Blast or Confirm this theory..

Oldbitcollector (Jeff)

Been mulling a communications theory around for the last year,
posted here to either blast or confirm, (or possibly point out that
it has already been designed)

Preface.. Computers communication via 1's and 0's (on/off)
The speed of the communication being how fast we can toggle them,
as well as how many 1's and 0's we can send at a time. (bus width)

What if ADC's were used to communicate voltage ranges
instead of 1's and 0's? We could "say" more with fewer
physical connections. 10% voltage is one thing, 20% another.

Is this type of communication in use already? Nutty idea?
or OBC has seen into the future?

OBC

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
New to the Propeller?

Getting started with the Protoboard? - Propeller Cookbook 1.4
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card? - PropDOS
Need a part? Got spare electronics? - The Electronics Exchange

MarkS

It's plausible, but it doesn't take much to get a 10% swing in an analog line. This would be prone to data corruption without suitable (and heavy) shielding.

MSDTech

It's called an Analog computer. These were developed for some very special applications (usually simulations).

Mike Green

It's been done. There have been some experimental computers built with ternary logic that can have 3 states, 0, 1, or 2 represented by 3 voltage levels. A lot of modems encode more than one pair of values in the phase angle of the signal or in multiple signal levels. TouchTone encodes 4 bits per pair of tones. There's always a tradeoff between the number of states encoded, the reliability of the signalling (likelihood of a mistake in decoding or in the communication itself), and the time it takes to reliably decode the signal at the other end. As technology changes, it may become easier or harder to handle multiple states vs. raw speed.

uxorious

I would call that a digital version of Amplitude Modulation???? MarkS hit my first thought right on about being able to establish thresholds that are not easily corrupted.

"Kinda-sorta" along the same lines, a similar idea with transmitting light of a specific color through optical fiber to represent different types of data does exist. To transmit one of seven conditions, a bright RGB LED is focused into a length of optical fiber and a color sensor on the other end interprets the condition for a controller. So these "data types" are available as a "single data bit":

0=all off
1=red
2=green
3=blue
4=red and green
5=red and blue
6=green and blue
7=all 3 on

The LEDs are driven with a constant current source to prevent brightness levels becoming a factor in the color when using more than one LED. The "smart" transmitter consists of about 7 parts.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
~~ dRu ~~

Beau Schwabe

Oldbitcollector,

It's called QAM (Quadrature Amplitude Modulation), and is commonly used.


en.wikipedia.org/wiki/Quadrature_amplitude_modulation

Depending on the number of constellations, you can have 4-QAM, 8-QAM, 16-QAM, 32-QAM, etc. different amounts of throughput can be achieved with relatively low bandwidth requirements.

en.wikipedia.org/wiki/Constellation_diagram


Digital Cable TV I think uses a 64-QAM technique.

Although I'm not sure nowadays, but in the early 80's and 90's this technique was widely used for telephone modems and cause for the "boom" during that period where the throughput doubled over the same copper wires in a relatively short time.

Ethernet communication uses a form of this to obtain reasonable high speeds over copper, but it phases the signal over the 4-pairs. I.e. for Gigabit Ethernet, each twisted pair only has a throughput of 250kbit (1/4th of the Gigabit), then QAM is applied to each twisted pair so that a throughput of at least 250kbit is achieved on each pair. Depending on the constellation patterns used via QAM (can be variable) the actual bandwidth through the Ethernet cable can be quite low.

Scroll towards the bottom of this page under the description for "1000BASE-T details"
en.wikipedia.org/wiki/Gigabit_Ethernet

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Beau Schwabe

IC Layout Engineer
Parallax, Inc.

Post Edited (Beau Schwabe (Parallax)) : 5/22/2008 12:14:45 AM GMT

Oldbitcollector (Jeff)

There is truly no new idea under the sun!

Comments have inspired me to add some experimentation on this
to my "to-do" list! I could see a neat project for the multicolor LED setup.

Good reading in links! Thanks Guys!

OBC

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
New to the Propeller?

Getting started with the Protoboard? - Propeller Cookbook 1.4
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card? - PropDOS
Need a part? Got spare electronics? - The Electronics Exchange

stamptrol

OBC,

Not directly related to this thread, but it did prompt a trip to the Electronics Exchange.

I think the link in your signature area does not have it as www.warrantyvoid.us, so the link fails and has to be manually entered.

Cheers,

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Tom Sisk

http://www.siskconsult.com
·

Oldbitcollector (Jeff)

I believe I have that fixed now.. Although I never had an issue with it using Firefox..

OBC

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
New to the Propeller?

Getting started with the Protoboard? - Propeller Cookbook 1.4
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card? - PropDOS
Need a part? Got spare electronics? - The Electronics Exchange