Re: Help th idiot with simple 1-wire setup ...

[J Miller <reply@here>]

Marc_F_Hult wrote:
> On Sat, 7 Mar 2009 21:52:02 -0800 (PST), dogfuel <joseph.b.baird@xxxxxxxxx>
> wrote in message
> <a000af2c-d3d0-4cb1-b7c6-04834a9bc564@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>:
>
>> If I need to monitor two normally-open switches and log when and how
>> long they are closed, I can do this with a DS9490R USB bridge and a
>> D22 Channel Digital I/O 1-Wire Card ... correct???
>>
>> The software to monitor is no problem for me but I am new to data
>> acquisition and monitoring.
>>
>> Thanks in advance!!!
>
> What is a "D22 Channel Digital I/O 1-Wire Card" ?
>
> Yes, a 1-wire DS9490R will connect a USB port on a computer to a 1-wire
> integrated circuit such as a DS2450 that could be used to sense contact
> closure.
>
> Depending on your application, you may find the 1-wire system to be neither
> very robust nor inexpensive compared to a $5 (shipping to US included ) USB
> to 25-pin parallel printer cable/converter.
>
> Search eBay for: usb parallel
>
> Visit: http://www.lvr.com/parport.htm
>
>
> HTH ... Marc
> Marc_F_Hult
> www.ECOntrol.org

Even if you go with 1-wire (BTW, I like Marc's Idea), a couple of
DS2401's would do it..  They are 1-Wire "ID" devices, and based on the
switch are on or off buss, the switch state is known.  In a TO-92, they
could be right on the switch and just require the net and GND.

I use this set up in a few areas of the house, but I also have other
sensors on the buss (temp) and DS2405's to have LEDs display things!

Another option if there is a free serial port is to use DSR and CTS (or
DTR and RTS, depending on your perspective!) to be the state of the two
switches