Re: [Discuss-gnuradio] OOT Module Not Working Properly

[Jeff Long]

Noise amplitude is 1.0, so you are generating a lot of noise.

The following two lines in your block are not right. 'c' is computed but 
not used. 'i' is the original value, not the log. Not sure about the 
scaling factor (1024).

#converts 1024 values stored in in1 to dB and stores them in c
c = math.log10(i/1024)

#checks if any of the values stored in c are greater than a threshold value
if i > 70:

On 01/12/2018 02:47 AM, Tellrell White wrote:
> Hello Guys
>
> I'm creating a customized block in the GNU Radio framework using python 
> that takes in a number of input items and once that number of input 
> items surpasses a certain number, 1024 of the input items are taken and 
> stored into an array, and then those items are converted to dB and 
> lastly compared to a threshold value, 5 in this case. If any of the 
> values are greater than the threshold value, a message is printed 
> indicating a signal is present, and if none of the values are greater 
> than 5, this is indicated with a message stating "No signal is present".
>
> In the flow graph attached, I'm using a cosine source and a gaussian 
> noise source to test my block in two different scenarios.
>
> In scenario 1, I run the flow graph with both signal sources and I 
> expect to receive a message stating "A signal is present" because the 
> power of the signal will be greater than the threshold.
>
> In scenario 2, the cosine source is disabled and only the noise source 
> is runing. In this scenario I expect to get a message indicating no 
> signal is present because the calculated power will be lower than the 
> threshold.
>
> Scenario 1 works, however, scenario 2 doesn't work no matter how high I 
> raise the threshold value and, at this point, I'm not quite sure as to why.
>
> Any help would be appreciated. Both the .py script for the oot block and 
> the .grc file are included.
>
> Tellrell
>
>
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