Re: poor man's IO?

[shb*NO*SPAM*@comporium.net (Si Ballenger)]

On Fri, 29 Jul 2005 15:32:31 GMT, Marc F Hult
<MFHult@xxxxxxxxxxxxxxxxxxxxx> wrote:


>>>The least expensive RS-232 solution (not USB) I know of uses the 74LV8153
>>>which is in stock at www.Digikey.com  for $1.58 each. This is a single IC
>>>solution for RS-232--> 8-Bit discrete output using one IC and a few
>passive
>>>components.
>>>
>>>Writeup and schematic here:
>>>www.elecdesign.com/Articles/ArticleID/10524/10524.html
>>
>>I got some of these chips a good while back from TI, but wasn't
>>successful in getting them to work. I'll try the schematic wiring
>>and the exe program to see if I can get them going now. Using
>>some cheap 74hct259 latching chips, one should be able to get
>>~120 individually controllable output lines per 74LV8153 chip.
>
>When I first saw the article (in hard copy), I was struck by the fact that
>it was needed at because it is possibly the simplest application.  It's need
>comes from the fact that the TI application doc is at best sparse with
>explanation.. The article I referenced is a bit better and makes clearer the
>design implications of the IC's low-input-voltage application and shows a
>handy way to provide two different Vcc's.

The demo exe program is vey helpful for understanding the byte
protocol used by the chip. The fact that it will operate at the
lower 4800bps means it might be able to be connected to the very
inexpensive RF chips for wireless control. Also should make for
easy and inexpensive web controlled applications.