Hi Stefan,
That's very clever. It seems the code is quite complex; can you explain
how it generates a carrier to someone who is an ungifted programmer?
My level is not much better than this:
def beep13(t2):
i=0
while i<500*t2:
i+=1
GPIO.output(13,1) #GPIO.HIGH)
time.sleep(0.001)
GPIO.output(13,0) #GPIO.LOW)
time.sleep(0.001)
return
I used this piece of python as a 500 Hz side tone for a pi keyer but
doubt it will work at 479 kHz.
73 and thanks for the reports on your progress.
Joe
On Tue, 31 Mar 2015, DK7FC wrote:
Hi MF,
Got no answer from PE1NNZ so i spent a bit more time and effort to
'understand' the C-code, i.e. find the correct line where to put a '4*' to
get what i want. I found it (it is: */double freq = 4*centerFreq +
4*((double)(-511 + i))*symOffset/3.0;/* ).
I also compiled it successfully. Now i can externally set the same frequency
(e.g. 475685) but the output and frequency shift is 4x higher. This can be
passed through my /4 CD4013 stage, which is used to generate a perfect
rectangular, opposite phase signal, after the input signal has been distorted
a bit while passing an optocoupler (EMC stuff...).
I know several OMs are using such divide-by-4 stages, which, so far, didn't
allow to transmit WSPR. Now, with the Raspy these days are gone, at least for
me.
If some one is interested, i would of course share the code (you already see
it and just need to find the line in your wspr.c file).
I'm now trying to run a bit more power as usual since the Raspi is directly
connected to the (real) PA:
https://dl.dropboxusercontent.com/u/19882028/MF/Raspi_to_QRO_link.jpg
73, Stefan
PS: Ooooh, of course it could be that someone did the same before me, maybe
even better and so on... so it is maybe not a 'first' whatever!!!!
Am 27.03.2015 14:27, schrieb DK7FC:
[...]And i wrote an email to PE1NNZ and asked to a modification of the
C-program to generate a signal with 4x higher FSK shift. Then it it would
be possible to use that version for OMs having a divide-by-4 stage in their
PA (to get a perfect 50% duty cycle and rectangular shape (after passing
optocouplers etc)).
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