[hpsdr] ANAN-100D Angelia_test_v3.9 code

[Joe Martin K5SO]

Yes, it’ll be a learning experience for me to be sure.   May take me a while, hihi, but I’ll let you know what I discover.

73,  Joe K5SO

On Feb 9, 2014, at 3:20 PM, Brian Lloyd wrote:

> On Sun, Feb 9, 2014 at 3:41 PM, Joe Martin K5SO <k5so at valornet.com> wrote:
> Hi Brian, 
> 
> You’re not asking for much, are ya!  From what I can see it would involve a complete disassembly of the ANAN-100D in order to gain access to the relays themselves on the PA board, and I’ve had the thing for less than a day, hihi.  
> 
> Yeah, sure, I’ll look it over and see how much trouble I can get into doing it to check out the possibility for you; if you’re sure you don’t want to dissassemble yours instead, that is!!  
> 
> Well remember, you don't own it until you take it apart! I make a point of dismantling nearly everything I get new. My ANAN-x radios were no exception. I am quite comfortable with my ANAN-10 and ANAN-100D in pieces on the bench. (I have made board-level SMD changes on the Hermes board in my ANAN-10 to fix the external 10MHz reference input. I don't have a hot-air rework station for nothin'!)
> 
> But in this case the only disassembly required would be for the code going into the FPGA. The chips that drive the relays in the ANAN-100D PA BPF (turns out they are bandpass filters, not lowpass filters) are a pair of cascaded TPIC6B595 8-bit, serial-in, parallel-out shift registers with high-power open-drain outputs. The way you select a filter (or an antenna) is to put a one on the SPI_SPL_DATA bus at the input and then clock the shift register until the one appears at the appropriate point in the shift register and pulls that output low to activate the correct pair of relays to select the desired BPF. (Actually, you use that to select a number of things including antenna relay, the bypass relay, and the bandpass filters so it would be normal to clock more than one '1' bit into the shift register.) But if somehow you clocked in TWO one bits and shifted them into the BPF0-BPF5 outputs you would end up with TWO BPFs selected. The interesting thing about this bug is that the PA would still work but you would probably get strange gain changes at different frequencies due to the paralleled bandpass filters. And this is something that is a software/firmware problem rather than a hardware issue. SPI_SPL_CLK and SPI_SPL_DATA both come in from the Angelia on the 10-pin ALEX umbilical. Just look at the schematic for the ANAN-100[D] PA board to see what I am talking about.
> 
> Hmm, this is where a bunch of little LEDs showing the status of these open-drain lines would be nice. Better still, bring them out to the front panel of the ANAN-100D so we have something to look at. :-) But I digress ...
> 

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