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General Category => General Discussion => Topic started by: etaphi on December 12, 2010, 10:38:19 AM

Title: Simple RS232 Encoder/decoder help
Post by: etaphi on December 12, 2010, 10:38:19 AM
Hi there,

Sorry - I'm new to this forum but there are some excellent threads and information here - so thank you so far already.

I'm an electrician by trade, so electronics are not my speciality so a little help here would be great.

I would like to create a small PCB that will allow me to send multiple switches down few wires than I would generally use.  To explain this better, imagine if I had 15 switches to send to a remote location, but I didn't want to have to use a 30 core cable, is it possible and cost effective to create a small PCB that could encode this information on a single pair of cables and then decode it at the other end using serial communications or is there something even easier?

(furthermore the signal would be 5V digital - on/off)

Thanks for you help
Title: Re: Simple RS232 Encoder/decoder help
Post by: kam on December 12, 2010, 19:08:21 PM
that will be very easy to design. you need a PISO (Parallel in - Serial Out) encoder to encode 8 (or 16 or 24 or 32...) channels, and then a SIPO (serial in parallel out) decoder. 3 wires are enough for the transition. No need of microcontroller or such.

PISO: 74148 (can be any 74148 such as 74LS148 or 74AS148 or 74HC148, i suggest 74LS148)
SIPO: 74164 (also any type-suggest LS)