Hi Kyle, many thanks. i successfullly run fft peak it can get the index of peak but i want the frequency value not only the fft index. it seems it is difficult to use gnuradio block to compute the frequency from fft index because it need to deal with the top half part and the bottom half part of the band. so i think of modify fft peak block. the source code of fft peak block is all python and i don't know how to insert my code. it seems the max fft index connect to a null sink named null_1. how to insert code between the connection? and i also need to pass the center frequency and the frequency band to the block which seems defined in the xml file?
<http://aka.ms/weboutlook> ________________________________ From: Kyle A Logue <kyle.a.lo...@aero.org> Sent: Wednesday, December 2, 2020 12:48 AM To: james jordan <james.jordan....@hotmail.com>; discuss-gnuradio@gnu.org <Discuss-gnuradio@gnu.org> Subject: Re: how to auto detect peak frequency in QT FFT sink just did a quick test, couldn't be simpler [cid:6a484104-b817-47bc-b349-49ea6aaca429] max_i reports the argmax of the fft, with wrapping So in the above example: * 1 kHz -> 1 * 5.5 kHz -> 5 * -1 kHz -> 31 * -8 KHz -> 24 increase from 32 to increase resolution Kyle ________________________________ From: james jordan <james.jordan....@hotmail.com> Sent: Monday, November 30, 2020 18:37 To: Kyle A Logue <kyle.a.lo...@aero.org>; discuss-gnuradio@gnu.org <Discuss-gnuradio@gnu.org> Subject: Re: how to auto detect peak frequency in QT FFT sink Hi Kyle, is there any document for how to use the block in gr-fhss-utils especially for fft peak block. what is the two output of fft peak? <http://aka.ms/weboutlook> ________________________________ From: Kyle A Logue <kyle.a.lo...@aero.org> Sent: Friday, November 20, 2020 12:26 AM To: james jordan <james.jordan....@hotmail.com>; discuss-gnuradio@gnu.org <Discuss-gnuradio@gnu.org> Subject: Re: how to auto detect peak frequency in QT FFT sink cmake version is too low so i can not build gr-fhss gr-fhss has a 3.7 and a 3.8 version if you check the tags on github how to store max result to a gui label? qt-number-sink maybe ________________________________ From: james jordan <james.jordan....@hotmail.com> Sent: Wednesday, November 18, 2020 22:07 To: Kyle A Logue <kyle.a.lo...@aero.org>; discuss-gnuradio@gnu.org <Discuss-gnuradio@gnu.org> Subject: Re: how to auto detect peak frequency in QT FFT sink Hi Kyle, Thanks. my cmake version is too low so i can not build gr-fhss. i try to use fft->max but how to store max result to a gui label? <http://aka.ms/weboutlook> ________________________________ From: Kyle A Logue <kyle.a.lo...@aero.org> Sent: Thursday, November 19, 2020 4:05 AM To: james jordan <james.jordan....@hotmail.com>; discuss-gnuradio@gnu.org <Discuss-gnuradio@gnu.org> Subject: Re: how to auto detect peak frequency in QT FFT sink 2 things that come to mind: 1. stream -> fft -> argmax 2. in sandia fhss utilities they have an FFT Peak block that does what you want https://github.com/sandialabs/gr-fhss_utils Kyle Logue Senior Engineering Specialist ⚝ The Aerospace Corporation ________________________________ From: Discuss-gnuradio <discuss-gnuradio-bounces+kyle.a.logue=aero....@gnu.org> on behalf of james jordan <james.jordan....@hotmail.com> Sent: Monday, November 16, 2020 19:09 To: discuss-gnuradio@gnu.org <Discuss-gnuradio@gnu.org> Subject: how to auto detect peak frequency in QT FFT sink Hi all, i want to see the fft of the signal and also want to detect the peak frequency if there is a peak signal. how to achieve this?
