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* BUGFIX *
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FM step selection problem:
Pot values toggle on some positions between two values, what is normal and no error.
This could be seen on the display if the Step-select-pot is "between" two steps.
The display shows a mixture of both values (flickers).
Therefor the selected step toggles.
I've tried different possible solutions to solve that.
I've used a common method often used in commercial synths/sequencers.
If you change the Step, the Step-value pot is locked.
To unlock it you have to fetch the old value with the Step-value pot.
Turn pot from left to right (or in the other direction).
If the pot-value and the stored value (old value at the selected step)
are the same the Step-value is unlocked and the Step-value-pot
changes now the selected step value.
It is a bit stressy to fetch the old value with the pot to unlock the value but
this has some advantages against other methods, and it is very easy to implement in software.
When the pots get older there could be jumps in the values (like crackling on audio amplifiier pots)
which ignores the "fetch old value"-method.
Since the performance is limited I have to implement all as simple as possible. It's no DualCore Pentium
Another new feature is that the displays shows symbols for the selected synth:
Fraktal1 Fraktal2 FM-Seq WSG
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Here's the bugfix
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICsynth_Betaversion04a.hex