wireless network - more listeners

meereck · Joined: 09 Nov 2006 Posts: 173

Hello everyone,
I would like to build a device which communicates with others via a wireless network. Prerequisite is a possibility of more devices receiving a packet (no point to point).
What network and peripherals for a PIC are suitable?

thank you,
Best regards M.

rnielsen · Joined: 23 Sep 2003 Posts: 852 Location: Utah

http://www.maxstream.net/products/xbee/xbee-pro-oem-rf-module-zigbee.php

I've used these modules in a couple of projects and they are fairly inexpensive. They have the ability to, in default mode, act as a serial cable between two devices. They can, also, be made to be a point-to-multipoint or multipoint-to-multipoint device. I had to get a MAX3371 interface part to convert the PIC's 5V signal to the XBEE's 3.3V signals. It took me a couple of calls to their Tech Support to figure out how to do the point-to-multipoint but now that I've got the hang of it it's fairly simple to make things work.

Ronald

meereck · Joined: 09 Nov 2006 Posts: 173

thank you very much for an interesting reply.
I did some background reading about ZigBee. The problem is that I need to send a data to all devices in range of a sender and I don't want to be concerned with addresses, since I just need something like a broadcast packet. In other words I just need to send a packet to everyone who is able to receive it.
Therefore I need something which is not based on addressing.

Is the ZigBee capable of this?

Hope I explained it clearly.
cheers M.

Foppie · Joined: 16 Sep 2005 Posts: 138 Location: The Netherlands

The Maxstream modules are able to broadcast. I believe this is only in the multi-point-to-point version but it might also work in the zigbee version. (hardware is the same for both function, you only need to flash the chips with new software to support the different versions).

Which ever version it is that supports the broadcast, you might find it usefull.

Hope this helps, Jos

jecottrell · Joined: 16 Jan 2005 Posts: 559 Location: Tucson, AZ

Actually, with the Maxstream radios, there is no need to reflash the radios for the configuration you describe. A simple protocol in your PICs would allow for the reception of the broadcast packet.

The X-CTU software to reflash the radios is easy to use and allows for changing the default settings like: BAUD, ID's, channels, etc.

I would recommend them highly and they would be very suitable for your application.

John

Foppie · Joined: 16 Sep 2005 Posts: 138 Location: The Netherlands

I just looked it up in the maxstream zigbee manual and it says it has the broadcast functionality available.

So you can use the maxstream zigbee modules.

kd5uzz · Joined: 28 May 2006 Posts: 56

I just bought some of these from SparkFun. They've got an SPI interface, handle error detection and correction, 250kbit data rate. Can be configured to RX from 6 transmitting devices at once. Very cool.

http://www.sparkfun.com/commerce/product_info.php?products_id=705