Analogue-sequencer

> > Maybe the current tempo map could do with some tweaking though.
> > What tempo ranges do people use ?

> lowest i would ever use would be around 130, highest about 200.
> grtz Chiel

So the general consensus seems to be  - we all use different tempos !

Anyway... in the firmware version I'm working on, I've ripped out the
lookup tables for the 16 bit timer values for each tempo, and replaced
it with a routine to calculate the timer value from the tempo value
directly. The divide routine uses the same ROM space as the lookup
tables, so the code size is the same.
The tempo value is now held as the 'real' number i.e. the tempo in BPM.
Before it was held as an index to the lookup tables.
There is still a lookup table to hold the real tempo value for each
position on the tempo pot, since the tempo pot only has 128 positions.
I have spread the map out a bit - it now runs from 30 to 253 BPM. 30 is
the minimum possible with the timer, 253 just happened to be where I got
to with the new spacing. The maximum that could be held in the tempo
variable is 255 anyway.
The extra resolution will be provided by the fact the the tempo value is
multiplied by 10 before it is passed to the 'calculate timer' routine.
So I can easily add a 'fine tempo adjust' variable that will be added to
the 10x integer tempo value when the clock period is calculated - giving
the fine tune value a resolution of 0.1 BPM.
The question now is how to make this value accessible through the UI. I
was thinking of making FUNC+data adjust the tempo fine tune over a range
of 0 to 5 BPM, in 0.1 BPM steps, very much like the fine tempo control
on a TR808.
This will fill in the 'gaps' between the integer tempo values for those
of you who need to fine tune to the tempo to an audio sample, but can be
ignored by the rest who are happy with tempo adjustment in 1 BPM steps
(or 2 and 4 BPM steps as you approach the limits).

Cheers,
Colin f