[hpsdr] Penelope Troubleshooting

[David McQuate]

The fact that LED7 changes blink rate--to indicate PTT change--shows 
that the FPGA is at least partially alive and working properly.  If 
Bob's software / firmware suggestions don't take care of the problem, 
and you have an oscilloscope, you might carefully probe the DAC input 
data lines while TUN is active: bits 0 - 13 on U7 pins 14 - 1.  The 
lower bits should have high frequency square waves, the higher bits, 
lower frequency.  These are the digitized sine wave generated by 
PowerSDR to produce the CW TUNE signal.  The clock input, U7 pin 28 
should have a very fast square wave -- 8 ns period.  If they're 
changing, but there's no signal on JP3 pin 2, there's a problem with the 
DAC.   Check that pins 24, 25 & pin 27 are +3.3 volts.

With TUN active, Atlas C19 should have digital signals--the transmit 
data--I & Q data from the PC via Ozy.  The data is sent using "NWire", a 
digital pulse-width modulation, with a "0" represented by a short high 
pulse, and a "1" by a longer high pulse.  Thus when sending all zeros -- 
as when PTT or TUNE are not active -- there will still be many fast 
pulses, in bursts with a 48 kHz repetition rate.

Atlas C20 should also have digital sgnals -- the command and control 
data broadcast by Ozy to Mercury & Penelope.

73,
Dave
WA8YWQ

On 7/28/2012 1:39 PM, Stephen West-Fisher wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> It didn't take very long for me to exceed my troubleshooting skills so it's
> time to ask for help.
> This is a Penelope that I populated (the source of the problem).
>
> I had no errors loading the code through Ozy.
> On power up I have LED1 solid and LED7 on slow blink.
> When I push the TUN button LED7 changes to a faster blink. My understanding
> is that everything is correct to this point.
>
> I get 0 output. PowerSDR also shows 0 output with drive at 100. PA is all
> set to 38.8. Tuned to 7.2.
> I also have 0 volts on pins 1&  2 of both JP 2&  3.
> I do not see any solder bridges but I know that is no guarantee, what else
> can I check to find the source of no output?
> Thanks!
> --
> Stephen West-Fisher
> N4IK
>
>
>
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