Re: USB module for monitoring multiple on/off switches

[J Miller <reply@here>]

Josepi wrote:
> RS-485 is a two wire serial port that can support multi-drop peripherals.
> Translator adapters RS232/RS485 can be purchased for about $25.
>
>
> "Christopher Glaeser" <nospam@xxxxxxxxxx> wrote in message
> news:fo2dnYYWE7lUR33XnZ2dnUVZ_oGdnZ2d@xxxxxxxxxxxxxxx
>>> Why USB?  It can be done almost directly with a serial ...
>> Directly, as in one port?  I need to monitor multiple alarms and need
>> multiple ports, as in 8 or more.
>>
>> Best,
>> Christopher
>>
>>
>
>
Actually, I was talking about simply using a pin on the port.  For a
serial port, you got two pins, and for a parallel, you got 8-10, IIRC.
Using direct IO.  You read the port and see the logic state if the pins...

No buss involved..

Another option is a Dallas ds2490 (?) USB to one wire adapter buss
(~$25).  Then, with ds2401's or DS2405's (~$2 each)  you can sense a
bunch of spots, but the SW to do so is more complex.  I've had my best
luck with the Linux version of the Dallas SW than the windows version...