Tap tempo dead zone and lower limit

[bakarasche]

Hi. Builty.
Thank you for implementing tap tempo.

I immediately assigned tap tempo to a wired foot switch and tried it out.
(My AtomS3R firmware is a modified version of discussion #113.)

I think tap tempo works properly.
Amazing!

According to control.c,
the current lower limit and dead zone of BPM are
Lower limit : 60
Dead zone : +/-25

But I prefer
Lower limit : 40
No dead zone

I think the lower limit of 60 is set to the maximum value of Delay time, 1000ms. However, since BMP is also used to set the rate of the modulation effect, I want to set it to 40 to match the lower limit of BPM of MIDI CC.

Also, if the dead zone range is wide, it is difficult to set the tempo precisely,
so I think it is better to set the dead zone range to 0 or smaller.

However, I think that different people have their own preferred settings.
Therefore, I propose adding settings for the tap tempo lower limit (and upper limit as well) and dead zone to the web settings GUI.

[Builty]

Hi. Thanks for the report. The 60 bpm value is actually a mistake. I thought that was the pedal limit, but no its 40 as you say.
The dead zone part was intended to avoid sending excess messages to the pedal, but thinking about it, I tend to agree now its not needed.

I've removed the dead spot and fixed the lower limit value now in the latest commit.