Need advice on wireless network

Hello,
  I am trying to build a wireless sensor controller where the sensors
are distributed and a central device is able to read the status of
every node.  My knowledge about wireless networks is novice at best.
I was looking into zigbee and then got hold of TI's CC2500 development
tool.  I  ran the demo but the distance from the sensor to the pc was
too short for my application.  I was able to go less than 15 feet
(indoors) before I lost connection.  I was practically still in the
same room except that there was an end table in the line of sight
between the receiver and transmitter.  Is this something typical of
these devices?   I am looking for something in the range of 20-30m
indoors.

  Any hints or ideas?

Thank you,

A

On Feb 25, 10:02=A0pm, amerdsp <amer...@hotmail.com> wrote:
> Hello,
> =A0 I am trying to build a wireless sensor controller where the sensors
> are distributed and a central device is able to read the status of
> every node. =A0My knowledge about wireless networks is novice at best.
> I was looking into zigbee and then got hold of TI's CC2500 development
> tool. =A0I =A0ran the demo but the distance from the sensor to the pc was
> too short for my application. =A0I was able to go less than 15 feet
> (indoors) before I lost connection. =A0I was practically still in the
> same room except that there was an end table in the line of sight
> between the receiver and transmitter. =A0Is this something typical of
> these devices? =A0 I am looking for something in the range of 20-30m
> indoors.
>
> =A0 Any hints or ideas?

Checkout Chipcon website.
I have used CC1010 for both Rx and Tx. It was good for short distance
communication.
Check if it can be tweaked to your requirements.

Karthik Balaguru

>Hello,
>  I am trying to build a wireless sensor controller where the sensors
>are distributed and a central device is able to read the status of
>every node.  My knowledge about wireless networks is novice at best.
>I was looking into zigbee and then got hold of TI's CC2500 development
>tool.  I  ran the demo but the distance from the sensor to the pc was
>too short for my application.  I was able to go less than 15 feet
>(indoors) before I lost connection.  I was practically still in the
>same room except that there was an end table in the line of sight
>between the receiver and transmitter.  Is this something typical of
>these devices?   I am looking for something in the range of 20-30m
>indoors.
>
>  Any hints or ideas?
>
>Thank you,
>
>A
>

I've used the zigbee before, the range was good but I remember line of
sight was an issue.  I was surprised too.

On Feb 25, 12:12=A0pm, karthikbalaguru <karthikbalagur...@gmail.com>
wrote:
>
> Checkout Chipcon website.

Which is now owned by TI.

amerdsp wrote:
> Hello,
>   I am trying to build a wireless sensor controller where the sensors
> are distributed and a central device is able to read the status of
> every node.  My knowledge about wireless networks is novice at best.
> I was looking into zigbee and then got hold of TI's CC2500 development
> tool.  I  ran the demo but the distance from the sensor to the pc was
> too short for my application.  I was able to go less than 15 feet

Did you design your hardware or just copied what was easy.

You need to design your own hardware to get the distance you want.

good luck

donald


> (indoors) before I lost connection.  I was practically still in the
> same room except that there was an end table in the line of sight
> between the receiver and transmitter.  Is this something typical of
> these devices?   I am looking for something in the range of 20-30m
> indoors.
> 
>   Any hints or ideas?
> 
> Thank you,
> 
> A

On Feb 25, 2:54 pm, donald <Don...@dontdoithere.com> wrote:

> Did you design your hardware or just copied what was easy.
>
> You need to design your own hardware to get the distance you want.

I am planning to design my own but for now I just ran the demo that
came with the CC2500 chip.  Thats when I ran into the distance/range
problem. I was just trying to get a feel to what I can or cannot use.
What should I look for when I am design?  Any ideas?

Thank you,

On Mon, 25 Feb 2008 13:41:07 -0800 (PST), in comp.arch.embedded
amerdsp <amerdsp@hotmail.com> wrote:

>On Feb 25, 2:54 pm, donald <Don...@dontdoithere.com> wrote:
>
>> Did you design your hardware or just copied what was easy.
>>
>> You need to design your own hardware to get the distance you want.
>
>I am planning to design my own but for now I just ran the demo that
>came with the CC2500 chip.  Thats when I ran into the distance/range
>problem. I was just trying to get a feel to what I can or cannot use.
>What should I look for when I am design?  Any ideas?
>
>Thank you,
I'd look at the antenna design. A good antenna system can make a lot
of difference


martin

On Mon, 25 Feb 2008 09:02:35 -0800 (PST), I said, "Pick a card, any
card" and amerdsp <amerdsp@hotmail.com> instead replied:

>  I am trying to build a wireless sensor controller where the sensors
>are distributed and a central device is able to read the status of
>every node.  My knowledge about wireless networks is novice at best.
>I was looking into zigbee and then got hold of TI's CC2500 development
>tool.  I  ran the demo but the distance from the sensor to the pc was
>too short for my application.  I was able to go less than 15 feet
>(indoors) before I lost connection.  I was practically still in the
>same room except that there was an end table in the line of sight
>between the receiver and transmitter.  Is this something typical of
>these devices?   I am looking for something in the range of 20-30m
>indoors.

That really shouldn't be a problem with the right antenna. An
802.11G network has a practical range of about 30 meters with a
stock antenna from the box. Use a high gain, unidirectional antenna
and some people have gotten as much as 20km with full duplex.

Go here: http://www.wafreenet.org

They have several "how to" projects there; all free. They've been
playing around with wireless in a big way for years now. There are
both unidirectional and omnidirectional antennae there for you to
experiment with. The Bow Tie, bi-quad antenna might suit your needs.

http://martybugs.net/wireless/biquad/

Have fun.
--
Ray

amerdsp wrote:
> On Feb 25, 2:54 pm, donald <Don...@dontdoithere.com> wrote:
> 
>> Did you design your hardware or just copied what was easy.
>>
>> You need to design your own hardware to get the distance you want.
> 
> I am planning to design my own but for now I just ran the demo that
> came with the CC2500 chip.  Thats when I ran into the distance/range
> problem. 

Your not understanding whats going on here.

This is not a problem.

The board you tested was not designed for your application.

It was designed as a demo.

Your application requires distance, this board was not designed for 
distance.

As has been suggested, an antenna will help.

But YOU need to design it for the application,

Or you could just buy an off-the-shelf unit that matches your requirements.

donald




I was just trying to get a feel to what I can or cannot use.
> What should I look for when I am design?  Any ideas?
> 
> Thank you,
> 

On Feb 25, 5:02 pm, donald <Don...@dontdoithere.com> wrote:
> amerdsp wrote:
> > On Feb 25, 2:54 pm, donald <Don...@dontdoithere.com> wrote:
>
> >> Did you design your hardware or just copied what was easy.
>
> >> You need to design your own hardware to get the distance you want.
>
> > I am planning to design my own but for now I just ran the demo that
> > came with the CC2500 chip.  Thats when I ran into the distance/range
> > problem.
>
> Your not understanding whats going on here.
>
> This is not a problem.
>
> The board you tested was not designed for your application.
>
> It was designed as a demo.

The kit is marketed as a development kit not a demo board. Since this
kit is meant to advertise the best in the CC2500 chip, I assumed they
would put a decent antenna to stand out from the crowd.

>
> Your application requires distance, this board was not designed for
> distance.
>
> As has been suggested, an antenna will help.

I agree the antenna is very important.  What I was asking is that
perhaps the CC2500 is not meant to have long range transmission.  You
can use the best antenna out there, but if you do not have the power
to drive it nothing is going to happen.

>
> But YOU need to design it for the application,

Yes, indeed.  Thats what I am planning to do but not before I know
that the hardware I am using is able to get the ranges I want.

As I said, RF is not my strength and I thank you for your input.

>
> Or you could just buy an off-the-shelf unit that matches your requirements.
>
> donald
>
> I was just trying to get a feel to what I can or cannot use.
>
> > What should I look for when I am design?  Any ideas?
>
> > Thank you,