Re: [Discuss-gnuradio] UCLA_Zigbee_phy examples on E100

[Marcus D. Leech]

On 14/09/2011 1:35 PM, ziyang wrote:
> Hello everyone,
>
> I'm new to gnuradio & usrp devices. I tried to update the 
> ucla_zigbee_phy examples "cc2420_txtest.py" and "cc2420_rxtest.py" to 
> work with UHD (see attachments), then I ran the codes separately on 
> two E100 devices but cannot get any packet from the receiver. To find 
> out the problem, I connected a vector sink directly to the 
> uhd.usrp_source in the receiver. Then I got some data but it seems 
> nothing came from the transmitter side, because even if I do not run 
> the transmitter, the values of the collected data does not change 
> much, most of which are smaller than 0.01.
>
> I have been using the E100 boards and RFX2400 daughter boards, with 
> UHD image 003.002.001.
> The options for the usrp devices are:
> center frequency: 2.475 GHz
> sample rate: 200 000
>
> Now I got confused by what happened, could someone have a look at my 
> codes and give me a tip about what might be the problem?
>
> Thanks in advance,
>
> Terry 
I don't know about the ZigBee codes specifically, but UHD-based "flows" 
have data that are scaled to {-1.0, 1.0}, and if the ZigBee code
  is expecting more "traditional" ranges {-32k, 32k}, it would likely 
get confused.

You should confirm reception using just uhd_fft.py, just as a 
first-order sanity check to see that there's some spectral content there.
  Once you've confirmed that, *then* you can start debugging the 
(complicated, probably) ZigBee stuff.