Timeline for How can I send one bit one mile with one battery?
Current License: CC BY-SA 3.0
20 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jan 17, 2015 at 16:53 | vote | accept | TheNoonMoose | ||
| Jan 17, 2015 at 2:18 | comment | added | Russell McMahon♦ | ... Or low speed telemetry or data if allowed. Arduino .... :-). They say " ... In the United States of America, uses of the ISM bands are governed by Part 18 of the FCC rules, while Part 15 contains the rules for unlicensed communication devices, even those that share ISM frequencies ..." | |
| Jan 17, 2015 at 2:16 | comment | added | Russell McMahon♦ | @TheNoonMoose Choose another good answer - and wait a few days - you may get even more good answers. A look at the ISM bands for your area will show what is legal. There are also sometimes bands in the VHF spectrum for ISM that are little known to low bandwidth. ISM band info here - wikipedia. I'd guess that 6.780 MHz is liable to be almost unknown and 13.567 MHz equally so. Both are very low bandwidth - about 1 voice channel (if allowed) or morse. | |
| Jan 16, 2015 at 17:58 | comment | added | TheNoonMoose | @RussellMcMahon Bonnaroo. If you can make an answer about "morse" on a frequency I can use without a license I would accept that. | |
| Jan 16, 2015 at 13:22 | comment | added | Russell McMahon♦ | bluehaze.com.au/modlight/OpticalComms4Amateur79.htm | |
| Jan 16, 2015 at 13:18 | comment | added | Russell McMahon♦ | Too many ideas here.| Disney manage 50mm| and [Oh yes ! ](qsl.net/wb9ajz/laser/laser.htm) | and [Excessively tidy ](qsl.net/wb9ajz/laser/Kerry/Kerry%27s_OCB.html) | |
| Jan 16, 2015 at 13:16 | comment | added | Russell McMahon♦ | .... or even a white visible LED but ability to filter helps) can give you vast range. As physical beam angle widens ease of comms connection increases. | Thinks - 1 mile red LED, a Watt or few - photo detector in a shielded tunnel or gallery to reduce ambient light. Sounds doable. Easily tried. Probably manage voice coms. Pocket size makes non directional RX harder. Worth a play. |FWIW with proper lenses and at night people manage voice coms out to about 50km | BUT workable is probably to find a common high point (or a blimp or few) and use sunlight and pocket mirrors :-) | |
| Jan 16, 2015 at 13:05 | comment | added | Russell McMahon♦ | .... at a stable location in any band will allow a characteristic pattern to be picked out by ear at well under the noise level. Amateur morse code has always managed this.| Slow tone on a channel with a PLL detetctor would likely handle say 1 bps in vast noise and 0.1 bps in any amount of noise using simple majority presence voting. eg look for 400 Hz or 700 Hz - was there a predominance of either of these in the last second? | Correlation on two channels | SMALL tower - say 10 foot stick with an IR diode (or even a red LED - .... | |
| Jan 16, 2015 at 12:59 | comment | added | Russell McMahon♦ | @TheNoonMoose Burningman? Wrong continent for the UK hippiefests :-). Many potential options. Some easier. Almost certainly legal ISM (Industrial Scientific Medical) bands are available that have too low bandwidth for normal comms use. Old ISM/Radio control band at about 13.6 MHz in some admins. Multi channels at 27 MHz still used. "When the Robot points north ...". | Your local hams may be delighted to loan a spread spectrum low bandwidth unit that swims happily in the 2.4 GHz WiFi noise. | You may get better results with 5.x GHz WiFi - possibly not. | A narrow bandwidth signal "morse" .... | |
| Jan 16, 2015 at 12:52 | comment | added | Russell McMahon♦ | @KyranF Your question is exactly what he IS asking. IF the airwaves are full, how would I ... . There are many potential answers :-). | |
| Jan 16, 2015 at 7:14 | answer | added | Eric Cope | timeline score: 2 | |
| Jan 16, 2015 at 7:00 | answer | added | paul | timeline score: 1 | |
| Jan 16, 2015 at 4:59 | comment | added | GR Tech | What about to use a wireless USB network adapter like this amazon.com/Etekcity-Wireless-Network-Adapter-Antenna/dp/… | |
| Jan 16, 2015 at 3:29 | answer | added | Ambiorix | timeline score: 1 | |
| Jan 16, 2015 at 2:29 | comment | added | TheNoonMoose | @Some Hardware Guy ...I can't come up with a good reason a tethered "blimp" wouldn't be perfectly acceptable in my situation. Hmm. | |
| Jan 16, 2015 at 2:26 | comment | added | horta | What comes to mind is something like a smart meter communication method for remote areas where a low amplitude signal is sent multiple times at relatively lower frequencies. By the time the signal reaches the receiver, the signal is below the noise floor. The receiver is designed to track the frequency and when it compiles the noise over time, it can extract the information back out. | |
| Jan 16, 2015 at 2:23 | comment | added | TheNoonMoose | @KyranF my thought process was, there might be some frequency- like says 433MHz- that isn't used by those common types of personal communication but that I could use, and that restricting the bandwidth of the frequency could possibly simplify the design. | |
| Jan 16, 2015 at 1:49 | comment | added | Some Hardware Guy | Just for you guys to communicate? What about a 433mhz radio at low bit rate? Or a teathered blimp and some modified laser pointers. Kidding on the last one, sort of :) | |
| Jan 16, 2015 at 1:47 | comment | added | KyranF | If the airwaves are full of traffic already, how do you expect your simple on/off Morse Code style thing to work properly without super awesome filtering skillz? I guess a very high quality RF transmit/receive pair with extremely good band-pass filtering could make use of an (illegal) unused frequency and it will probably work okay. | |
| Jan 16, 2015 at 1:19 | history | asked | TheNoonMoose | CC BY-SA 3.0 |