Page 1 of 1

Bluetooth Class 1?

Posted: 03 Mar 2011, 12:46
by ricardocrl
I see that Bluetooth device is limited to distances around 10 meters, beause of being of class 2.

Could we extend this limit to class 1? Is the class implementation possible to change somehow, programmatically? Or is it hardware setup?

Thank you all.

Re: Bluetooth Class 1?

Posted: 03 Mar 2011, 12:56
by gloomyandy
It is part of the hardware. However if you use a class 1 dongle on your PC then you may get greater distances. Class 1 devices use higher power output and are often more sensitive on the input side. I use a class one device and get very good coverage around my house and garden (even with the walls etc.). One of those things that you probably just have to try and see what happens...

Andy

Re: Bluetooth Class 1?

Posted: 03 Mar 2011, 13:07
by ricardocrl
Oh, that seems a really good new!

Do you know if the distance coverage is affected by the number of bluetooth connections to the same dongle?

Re: Bluetooth Class 1?

Posted: 03 Mar 2011, 13:17
by gloomyandy
Sorry no idea, but I suspect it may well be. But these days that entire spectrum is pretty busy in most locations what with WiFi, dect, Bluetooth and who knows what else...

Re: Bluetooth Class 1?

Posted: 03 Mar 2011, 17:52
by mrblp
Hello,

sorry but I have bad news for you:
gloomyandy wrote:It is part of the hardware. However if you use a class 1 dongle on your PC then you may get greater distances. Class 1 devices use higher power output and are often more sensitive on the input side.
The standard only differencates transmitting power - so I dont belive the connection between a class 1 and a class 2 device will get a lot further that between two class 2 devices. There will of course be different distances between different devices of different manufactures - but that is because of the different hardwares. RF is a bit voodoo ;-) (That means: RF is not easy to design to work under all circumstances reliable.)

Bye - marvin

Re: Bluetooth Class 1?

Posted: 03 Mar 2011, 23:18
by gloomyandy
As I said in my experience (and I've used a lot of Bluetooth devices, I've got ten here at the moment), devices that implement class 1 often have a more sensitive receiver/antenna as well as a higher power output. This tends to give give a longer overall range when used with an NXT. This is not guaranteed, but I have four class 1 devices here and all of them have a much greater than 10m range when talking to an NXT. The six class two devices I have give a much shorter range(I doubt if it is even 10m).

Andy

Re: Bluetooth Class 1?

Posted: 07 Mar 2011, 09:35
by ricardocrl
Actually I found the same information that gloomyandy provided, on wikipedia (http://en.wikipedia.org/wiki/Bluetooth#Uses):
In most cases the effective range of class 2 devices is extended if they connect to a class 1 transceiver, compared to a pure class 2 network. This is accomplished by the higher sensitivity and transmission power of Class 1 devices.
Thank you all for the info! ;-)

Ricardo

Re: Bluetooth Class 1?

Posted: 07 Mar 2011, 19:59
by mrblp
Hello guys,
gloomyandy wrote:This is not guaranteed, but I have four class 1 devices here and all of them have a much greater than 10m range when talking to an NXT. The six class two devices I have give a much shorter range(I doubt if it is even 10m).
ricardocrl wrote:Actually I found the same information that gloomyandy provided, on wikipedia (http://en.wikipedia.org/wiki/Bluetooth#Uses):
OK I understand the difference here. I followed the link of the wikipedia cite and the difference was 25 m to 20 m. And Andy, the difference is about 8 m to 12 m between your class 1 and class 2 dongles? This may of course be. You also get different ranges by changing the direction of the devices to each other and so on.

I supposed people are expecting ranges about 75 m with a class 1 dongle using with a class 2 device. And that will never be reality - except the class 2 device is labeled wrong ;-)

Sorry for this misunderstanding...

Bye - marvin

Re: Bluetooth Class 1?

Posted: 07 Mar 2011, 22:24
by gloomyandy
Hi,
No I would say the difference is more like 8m with class 2 and 20+m with class 1, this is also going through walls... My standard test is to put the dongle in my computer in my study which is at the front of the house. Then walk off down the garden (at the back of the house), until I reach the point at which I can no longer connect and talk to the NXT. With a class 2 I often don't get out of the house (signal passing through 2 internal walls). With the class 1 devices I normally get well down the garden (at least 20m, plus the same walls)... Obviously this varies from device to device but with the NXT these are the sort of results I see... Sure you are not going to get 75m but I didn't say you would...

Andy