Keyboard De-bounce &
Decode using a Parallax
BASIC STAMP 1.  
Remote control
via RS-232
    I use the MSComm control of
VB6.0 to synchronize Audio Precision
Measurements to/with multi channel
output devices.

1 of 4 Inputs  to: a 4-way Break Out

Each of the 4 inputs is selectable:  Optical, (TosLink) / Coaxial, (transformer coupled).

Each of the 2 outputs consists of: 1 Optical and 1 Coaxial plus a signal present LED.

Normal Configuration is: 1 of 4 inputs to a 4-way break out.

Can be configured as: a 1 of 3 inputs to a 2-way break out,  with an external loop.  (To allow inserting an external
processor into the current signal path.)
    Under program control this switch allowed me to make FASTTEST measurements on 4 different S/PDIF pairs of a multi channel signal processor, 8 channels,  in 47 seconds.

    The signal source being bit streams stored on the HD of a second PC and played back under control of the main test program on a Primary PC.  The remote control of the bit
stream source PC is by TCP/IP.

    The secondary PC maintains a list of available bit streams and only requires the filename of the desired bit stream.  The secondary PC finds the bit stream, loads the
appropriate playback code and plays the bit stream.

    On a busy TCP/IP network, the turn around time from play request on the Primary PC to bit stream present at the AP digital meters is about 140ms.
This is a 6 channel speaker switch with
remote control by RS-232.
3 pairs of two speakers
L/R, C/Sw, Sl/Sr
Push Buttons :
Front
Center / Sub Woffer
Surrounds.
Mute.
Button de-bounce and decode with
Parallax Basic Stamp 1.  The Stamp
provides RS-232 and switch condition
memory on EEPROM.
This is a 4 X 4 analog cross point switch.
Side view shows CD-4066 Quad Bilateral
Switches.  They are controlled by
CD-4013 D-type F/Fs.  Uses 4 NiCad AA
cells to provide switch condition memory.
4 X 4 Analog Cross Point Switch.
Top View.

Each input has a voltage follower feeding a +/-20dB gain stage.  

The switching is done with summing nodes fed by the 4066s.  

Two split supplies plus NiCad charger.

Key de-bounce with CD4584 Hex Schmitt.

ULN2804 as LED driver.

Power transformer is Stancor SW-828 Split Bobbin.
This is a Multi Channel A/B switch.

Selects 1 of 2 stereo inputs to 2 stereo
outputs.

Selects 1 of 2 six channel inputs.

Sends to a 6 channel output.

Hardwire remote.

Each stage has +/-20dB of gain.

The bottom level contains two +/- 0v to
+/-16v DC and 0 to 16v adjustable
regulated outputs.  These supplies are
for powering a D.U.T.
Page Background Image:
This is a switch condition display for an 8 X 8 stereo
crosspoint switch.  It consists of 64 Red/Green LEDs.
Providing Red, Green and Orange color indications.  Can be
used as an X/Y index or 8 channels level display.
     I originally made this switch so I would have an absolute and easy way to disconnect from the Internet.

     Four relays are used to carry the network signal and one is used as a power latch for the others.  Powered from the PC, the switch always opens when the PC is powered off,  but will
not come on until the power button is pressed.  The On/Off push buttons are next to my keyboard.

     I have no base band modem in my system, so the only way out to the Internet is via the ADSL.

     I was having a test of will,  with a worm virus that I call the
"3721.Com" virus

    It got in through a tool bar installed by my ISP.  It recorded and reported key strokes.  It was set up in the registry to only attempt running once per boot when IE sets up.  Other than that
it basically stayed very quiet.  The only hint of it's presence was Chinese  characters appearing in the tool tip text of the IE address bar.

     What made it difficult to get rid of was that it kept several copies of it's self,  I think in the registry, in RAM and on disk.  It constantly checked the locations of the files and if they were
removed it rewrote them.

    At that time,  about all I could do was to prevent IE from getting to the Internet at boot and kill a file called "mshp.dll" that contained the recorded key strokes to be reported to 3721.  I
wrote a program that when saving an image as background will make a serialized copy of the image file.  I had it keep an eye out for "mshp.dll" and let me know when present, so I could
personally kill it.  After some research I figured out how to use the Recovery Console to prevent it from protecting itself and was able to delete all it's component files, about 4 to 6 files in all.

    Now my primary use is when down loading my email.   I log into any other folder than my In Box when the mail is down loading.  When finished,  I disconnect from the Internet before I
preview my new mail.  That way hidden image files contained in Spam can not ping the originating site.   It also comes in handy to stop Pop-Ups dead in their tracks.

    Draconian,  yes,  but you can't write around an open relay.

    When I was in high school a few friends of mine and I had a 3-way phone system on our block.  It stretched about 0.1 miles through the trees in front of our houses as well as through
the back yards of other houses.  We used steel guide wire to carry the cooper in the trees on the street.  This was in part due to the need of some of our other school mates to want to pull
our wires down.  One afternoon one of my friends noticed a kid climbing a tree headed for our wires.  He disconnected the wires from his phone and when the kid had a good hold,  plugged
our phone wires into the wall socket.  It didn't hurt our phones,
did knock the kid out of the tree.  Nobody complained, nobody's parents at the door, no more problems with our wires.  
Done deal !
  I just found out the other day when
searching Goggle on "ET-142" and
"NBC", that Dolby loaned one to NBC to
take to China for the Olympics.
Audio Bit Stream Switch.
Intended for 32k to 48k Hz S/PDIF & AES/EBU bit streams.
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