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Topic: Increase the number of PWM outputs? (Read 931 times) previous topic - next topic

elimenohpee

Hi, is there an easy way to increase the number of pwm outputs available on the duemilanove?  It has 6 built into the chip, but I wanted to be able to drive more than 6 outputs.  I thought about using some kind of serial-to-parallel shift register, but I've never tried pulse-width modulating with those chips, and wasn't should how to accomplish that since you are only sending in bits (how would the outputs know to pwm??).  I also thought about writing code utilizing the interrupts, but I don't have tons of experience coding.  Any help would be great!  Thanks so much!

CaptainObvious

You could use Shift Registers like you suggested. PWM is basically just turning on and off at different rates.. you can emulate it with any pin, just takes away from other valuable time.

Shift Registers is a good idea.. there is a library some where around here that allows you to use the 595's as a PWM output. You could also just get Analog chips, such as the 4051 I believe. I've never used the 4051 personally but there are ALOT of examples.
http://www.arduino.cc/playground/Learning/4051

Grumpy_Mike

Quote
You could also just get Analog chips, such as the 4051 I believe


No you can't. This is an analogue multiplexer and is nothing to do with PWM.

streety

This looks promising: http://www.arduino.cc/playground/Learning/TLC5940

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