I do not intend to include anything in the DDS PIC firmware other than
an ability to translate ASCII commnads into control words, and
optionally store the settings to EEPROM for instant return to the same
CW frequency. This approach will make for a general purpose standalone
DDS generator module. Any frequency modulation - or phase change - will
be made in real time by a PC sending serial commands to the DDS.
While it would have been possible to dispense with the PIC altogether
and drive the AD9850 directly, it is more robust, and certainly easier
to write high level software, if a standard serial RS232 type protocol
is used. WINDOZE programming makes it more difficult to address PC
I/O ports directly than was DOS.
Dave 'MRF, when you say linear BPSK what do you mean ? There is no
option to shape the waveform surely with only 0 / 180 and no signal
states.
Andy G4JNT
----------
From: [email protected][SMTP:[email protected]]
Reply To: [email protected]
Sent: 2000-05-09 14:32
To: [email protected]
Subject: Re: LF: DFCW Parameters
Thanks to the reflector and a lot of hard work by Johan SM6LKM - DFCW
has
now been included in the PIC16F84 firmware used in the 9832 DDS. + or
-
Offset can be changed.
Linear BPSK has also been included in hardware. Unfortunately, no
computer
transmit / receive programs have been found yet which can take
advantage of
the new BPSK feature. ( 0V = one phase, 12V = -180 degrees 6V = no
output)
But I'm still looking. Any ideas anyone?
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