[hpsdr] [JANUS] Offloading SDR-1000 reguired I/O from OZY

[Philip Covington]

On 5/11/06, pvharman at arach.net.au <pvharman at arach.net.au> wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> Hi Alex,
>
> I'm not sure how fast the Parallel port to SDR1000 hardware interface needs to
> be but one idea I had was to use a 16 bit I2C port expander to do the
> interface. I have one hanging off my Janus breadboard, controlled over the
> USB/Xylo interface,  that I use for slow I/O like band switching, it works
> fine. I guess the DDS  needs the fastest update rate but I'm not sure what
> speed you can actually get from a parallel port under XP.
>
> Whilst adding another dedicated I/O board to meet the needs of bulk switching
> (a la UCB) is a good idea, all I really want is  PTT, dot and  dash  inputs
> and an open collector output to control my linear. With those lines I have a
> radio with a few boards in the Atlas bus that I can actually use and it puts
> off the need for a bus expander for a while. If I do want complex or more I/O
> features then I can add the fully featured I/O board later on.
>
> 73's Phil...VK6APH

If there is room on the OZY, what if I add a port expander (I2C or SPI
or ?) to the board and provide 8 buffered ins and 8 open collector
outs?  That way I can avoid using up all the extra  I/O but still
provide some protected IO on the OZY for purposes where a separate IO
board is overkill?  I will look at that tomorrow...

73 de Phil N8VB

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