Koellner, Guenter schrieb:
>Hello Tobias,
>
>just a question, maybe I am simply missing something from the user manual: How
>do you change Winrad L.O. frequency by, e.g. 25kHz. I only found the method of
>tuning with the mouse wheel, while havign the mouse pointer above the digits
>of the L.O. display. So one can change by 10kHz, but this will be rounded down
>and so no actual change will happen. Maybe I have missed some possibility.
>
>73, Günter
>
>
Hallo Günter !
Hallo Alberto !
It's much more easier than I thought of : To calculate the "new" LO
frequency, we use the "integer division" method and an additive term for
frequencies just above the old LO. Pseudocode :
The variables, all frequencies in Hz :
old_LO : the frequency the VFO is currently at.
new_LO : the frequency where any user input wants us to move to.
stepwidth : the VFO is capable of generating frequencies this step apart.
first we decide if we have to do some correction for later algorithms :
if (the new_LO is higher than old_LO) and ( new_LO is less higher
than one stepwidth), then
we add just one stepwidth to the new_LO.
Second step is to use the "integer division" to get a frequency at any
VFO-step :
(Declaration of "integer division" : after division the remainder is
discarded, the output is an integer )
new_LO is equal to : (new_LO divided by stepwidth) multiplied by
stepwidth.
Thats all.
At any frequency change below one stepwidth the new LO is moved away at
least to the next stepwidth-dividable frequency. At higher frequency
changes the new_LO is moved directly to the exact frequency or -at
least- to the nearest lower frequency available.
73 de dg3lv Tobias
A dummy DLL (without managing the hardware) is already running under
WinRad 124b30.
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