs 4 pins of the Arduino chip.
45 years of editing projects with a knife and soldering iron, then I found Arduino !

dc42

Check out the ShiftPWM library, or use a TLC5940.
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Hippynerd


Check out the ShiftPWM library, or use a TLC5940.

Im just learning about this stuff, and from what I've read, this seems to be the way most folks are doing things. TLC5940 seems to be limited to common anode, but it seems to be the most elegant way.
https://sites.google.com/site/rgbledcubes

Grumpy_Mike

The term common anode and common cathode only make sense when dealing with multicolour LEDs which for the OP he is not doing.

There are many chips that give PWM control over LEDs. The TLC5940 will only drive 16 LEDs however the TLC5947 can controll 24.

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