Not sure if this would be helpful but if you are looking for something=20 to generate audio signals, try different filters etc. you could take a=20 look at Pure Data https://puredata.info/ Jim On 2019-01-14 7:33 a.m., David Van Horn wrote: > Is there a package available that will let me experiment with various DSP= functions on the PC platform while I search for a microcontroller implemen= tation that fits my needs? > Ideally I would be able to create files (WAV?) with noise sources, signal= sources, impulse noise etc mixing them into a file and controlling their a= mplitudes individually, even listening to it to compare to what I hear on a= ir, then feeding them to the algorithms, showing waterfalls.. > > I really would prefer to get this in a single package, or maybe two parts= , so I can concentrate on solving the problem. > > -----Original Message----- > From: piclist-bounces@mit.edu On Behalf Of Davi= d Van Horn > Sent: Thursday, January 10, 2019 8:52 AM > To: Microcontroller discussion list - Public. > Subject: RE: [EE] DSP algorithms for very narrow band applications > > I've been interested in the 630 meter band between 472 and 479 kHz for so= me time, I would like to see just how good a receiver I can make. > 5W EIRP maximum, and contacts are already being made over huge distances. > > > -----Original Message----- > From: piclist-bounces@mit.edu On Behalf Of Haro= ld Hallikainen > Sent: Wednesday, January 9, 2019 2:38 PM > To: Microcontroller discussion list - Public. > Subject: Re: [EE] DSP algorithms for very narrow band applications > > Sounds like an interesting project! I have very little DSP experience oth= er than telling a DSP engineer what I want, and the code magically appears.= But http://www.earlevel.com/main/2013/10/13/biquad-calculator-v2/ > has proved useful. I'm currently using a biquad as a CW filter for recept= ion by ear. Picking up signals below the noise level is interesting. > This, of course, is what FT8 and similar weak signal techniques do using = multi-frequency shift keying. > > Are you also looking at machine decoding of the CW? I note that there is = a CW decoder in KiwiSDR, but it is very error prone with noise and fading. > > I am, as a background project, looking at using SOMETHING for amateur rad= io applications. My transceiver has an RS485 control bus along with a balan= ced audio bus and PTT. I'm thinking of maybe using an old netbook to contro= l it, stream audio, etc., OR using a PIC32 (maybe MZ) to do the same. I'm M= UCH more familiar with PIC32 software, including streaming audio (PCM and A= DPCM) than I am familiar with linux talking to hardware like a USB audio in= terface, USB RS485 interface, etc.). So, still playing around with ideas. > > I look forward to hearing other comments you get. > > Harold > http://w6iwi.org > >> I had posted a couple weeks ago and I guess it fell in the bit bucket. >> >> I'm looking for info on DFT or similar approaches to detect very weak >> CW signals buried in noise. >> I'm only interested in a 200Hz window, and I can control where it >> falls frequency wise, between 150Hz (center) and several kHz. >> I need as much frequency detail as possible, sub 1Hz definitely, but >> the "dot" is pretty short. At 20WPM that works out to well below. >> https://www.w8ji.com/cw_bandwidth_described.htm >> >> This will get implemented on an AVR or similar, with input from the >> on-board ADC. >> >> I expect I will need a rather long array of samples, but I am starting >> to think of a circular buffer there and sending chunks of to the DSP pro= cess. >> >> I have looked in Smith's DSP book, but I haven't found what I'm >> looking for. >> >> -- >> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> > > -- > FCC Rules Updated Daily at http://www.hallikainen.com Not sent from an iP= hone. > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/cha= nge your membership options at http://mailman.mit.edu/mailman/listinfo/picl= ist > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/cha= nge your membership options at http://mailman.mit.edu/mailman/listinfo/picl= ist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .