My goal is to have multiple XBee modules send data back to the same base module. Is this easily attainable with normal modules, or do I need something different?
Also, I was wondering is it fairly simple for one XBee module to go from recieving data from multiple modules, to then sending data to a seperate module?
Any advice would be appreciated, thanks
Yes and yes. This is what XBees were designed to do.
First, there are four different protocols (firmware) that can be run on two different XBee hardware modules. You will need to study the pros and cons of each to decide which to use.
It does sound as if you need a Mesh network. One XBee is the coordinator and is connected to the PC com port. This could be called the ‘base’ and is responsible for creating the network.
Next would be routers that can relay data to the coordinator from other XBees that are out of range of the coordinator. They can also send their own data to the coordinator. Last are End devices that don’t relay data.
Depending on which protocol you use there may not be any real difference between routers and end devices. On some protocols an End device will always sleep most of the time and awaken periodically to send data.
Do look in this forum for a thread titled "Better XBee Documentation’ for links to more info.
While i haven’t been able to locate that particular thread, ive done a bit more reading on the xbee modules. Unfortunately i’m still a little confused about which modules/firmware i need to purchase. Maybe this is because im still a little confused about what the xbee modules can do, and what i require of them…
I’ve read that the DigiMesh firmware includes “routing” capabilities. What exactly does this mean? My goal is to have multiple modules sending data back to a base module. From what i’ve read i think i can just use the AT commands to get started, and include my own way of distinguishing between which module is sending data, within the packet. As i will be sending a very small amount of data this doesnt sound like a problem.
Unfortunately I’m a bit pressed for time, so i was wondering if somebody might suggest a hardware/firmware version to start out with? It doesnt sound like what im trying to accomplish is very complicated, I’m just not entirely sure where to start!
Here is the thread:viewtopic.php?f=13&t=17745&hilit=+better+xbee+documents
There are many other XBee threads discussing the questions you have and will help you in deciding what you need them to do.
Questions to help:
1- How far away are the remote XBees from the base? Can all of the remotes XBee’s connect directly to the coordinator (base) or do they need to be relayed (routed through another XBee) due to being out of range of the base?
2- Do any need to be powered from a battery? If so could they sleep to reduce current?
3- How much data total needs to be received at the base? Is the received data time sensitive
Thanks, ill do some more reading there.
My application is very simple. The distance will not be to far…from one room to another in a small apartment, possibly through a floor, i would imagine << 100ft, so there should be no need for a relaying module. I’m guessing this is what is meant by having routing capabilities? The devices will be wall powered, so there is no immediate concern for low power consumption. There will be a very small amount of data being sent back and forth…no more than 1 byte!
Seems that the XBee Series 1 modules running 802.15.4 firmware will do all you need. There is also the most information for hobbyist on this module/firmware both here in the Sprakfun forum and many other web sites.
Thanks Waltr, thats what i was thinking for the most part. The series 1 doesnt seem to transmit quite as far, but for my application i dont think it should be a problem. It also doesnt seem like i need the digimesh firmware, so the 802.15.4 sounds acceptable. Thanks again for the help!
Series 1 XBee can be purchased as non-PRO or -PRO. The latter is 60mW as compared to non-PRO which is 1-2mW.ecloney:
Thanks Waltr, thats what i was thinking for the most part. The series 1 doesnt seem to transmit quite as far, but for my application i dont think it should be a problem. It also doesnt seem like i need the digimesh firmware, so the 802.15.4 sounds acceptable. Thanks again for the help!
Series 2 is quite a different product - being ZigBee mesh oriented and much more complex.
No range/RF differences of note between Series 1 and 2.