Pete, I would like to see a basic "break-out" Si570/571 board similar to the one available from WB6DHW that has a couple of added things:
1. An LVDS level translator that can be optionally populated on the board or jumpered-out. Which translator is a question, the Fairchild FIN1002 might be a good choice, but one has to question whether this is optimal for LVTTL interfacing with faster 74ACXX-like devices. 2. An I2C interface that is high-speed opto-isolated to the Si570, not just a level translator that has a common ground. This would go a long way to removing ground loops when controlling the Si570 with any other device (uC, another PC etc.) Can't suggest a part, just started looking. Now that's just my opinion of physical layer + I2C link layer interfacing. If you want to add a part that has a standardized command set, if you will to control the Si570, that will require a debate beyond my knowledge. A good place to start would to canvass the available direct-conversion SDR software applications to see what interface type is most popular, like CAT or something similar. Ideally, whatever sequential-state-machine that does this (arguably, link-layer or app-layer) interface should accept a frequency string down to tenths of Hz at least and calculate and program the Si570, and do it fast. This will involve either floating point support of at-least assembler floating point emulation to 32 bits (I'm just starting to look at this). This 'intelligent' part that can handle Si570 frequency programming 'on-the-fly' may be relatively expensive compared to a part that simply stores a pre-programmed table of frequencies. For a pre-programmed part with tables (arrays if-you-will) then you get into how to program the parts in the field, for support of IARU Region-1, 2, 3 etc. not to mention different step sizes for general-coverage. just throwing this reply out. Type-as-I-think real-time. 73's David --- In [email protected], Pete Smith <[EMAIL PROTECTED]> wrote: > > At the risk of getting ahead of the curve, I wonder if anyone is thinking > about a next-generation Xtall board that would provide a standard interface > to various control programs that might want to set the Si570's center > frequencies. What might such a standard look like, and what would be > required to implement it? > > 73, Pete N4ZR >
