Jee Labs Talk

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1. hugo
   

   Hi guys,

   Seeing the Arduino (via Adafruit) and now the JeeNode, I'm with an itch to play with electronics again. First I was thinking of getting the Arduino+XBEE, but now I've found out JeeNode which apparently will give me more possibilities while running on AAs.

   I'm thinking about buying a Jeelink, a JeeNode and a USB-BUB cable. With this I can get started, right?

   Even though there's a lot of information on the blog posts and forums, but there are a couple things I'd like to understand:

   Network related:

   - When several JeeNodes are in range, and one of those transmits something, do they all receive the same packet and then analyze the header to decide if the packets belongs to them? (Or they transmit in different frequencies for each device they want to address?) - Why can't the JeeNode have mesh networks? The device is too small to fit the complex code it would take? - If there is no mesh, the basic model I imagine would be something like: several JeeNodes spread over a 100m radius area, perhaps with a central JeeLink connected to a PC to report data back to you. Is this right?

   Automation:

   - The JeeNode is commonly used for sensoring. Can the JeeNode be used for wireless (cheap, no need to destroy walls, no ugly wires) automation too? Why would this be a bad idea? Commercial automation solutions are very expensive and I'd love to implement an "intelligent house" by myself, little by little.

   Well, I know its a lot to ask. Thanks in advance!

   Hugo

   Posted 06/08/2010 01:58:57

2. stef007
   

   Hi hugo,

   if you want to start cheaper then you have sufficient material when you buy 2 jeenodes and 1 usb-bub. The jeelink is more expensive but it's usefull to stick in your NAS or server without needing the BUB.

   Regarding your questions:

   1. normally you put all your jeenodes onto the same Mhz band and in the same group. In that case they do indeed all receive the packets and filter out which ones are targetted for them specifically or were broadcast for all to get (using header flags and node id). This filtering is done in software, in JC's RF12 lib.

   2. I'm not sure about this one but I think that mesh support is not there simply because JC or anyone else did not create a library for that. I don't know if the hardware is really missing things to support mesh networks or not. Ofcourse, the available flash size for your programs would be reduced as I think the mesh lib would consume more memory. Perhaps someone else could answer this one for you (more specifically JC when he gets back).

   3. 100 meter is perhaps a bit too much and certainly unrealistic in house. For me it seems more like 20 meters max in all directions through 1 or several walls/concrete floors. But yes, the "star" would be your form. Perhaps you could increase the range by putting jeenodes as repeaters. Unsure if code for this already exists are not.

   4. Well in fact I'm also using it for automation: I've actually built one inside my kitchen ligths where it listens for commands over RF to switch two relays on or off. Ofcourse you cannot just connect relays to the jeenode outputs. I'm using an output plug to provide the power to power the relays.

   Posted 06/08/2010 09:05:53

3. hugo
   

   Hi stef,

   The 100m was just an example because I read that was the typical range. To make things worse, around here (Brazil) most houses (mine included) have the internal walls made of brick.

   The RF12 lib is uploaded together with my "application" code every time I program the device? (I'll probably like to play with RF12 just to see when things stop working)

   Ok, so I'll resist the temptation to buy the nice looking JeeLink and will buy 2 JeeNodes for now!

   Thanks a lot! - Hugo

   Posted 06/08/2010 12:50:06

4. stef007
   

   hugo,

   remember that if you want to run the rf12demo code and see serial output for each of them, you will need two BUBs or better choose a jeelink or jeenode USB version for one of them;-) With only 1 connected to your pc, the other will have to get external power and shows its output another way (LED, ...) The rf12 demo code is loaded standard by JC in new Jeenodes and jeelinks.

   The RF12 lib is uploaded together with your app only if you use its functions. So if you use the rf12 hardware and choose to use JC's lib for it, then yes parts or whole the rf12 lib will be uploaded as well.

   Posted 06/08/2010 14:50:07

5. hugo
   

   Oops, the order is placed now! My idea was to power the second one from batteries/old cellphone charger and its output would be transmitted to the one connected to the PC.

   Posted 06/08/2010 14:52:11

6. stef007
   

   Ok, so your jeenode on battery sends something over RF to the one connected at the PC. I suppose you will be running a custom app in the one on battery and possibly the rf12demo app in the one connected to the PC. No problemo.

   Posted 06/08/2010 15:18:26