[hpsdr] HPSDR - Penelope update

[pvharman at arach.net.au]

Chris,

Thanks for your feedback and suggestions. My breadboard Mercury receiver does 
have a PWM DAC that I use to drive speakers - its nice to be able to run this 
as a single board without the need to connect to Janus. 

Adding a TLV320AIC23B to provide line out and headphones is certainly something 
we should consider when designing Mercury. 

I now looks like there will be multiple DACs on Penelope for EER requirements 
and using one of these for Rx audio would not be a problem.  We could also 
connect up the Line and  headphone outputs of the current TLV320AIC23B - really 
a matter of what we can physically get on the board.

I did start by having Janus reset the AK5394A but this led to DC offset 
calibration problems which were simple to resolve by doing the reset in Ozy 
FPGA. 

Phil...VK6APH
 






Quoting "Christopher T. Day" <CTDay at lbl.gov>:

> Phil,
> 
> You're probably already planning it this way, but just to be sure the
> idea is out there...
> 
> Looking at Penelope and playing around with the Janus CPLD has got me
> thinking. It looks to me as though Penelope has the hardware, sans DSP,
> for a complete TX chain, i.e., audio ADCs in the on-board TI
> TLV320AIC23B for getting bits from a microphone or line-in onto Atlas
> for the DSP, and the RF DAC to get the bits at "audio" or "if" from
> Atlas to the antenna. How about putting another one of the
> TLV320AIC23Bs, since they are now familiar, onto Mercury so that it is a
> matching full RX chain? I.e., the fast ADC gets the RF down to "audio"
> or "if" and onto Atlas, and the TI takes the processed bits and squirts
> it out the nice headphone amplifier.
> 
> I think this would make for a nice mix-and-match setup. An SWL person
> could get only Mercury and Ozy and have a complete system for his needs.
> An SDR-1000 owner could use Janus and Ozy. A total digital freak could
> go with Mercury, Penelope and Ozy. Surely there is some excuse for a
> Penelope/Ozy only system as well.
> 
> As I say, pretty obvious, but looking at the split of functionality
> between the JanusCPLD and the OzyFPGA, it might be worth thinking about
> moving some items from Ozy to Janus. For example, if the PWM DACs were
> moved from Oxy to Janus and accessed over another I2S, then Ozy would
> hardly notice if that I2S drove the TI chip on Penelope instead.
> Likewise, making Janus responsible for resetting its own AK5394A could
> again make Ozy not care who's on the other end.
> 
> Too late for round one of Janus/Oxy, but maybe worth thinking about for
> firmware upgrades?
> 
> 
> 	Chris - AE6VK
> 
> 
> -----Original Message-----
> From: pvharman at arach.net.au [mailto:pvharman at arach.net.au] 
> Sent: Wednesday, February 07, 2007 7:38 PM
> To: hpsdr at hpsdr.org
> Subject: [hpsdr] HPSDR - Penelope update
> 
> ***** High Performance Software Defined Radio Discussion List *****
> 
> All,
> 
> I've just updated the block diagram of Penelope on the Wiki
> 
> < http://hpsdr.org/wiki/index.php?title=PENELOPE#PENELOPE_-
> _Companion_Transmitter_to_Mercury >
> 
> The latest block diagram reflects the current breadboard prototype. 
> 
> The performance looks very good.  Harmonic content is very low and DDS
> spurs 
> are well below the FCC specifications. 
> 
> Carrier suppression and unwanted sideband suppression also seem
> excellent, at 
> the moment the measurement is  limited by the dynamic range of my
> spectrum 
> analyzer. 
> 
> I've also tested creating AM and FM in the FPGA rather then using the
> 11kHz 
> signal from PowerSDR.  This seems to work fine and eliminates any image
> issues 
> due  to imperfect I & Q  balance. 
> 
> Bill, KD5TFD, has modified PowerSDR to provide the RF envelope and
> carrier 
> phase outputs that will be needed for a future  Envelope Elimination and
> 
> Restoration (EER) power amplifier.  If anyone would like to assist in
> the 
> development of such an amplifier please drop me an email. 
> 
> We are now moving to a prototype PCB which Lyle, KK7P, is designing. 
> 
> There is still a small window to add features so please review the
> latest block 
> diagram and lets us have your ideas and suggestions ASAP. 
> 
> 73's Phil....VK6APH 
> 
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