Wireless Laser Control - improving reliabilty / safety

[Lasermad]

SO far it sounds like .....

a) getting frequency allocated would be impossible

b) obtaining a chip to change frequency that would swap out or require minimal soldering would be hard to impossible

c) Qm wireless uses 2.4ghz ( stand to be corrected on this ) so its maybe not as much of a no-go as I imagined ?

So lets say i concentrate on staying on 2.4 , one way i imagine to make it safer is to increase Signal power .. kind of blasting the information thru so it has less chance of being interuppted ....that can be done on routers quite easy ... out on the net theres some software hacks to increase power therefore range ( apprently all BT routers are capable of 7 times power output they are set at, but are turned down by software to meet Uk specs ) .
HOWEVER at the laptop end either with built in WIFI or with added dongle i have never read or heard or an extra power dongle or a way or increasing power level.

I would also imagine its a one way street ? as regards information flow ..i cant imagine the routers sending much information back .. i would imagine its all one way TO the router/laser so i imagine its mainly the laptop/dongle that really needs the power increased.

[Lasermad]

Also just thinking is there ANY countries that DONT use 2.4 ghz for their routers ? ..maybe japan ( as a random example ) uses 2.7ghz and it might be a lot easier to simply buy in routers on a different frequency than try and mod existing ones , providing the frequency i not critical in the country you plan to use

[mixedgas]

[QUOTE=Lasermad;52613]SO far it sounds like .....

a) getting frequency allocated would be impossible

b) obtaining a chip to change frequency that would swap out or require minimal soldering would be hard to impossible

c) Qm wireless uses 2.4ghz ( stand to be corrected on this ) so its maybe not as much of a no-go as I imagined ?


first
use a war driving program to analyse channel use in your area, most people leave their lans on the default channel. or get one of those 45$ usb channel analysers.

There is one trick to "blasting" away. Dont increase the power, increase the directivity.
make it laserlike.

Ie a log periodic or yagi antenna, this drastically improves signal to noise and locks out sources not in your beampath.

two candidates so you dont get ripped off on ebay junk. Both sell to ham radio
keep the coax short and use a microwave coax cable, I can help you find a low loss coax.
watch the solder joints, keep the braid on as close to the joint as possible, and DONT splice them. Pasternack and other coax places sell the wierd connectors the FCC mandates to prevent antenna changes, or just go inside the case and skip the connectors.

WA5JVB, kent brittain, KENT ELECTRONICS, you want a YAGI, not his broadband log periodic. a Whopping 5$ and he has 900 in stock. you'd need some type 141 coax thats low loss at 2400, designed for ham use, so it covers both sides of the LAN band. keep the coax short short short, its lossey.

http://www.wa5vjb.com/products2.html
http://www.wa5vjb.com/prices.html

more gain: like too much. You could detect that signal ~10- 20 miles with this one.
MFJ Enterprises

http://www.radioworld.co.uk/~radio/c...1g-p-4727.html

Or go wokking away from this mess (sorry, could'nt resist thepun)

http://www.usbwifi.orconhosting.net.nz/



for the record, you run the risk of ticking off your national radio authority for doing this, but its not like they go around war driving on laser show nights unless there is a complaint. I like my ham license, although I rarely use it, so I disavow encouraging you to do the the MFJ 15 dbi one. I would not care much about the yagi pcb antenna though for indoors use.

3 dbi = 2x gain 10 dbi = gain of 10 so 15 dbi (decimals are a log function ) is approx a signal directivity gain of 20 , whooohooo, virtual amplification of power!

or go optical, a led, a photodetector and two fresnel lenses. they (those nutters who experiment with this) get ~5 miles with a red luxeon and a fresnel,and a pmt some times.

Steve

[mixedgas]

Also just thinking is there ANY countries that DONT use 2.4 ghz for their routers ? ..maybe japan ( as a random example ) uses 2.7ghz and it might be a lot easier to simply buy in routers on a different frequency than try and mod existing ones , providing the frequency i not critical in the country you plan to use

yeah, japan ,aisa, africa, OZ, russia.

Steve

[DZ]

How about this for wireless control of your projector!

http://www.pangolin.com/ubb/showflat...=0&page=0#1922

[loopee]

so if the QM uses a wireless router why cantwe?

The QM doesn't contain wireless at all, YOU supply the wireless adapter and attach it to the QM2000.net therefore YOU can connect whatever wireless device you like to it as long it supports Ethernet.

Quote:
Originally Posted by Lasermad
Also just thinking is there ANY countries that DONT use 2.4 ghz for their routers ? ..maybe japan ( as a random example ) uses 2.7ghz and it might be a lot easier to simply buy in routers on a different frequency than try and mod existing ones , providing the frequency i not critical in the country you plan to use
yeah, japan ,aisa, africa, OZ, russia.

All of these countries use 2.4Ghz and/or 5Ghz, the two spectrums are pretty much standard around the world for compatibility, with the only exception being the quantity of channels in use in each spectrum.

This link give a summary of channels and power settings allowed for different regions:- http://www.cisco.com/en/US/docs/wire.../winapdkh.html

So lets say i concentrate on staying on 2.4 , one way i imagine to make it safer is to increase Signal power .. kind of blasting the information thru so it has less chance of being interuppted ....that can be done on routers quite easy ... out on the net theres some software hacks to increase power therefore range ( apprently all BT routers are capable of 7 times power output they are set at, but are turned down by software to meet Uk specs ) .
HOWEVER at the laptop end either with built in WIFI or with added dongle i have never read or heard or an extra power dongle or a way or increasing power level.

"increase Signal power" isn't the smartest way to increase reliability as all you do is create multipath issues (among other things) that result in dropped packets and packet retries. This would be further increased in environments that contain lot of metal structures (like lighting rigs) that the radio waves can bounce off.
Like Mixedgas stated the best way to increase reliability would be to use directional antennas that are aligned properly.

Example. I have a local council which I have installed wireless data links for, these link stretch up to five kilometres and we are getting data rates from 54Mbps down to the 36Mpbs (surprisingly on one of the shorter links) and this isn't by blasting the signal its by using directional YAGI antennas. The council also use one of the links for connection to the DR site where they backup all their data.

One other issue is that blasting the signal is considered illegal in most countries and attract fines, some rather substantial
Most countries have what is called EIRP (Equivalent Isotropic Radiated Power) This EIRP defines the maximum amount of power that is allowed to be transmitted from the radio transmitter.

One thing that we all need to remember when connecting to something like the QM2000.net device is that it's using TCP/IP for it transmission protocol and that in it own right is very resilient for data transfer (just look at how well it works across the internet ), also the I imagine the QM2000.net device would buffer most of the data before being sent onto the QM2000 board.

So the only issue we need to consider is reliability for things like shutter control and emergency shutdown operations not so much the data transfer.

This could be done with something like a car alarm security remote based on 433Mhz (I think) and being coded would mean that it's also secure

[andy_con]

How about this for wireless control of your projector!

http://www.pangolin.com/ubb/showflat...=0&page=0#1922

now that is fooking cool!!!!

if only you could get a symbian application to install on a nokia then use it with bluetooth in laptops and phones

[loopee]

now that is fooking cool!!!!

if only you could get a symbian application to install on a nokia then use it with bluetooth in laptops and phones

You can get VNC for Symbian http://symvnc.sourceforge.net/index.html

[andy_con]

awesome, but i dont totally understand what i have to do

ive read this just dont get it all

http://www.pangolin.com/ubb/showflat...=0&page=0#1922

anyone help?

[loopee]

awesome, but i dont totally understand what i have to do

ive read this just dont get it all

http://www.pangolin.com/ubb/showflat...=0&page=0#1922

anyone help?

What part don't you understand?

1. Install a version of VNC on the PC running the QM2000 board and configure.
2. Install the Symbian VNC on the phone
3. configure the wireless access point
4. configure the phone to connect to the access point
5. configure VNC the phone and connect

P.S. This will not work on a QM2000.net solution, only on a QM2000 system with a PC