Jim Great post! Let the software folks totally exhaust themselves BEFORE we look for a hardware 'assist' to the current model. (FPGA not withstanding.)
I am "Case in point", since I sent a LOT of, well thought out 'daughter cards' at my expense to solve a "latency" problem generated by a hardware shortcoming on the SDR-1000. Many folks modified their hardware at my initiative, (but not design). I don't apologize for mentoring. It is the price of experimentation! The design DID solve the hardware problem and after that: "It was solved in software"! (and found to be a limitation of a particular soundcard). LO! I take the blame for that, and many users had to modify their SDR-1000 boards back to original! I apologize, but should listen to you and the software developers! I am following your questions on documentation of the code, and enjoying it. Thanks for being here! Eric -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jim Lux Sent: Tuesday, February 28, 2006 10:46 PM To: Bob McGwier N4HY; Mark Ericksen Cc: FlexRadio@flex-radio.biz Subject: Re: [Flexradio] Question About VOX and Other Stuff At 10:14 AM 2/28/2006, Bob McGwier N4HY wrote: >It can be implemented in hardware and it should be along with the proper >keyer and sidetone where they both belong. I respectfully disagree. Isn't the whole point of a software radio with a minimalist hardware to do as much as possible in software. The SDR1000 itself is essentially a zero delay system.. all it does is translate I/Q baseband to/from some useful RF frequency. So the challenge is in doing these functions in software, or, more to the point, trying to do what is a fairly "hard real time" kind of application in a "non hard-real time" environment (e.g. Windows). An existence proof that it can be done is provided by such things as games, which have to respond to game controller/keyboard inputs in millisecond type response times. It may well be that the system architecture that's evolved for the SDR1000 software inherently cannot do this sort of thing, but that certainly doesn't mean that it can't be done, or shouldn't be attempted. Perhaps there are things that the current approach cannot and will not ever do, but that's just fine, as long as it does a good job of the things that it CAN do. In fact, this is one of the beauties of the SDR1000, it literally is limited only by the inventiveness of the software developers. Sure, it might require writing Windows I/O device drivers to meet the real time constraints, but that's a problem that's been faced by lots of people developing software for the PC platform before. It might suck up an amazing amount of processor resources (because you have to poll some I/O line for reading the key), but maybe that points towards using a dedicated PC for those sorts of uses. With diskless PC mobos being in the <$100 range, that's starting to be competitive with the cost of a fancy keyer for a conventional rig. I have always thought that the optimum solution is one where the non-real time UI is on some normal user style computer, but that the hard real-time processing is on a PC dedicated to the radio. The convenience and consumer price points of the PC platform for the DSP is just too attractive to pass up, compared to some hybrid scheme (e.g. using a DSP Eval board or something for the DSP). Jim, W6RMK _______________________________________________ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
