[hpsdr] User Open Collector Outputs on J16....

[Rob Frohne]

Hi All,

I'm wondering if anything has started to set the standard for what the 
user open collector outputs on J16 are going to be used for?  I would 
like to make my use as compatible as possible with other's use.  I am 
looking into interfacing my Hermes with an old FT-847 that was hit by 
lightning, and the signals I'm considering putting on these pins are:

HF RX
HF TX
VHF RX
VHF TX
UHF RX
UHF TX

I need these to control 8 V power supply signals that correspond to 
those signals.  All six are likely necessary for proper T/R sequencing.

There are also three outputs that are presently used only for debug LEDs 
1-3 that are available on J14.  Should I consider using these?

Also, the FT-847 uses analog voltages also used in the PLL VCO circuits 
to tune some varicap diodes in the filters.  I may be able to get by 
with a fixed voltage there, but it made me wish for some analog outputs 
from Hermes other than the audio.  It is interesting to note that rigs 
like the FT-857D use those to make aligning the radio an all digital 
thing.  The microprocessor sets analog D/A signals that are used to set 
bias on the PA units, etc.  You don't have to get your screwdriver out 
at all, you just adjust everything from the front panel!  It seems 
possible to hook up a serial D/A that would do that kind of thing, but 
how much room would that take in the FPGA?  Is there enough left?  It 
seemed pretty full last time I looked.

Any advice on any of these choices?

73,

Rob
KL7NA