[uracoli-devel] Question regarding LQI and ED values

[Eric Jennings]

Hi there-

First time post to this list, really love uracoli thus far!  I have a couple 
questions, but first, my setup:


I have Wibo running on two Sparkfun ATMega128rfa1 development boards--one as 
host, and the other as an end node.  I have the bootloader loaded on both and 
can ping the end node from the host, works great!  

I decided to add a bit of info to the ping output, to see how my LQI and ED was 
looking.  The ping result used to look like this:

        OK {'short_addr':0x01, 'boardname':'sparkfun', 'swversion':0x01, 
'crc':0x40C9, 'pagesize':0x100,

And I added the two addl. fields so it now looks like this:

        OK {'short_addr':0x01, 'boardname':'sparkfun', 'swversion':0x01, 
'crc':0x40C9, 'pagesize':0x100, 'lqi':255, 'ed':0}


Super that I can now see how the RF performance is looking.  I have two 
questions though:

One, my LQI is almost always at 255 but ED is at 0.  Once in a while LQI kicks 
down to 240, or 215, and once in a while to something like 116.  I figure this 
is just noise or whatever.  But why is ED always at 0?  I read the blogpost 
regarding LQI/ED relationships:  
(http://uracoli.blogspot.com/2010/05/playing-with-xmplradiorange.html), but I'm 
curious why I can't seem to get a positive number for the ED value?

Two, about one in 20 times or so, as I'm pinging the end node, I'll get an "ERR 
ping timeout".  Is this typical for the LQI/ED values I'm seeing? 


Also, a big thanks to Eric Weddington for giving me the heads up about the 
uracoli library when we met at the Make Hardware Innovation Workshop in May!  
We're prototyping uracoli for an open hardware project, and so far we're super 
happy with what we've seen so far.

Best regards-
Eric