Hello,
are your biosensors returning graded (analogic) signals or state changes (eg. 0
to 5 volts);
if the former you will need to uses an analogue to digital converter and read
each sensor
sequentially:
using the serial port for output:
i) select the sensor you want to read using a multiplexor
ii) reset the AD convertor and then read its input value from the sensor;
then
using the serial port for input:
i) read the value of the analogue convertor (maybe more than one byte if
the AD converter is more than 8bit);
then repeat for all other sensors;
You might be able to find a serial port analogue data logger circuit project
which you could adapt;
You will probably need amplification for the imput if the sensors are really
microvolt! (millivolts are more likely)
If you are also using the port for stimulation, obviously you will need to
control output (I presume that this is also analogic) which will also need to
be selected via a multiplexer and the desired voltage probably generated by a
digital to analogue converter;
Since the circuit is to be attached to a human being, it might be a good idea
to have optical isolators on the serial port (to block high voltages from the
computer discharging into the skin sensors!). The output skin stimulation could
be from batteries carried on the circuit board.
Let me know if this is useful.
See also:
http://www.babanibooks.com/
Easy PC Interfacing
PC Interfacing with USB
Kevin
----- Original Message -----
From: "Robert Meek" <[EMAIL PROTECTED]>
To: "'Borland's Delphi Discussion List'" <[email protected]>
Sent: Sunday, July 23, 2006 3:43 PM
Subject: RE: Serial Port and USB I/O...some additional OT questions in thisarea
> I was taking a look at Asynch from TurboPower...now Open
> Source...and it seems that it wouldn't be difficult at all to handle simple
> asynchronous instructions via a serial port or even USB w/serial adapter.
> My question has more to do with hardware than anything else.
> What I'm attempting to do is write my own program for handling very
> simple bio-feedback data. What this entails are one to x number of
> lightweight micro-volt sensors which are affixed by adhesives to various
> points on the body, ( usually the forehead, mandible, or temples, and in
> some cases fingers and/or wrists ). A battery operated computer board which
> I'm building from supplies readily available at Radio Shack, measures the
> changes in resistance between two or more of these paired contact sensors
> and emits a signal which I then wish in turn to read and show via visual and
> auditory feedback. This will be accomplished via a retentive scope-type
> display that plots a graph, a single point visual which moves up, down,
> left, and right, in its response to the same signals, as well as a user-set,
> continuous sound that travels up and down the scale in relation to the
> signal. The data will also be saved and stored as a stream in a local
> database for re-play and analysis.
> Secondary to its uses for personal bio-feedback will be the ability
> to provide variant wake level cues via sending micro-shocks back thru the
> sensors to the person's skin at pre-programmed and AI-controlled intervals,
> ( in response to dynamically measured sensor data ), for lucid dreaming
> experimentation, and pain control.
> Not being an electronics wizard myself, ( the most complicated
> electronic device I ever built was a specialized light-meter for measuring
> grey values as used in the Zone system during darkroom work on b/w
> photographic negatives ), I have a friend working out the hardware design
> for me. Unfortunately, he is has unknowledgeable about computers as I am in
> electronic control and measurement systems and so I need to find out the
> signal characteristics this hardware can submit via the serial port, as well
> as what it can expect in return!
> So I was hoping someone who has some experience with these areas
> might be able to contact me off-list and give me a few pointers in this area
> so that I can then in turn ensure the hardware handles the necessary
> signals. If so please contact me at the e-mail address below:
>
> [EMAIL PROTECTED]
>
> from Robert Meek dba Tangentals Design CCopyright 2006
> Proud to be a moderator of "The Delphi Lists" at elists.org
>
> "When I examine myself and my methods of thought, I come to the conclusion
> that the gift of Fantasy has meant more to me then my talent for absorbing
> positive knowledge!"
> Albert Einstein
>
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf
> Of Mick Arundell
> Sent: Saturday, July 22, 2006 8:35 PM
> To: [email protected]
> Subject: Re: Serial Port and USB I/O
>
> Serial ports are/can be treated as files
> WriteLn(PortName, 'here, read this');
>
> Mick
>
> > Date: Fri, 21 Jul 2006 15:48:43 -0400
> > From: "Rainer von Saleski" <[EMAIL PROTECTED]>
> > Subject: Serial Port and USB I/O
> > To: "Borland's Delphi Discussion List" <[email protected]>
> > Message-ID: <[EMAIL PROTECTED]>
> > Content-Type: text/plain; charset="Windows-1252"
> >
> > This is going to sound awfully stupid ... but I've searched the
> > Delphi help to no avail.
> >
> > How do I do I/O to/from a serial port? And/or to a USB device?
> >
> > I understand interrupt handlers, used them in Borland Pascal, so
> > they must be present somewhere. But I can't find them!
> >
> > Where do I look? Someone please get me started!
> >
> > Thanks,
> > Rainer
> >
> >
> > ------------------------------
>
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