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how to increase i/o pins in arduino Answered

i am working with an ethernet shield project. i need more i/o pins for my project.  My need may increase upto 1000s too.

using one ethernet shield connected to a single arduino board has only 14 io pins. using MUX will not be use ful for my project.

Please help me with solution for this.


4 Replies

The Skinnerz (author)2012-07-01

Depending on the requirements of the outputs, using shift registers could work, especially when used with a multiplexer, although data rates would be very low compared to regular I/O pins.

Have a look at some of the larger or more complex LED cubes, as they manage to apply PWM to hundreds of individual LEDs from a microcontroller.

What are you trying to connect to that would require that many I/O pins?

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ananth raj (author)The Skinnerz2012-07-02

i am connecting home appliances with it.

So each applicance has to be controlled individually and some times in group.

while controlling individually MUX couldnt be a better one. so i need many I/O pins which has to control every individual appliances seperately.

Is it possible to connect single Ethernet Shiled with many Arduino Boards. so that i can get many I/O pins?

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iceng (author)2012-07-01

Your no engineer,  consider the current load on a circuit if that many
i/o are active.

Look at distributed uP applications as a first exercise for something
better then Brute force...


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steveastrouk (author)2012-07-01

Look at chips like Maxim's MAX7301 I/O expander - very versatile, easy to use, and cascadable.

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