[hpsdr] Pre-Selector alternative for Mercury - How to controll viaHPSDR/PowerSDR

[Bill Tracey]

Interesting architectural question - where is the better control 
integration point for the hardware piece parts in our SDR - out in 
the radio hardware or back at the PC.  For something like this I'd 
argue for the PC in that I suspect it is easier for most folks to 
modify PC based code than firmware and doing it at the PC makes the 
hardware applicable to more radios than our radio.  I've always 
wondered a bit on why the SDR 1000 did the open collector outputs and 
the Flex 5k has flex-wire when you could just control ancillary 
devices by connecting back to the PC and let the radio software handle it.

I don't discount Alberto's observation if it is done in the hardware 
it works for the different software packages .  More raising the 
(somewhat philosophical) question of where the right place for  this 
type of integration is?   In my mind I think the design is more 
flexible if the devices that  can be PC controlled are,  For example, 
one could have done Alex with a USB controller and instead of having 
a dedicated connector coming off Mercury you'd run USB back to the PC 
to control filter and antenna selection.  Would likely raise the cost 
of Alex a little but would make it applicable to projects other than 
HPSDR.

Cheers,

Bill (kd5tfd)

At 08:56 AM 3/29/2009, Alberto I2PHD wrote:
>***** High Performance Software Defined Radio Discussion List *****
>
>
>Phil Harman wrote:
>>
>>Well there are a number of options as to how the Heros board could be used:
>>
>>1. Add support to PowerSDR for it's USB port
>>
>IMHO, this option is not the optimal one, as it will tie the use of 
>the preamplifier to the use of PowerSDR.
>Should one day a new program supporting HPSDR come out, you won't be 
>anymore able to use the Heros board.
>>
>>3. Replace the USB board with one fitted with an SPI or I2C open
>>drain/collector driver chip(s) and send the required signals from Ozy or
>>Mercury. This is basically how the relays on Alex are switched.
>>
>Again IMHO this is preferable, provided that the commands needed for 
>that, embedded in the outbound USB
>stream to Ozy, are clearly documented.
>
>Just my opinion
>
>73  Alberto  I2PHD



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