Alt-BEAM Archive
Message #09070
To: beam@sgiblab.sgi.com beam@sgiblab.sgi.com
From: Dennison Bertram dibst11+@pitt.edu
Date: Wednesday, 12 January 2000 3:00
Subject: RE: BEAM VIDEO was RE: Solar Powered Camera's
>Oh yee of little faith! We have to start small to start anything! Just
think
>of the actual possiblites and ramifications! Imagine the doorways that
would
>be opened if we worked out a method by which to decode video signals so
that
>we could interface them with Nu circuits! Imagine directing your next
walker
>with a tiny video camera the size of a Capacitor, the possibilities become
>wide open. Sure you could do it better with LDR's at this point, but the
>point isn't to just tell where the best light source, we want to be able to
>design systems whoes future purposes could be complex pattern regonition,
>and object tracking. It's hardly stupid, it would be a serious start, and
>would warrent it's own entire field of BEAM applications. Evolution baby,
>yeah!
>
>
>dennison
>
>
>wow! But with only four quadrants it seems stupid considering the same
thing
>could be accomplished with 4 LDR's. It would need more complexity to be
>worth while. How hard would it be to say track an object? Or differentiate
>between simple shapes. Would the 8x8 be enough?
>
>Very promising though!
>
>David
>-----Original Message-----
>From: Wilf Rigter
>To: 'beam@sgiblab.sgi.com'
>Date: Wednesday, 12 January 2000 1:13
>Subject: BEAM VIDEO was RE: Solar Powered Camera's
>
>
>>BEAM circuits are very similar to the older analog type video technology
>>still used in simple B/W TVs and 20 years ago all televisions used analog
>>beamlike circuits for decoding video signal.
>>
>>So it's not surprising that it is fairly simple to use BEAM circuit blocks
>>to convert video into digital or analog signal suitable for interfacing
>with
>>other beam circuits. In the example suggested by Dennison below, The video
>>signal is converted into a 2x2 matrix which corresponds to the average
>>light level of a quadrant of a video frame. The attached block diagram
>shows
>>the general concept of such BEAM video decoder.
>>
>>A composite video signal (ie a sugar cube camera output) is processed by a
>>sync separator to produce Horizontal and Vertical sync pulses as well as a
>>DC restored video signal. This circuit requires some 2N3904s and a few
>>passive components. The H and V sync signals each trigger a Hsync Nv and
>>Vsync Nv (74HC14) respectively which are adjusted to time out at a point
>>corresponding to the horizontal and vertical midpoint of the screen. The
>>signals are connected to one half of a 74HC139 (Z bridge) which generates
4
>>control signals corresponding to each screen quadrant. These 4 Q signals
>are
>>used with four 4066 analog gates to route the video signal to one of 4 Nu
>>(74HC14). The analog voltage on each Nu cap corresponds to the average
>video
>>signal of that quadrant This can be used to "influence" a central pattern
>>generator like a microcore. A digital signal can be generated with a one
>bit
>>A/D converter also know as a comparator or Schmitt trigger. If the video
>>level on the Nu cap is above the trigger level of the comparator, a LED
>>turns on. A bright light moving from one quadrant to the next, will turn
on
>>the corresponding LEDs indicating the relative position of the light.
>>
>>This concept can be scaled up to a low resolution "gray scale" (or red
>>scale) monitor (ie 8 by 8 LED matrix) which can also be easily made with a
>V
>>and H chains of 8Nvs each buffered with HC240 LED drivers which can drive
>>64 LEDs in real time. The video signal is "sliced" by a comparator the
>>output of which drives the HC240 tristate enable lines. No Nu stages are
>>needed to measure the average video since your eyes will do a visual
>>integration of the LED light level. Any old video signals can be used for
>>experimenting with this concept including a camcorder or VCR video output.
>>
>>regards
>>
>>wilf
>>
>> <> <>
>>
>>
>>> -----Original Message-----
>>> From: Dennison Bertram [SMTP:dibst11+@pitt.edu]
>>> Sent: Tuesday, January 11, 2000 10:07 AM
>>> To: beam@sgiblab.sgi.com
>>> Subject: Solar Powered Camera's
>>>
>>> Hey, look at:
>>>
>>> http://www.mpja.com/allpict.asp?dept=125
>>>
>>> You should see the "sugar Cube" Camera. It runs on 5v 10ma, a power
level
>>> easilly provided by a solarcell. Any ideas? Possibly, Hey Wilf! think
you
>>> could come up with something to interpret video signals? What would be
>>> MOST
>>> interesting is if we could find away to interpret the general LIGHT
level
>>> of
>>> a quadrant of the cameras vision. IE LEFT, RIGHT, UP, DOWN. That way we
>>> could then use cameras as light level inputs to say, a head. I'm
thinking
>>> that analog wise, this might be a little difficult.
>>>
>>> dennison
>>
>
>
Home