[hpsdr] Operating Configurations

[Christopher T. Day]

[Bloodied, but still unbowed.]

Ok, this is getting really close. 128 bytes is still small, but getting
there, and the programmability and price are right.

What's probably my last gasp argument for larger EEPROM - Having only a
hardware ID forces us to have an Ozy specific first driver to make the
cross references off-Ozy and load the descriptors for the ReEnumeration
of the Atlas devices. One of my hopes - pretty feeble now - is that we
could get away with using generic USB drivers as much as possible. Those
could be driven off the full Device Descriptors if the FX2 could present
them on the first enumeration. With the small EEPROMs, the first
enumeration has to be handled by an FX2 driver that can sort out the
ID/Device Descriptor connections, call Vendor Loads to get the Device
Descriptors into the FX2 and then trigger a ReEnumeration. The second
pass still has some potential for generic drivers.

Oh, well, unless someone can find a decent sized 1-Wire EEPROM, I guess
we go with the second scenario. I'm presuming for the stand-alone SDR
fans, Ozy isn't used in the field anyway.


	Chris - AE6VK


-----Original Message-----
From: Lyle Johnson [mailto:kk7p at wavecable.com] 
Sent: Friday, May 12, 2006 11:23 AM
To: Christopher T. Day
Cc: Alex; Philip Covington; hpsdr at hpsdr.org
Subject: Re: [hpsdr] Operating Configurations

Hello Chris!

> ...1-Wire sounds even better in principle; I
> just can't make the available parts I know about - and I know very
> little about them - fit the problem. For instance, my brief scan of
the
> EEPROM data sheet indicated that the "Erasable" part of that is very
> weak; essentially these are Once Programmable devices. For
developer's,
> turning the typical cycle into Code, Compile, Load, Debug, Heat Up
> Soldering Iron, Replace Part and Repeat, doesn't sound very appealing.
> Nevermind expensive.

DS2431P has 1 k-bit of EEPROM, can be erased/programmed 200,000 times, 
retention is 10 years minimum, and costs 61 cents in 1K qty ($1.15 in 
unit qty).  And has a 64-bit serial number unique to each device.

73,

Lyle KK7P



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