Hi AAC,

Heard a few people at work talking the other day of an idea that I would like to know thoughts on!

It is an IO breakout board for when IO numbers become a problem.

It uses a max 5 IOs that can give 16 IOs....an extra 11.

It works by 1 IO being the master and the other 4 are used in a counter scenario that choose the output on the breakout board.

E.G....... 1 0 0 0 1 from the Arduino would choose IO number 1 on the breakout board. Up to 1 1 1 1 1 that would choose IO 15.

Obviously an MCU, protection blah blah needs adding, just looking out for feedback. Also I am unaware if this is already available .

Cheers,
JSwale

 

74LS154 4-Line to 16-Line Decoder/Demultiplexer

General Description Each of these 4-line-to-16-line decoders utilizes TTL circuitry to decode four binary-coded inputs into one of sixteen mutually exclusive outputs when both the strobe inputs, G1 and G2, are LOW. The demultiplexing function is performed by using the 4 input lines to address the output line, passing data from one of the strobe inputs with the other strobe input LOW. When either strobe input is HIGH, all outputs are HIGH. These demultiplexers are ideally suited for implementing high-performance memory decoders. All inputs are buffered and input clamping diodes are provided to minimize transmission-line effects and thereby simplify system design.

Also the 4051 is a SINGLE 8-CH ANALOG MULTIPLEXER DIP-16

 

There are plenty of multiplexer shields,etc.. for both platforms..
https://www.sparkfun.com/products/11723

 

We used a few MUX chips at work with an arduino mega, the goal was to reduce the number of wires in the wiring harness that wrapped around our machine. On paper it all looks dandy, but in the real world when the IO starts flying around it didn't always work well and was a PITA to debug. It was a few years ago and I don't remember the details, I just remember wishing the IO's were all connected directly to the arduino.