[REQUEST] Mesh Topology For Wireless Sensor Network

[Sobakava]

Hi All,

I want to build short range Wireless Sensor Network based on ASK or FSK RF Transceivers. Recently I have used NRF9E5 from Nordic Semi. It has 32bit unique ID filter for receiving packets. Anyway, seems there are several similar ICs in the market.

What I want to do is, collect sensor readings from the field using my modules. But I also want to extend my coverage (range) with every node I install into the field. Each node should capable of being a repeater as well.

The distance between nodes could be up to 200-250meters. And I can't use ready-made mid range modules ie Xbee. I want to design it from scratch.  

anyone knows about a library, easy to implement protocol for this kind of approach?

Thanks!

[monkey]

That sounds like quite a challenge, and I understand that zigbee or ip based 6lowpan may be too complex.

To act as repeaters I see you have two options - either have the nodes act as "dumb" routers resending any packets not for them ( perhaps you can choose the addresses of each node so it has a fixed route table ( i.e. devices "know" what the layout of all the noes are and what node is adjacent ) or you have to make each node have its own "mini router" that has a "discovery" mode to poll and make a table of all its adjacent nodes and their rcvd signal strengths. This is a lot more complex.

So I suggest it would be much simpler if the layout is fixed and known as there would be no need for router "discovery".
Hope this helps a little...

[hate]

I used 'mrf49xa' from microchip in the past. I don't know its range but I found it quite functional for a wireless node, you may consider. 'monkey' has a good point for system design and to design an efficient system from scratch, you'll need either a chip that is capable or a designer experienced with RF (that'll be you). So I suggest starting with a working system and breaking it into parts to redesign.

[mexpcb]

another type of topology or approach is to learn a bit about MANET, those are for "nodes" with mobility but it's basically the same principle you wanted to have, some nodes may act in adhoc mode or repeater...

i have some books about wireless sensor if someone is interested please let me know....

[movf_jmpz]

Here is arduino based AVR implementation (HopeRF's RFM22) in C++ :

http://www.airspayce.com/mikem/arduino/RF22/index.html

[millegps]

Hello,

I suggest you to take a look to ti.com website, under wireless connectivity section.
They have at least 3 or 4 free stacks available.

SimpliciTI comes with full source code, so you can port to your platform, even if they have also ICs of course.

FYI, I used cc1101 in UHF band (868MHz) within your range

[chicane]

Looks like this is an old thread being responded to.

Just in case there is still interest, I would consider
checking out Contiki
Here is the wiki
https://en.wikipedia.org/wiki/Contiki

The open source project webpage
http://www.contiki-os.org/

It's been awhile since I have kept up on this, looks like it keeps moving ahead.

There was also tinyOS (www.tinyos.net) but it has fallen behind the advancements contiki has made.

[card_claud]

I don´t know if add up something but there are the NRF24L01 as well, and Mr Brennen (http://blog.diyembedded.com/2007/06/tutorials-1-3-for-pic-completed.html) made available all C routines.

Cláudio.