TAPRECISE - Calibrated Tap Tempo with Presets, Subdivision and Modulation

[Marshall Arts]

This is "Taprecise", an Arduino-based tap tempo control for PT 2399 based delays, that can be automatically calibrated to compensate any tolerance in the required digital pots (up to +/-30%). Calibration takes 2-3 minutes and only needs to be done once. After that, you get "what you tap is what you get". Features:

• Absolut precise tap-tempo control
• Rotary encoders for delay time fine tuning, modulation depth and speed
• Footswitches for tap tempo, preset, subdivision
• Mini switche for modulation on/off
• Subdivision for 1/8, dotted 8th, 1/3 triplets
• Two user-definable presets (can be stored in standalone mode, of course)
• Connection to Delay requires a simple stereo jack, which also powers the tap-tempo-unit
• Open source code to adjust code to user preferences (uploadable via accessible USB-Port on enclosure side)
• Fits in a 1590B

I assume, that this can be used for dual PT2399-Delays as well (see discussion here: http://www.madbeanpedals.com/forum/index.php?topic=22253.msg222337#msg222337), but this still needs to be tested (by someone, who has a dual PT2399 delay ). Once I have put my delay (a deep blue delay) and Taprecise in two 1590Bs, I will offer this as a group buy (and also release latest documentation and updated code).

Developing taprecise took more than half a year with a lot of discussions with many users here - thank you for your input. I cancelled some features I had foreseen in the past (e.g. "strum tempo", which worked, but required too many components/space) and added some (e.g. the "preset" feature).

Group buy link: http://www.madbeanpedals.com/forum/index.php?topic=22682.0

Here are some preview images:

[monkeyssj1]

so rad!!!!!!!!

[selfdestroyer]

This came together nicely. Great job man. I will definitely get in on a group buy.

Cody

[matmosphere]

Very cool, I'll probably get in on the gb as well.

[Martan]

Awesome job!

[Leevibe]

Right on! You are the MAN for sticking with this circuit. That's looking a fair bit tidier than the breadboard! Haha.

[micromegas]

This is a really cool project! Lots of possibilities. Sign me up for one!

[Martan]

Any idea if this could be integrated into a larger controller like the one developing at TH_Customs? Coordinate presets and what not?

[Marshall Arts]

It's a microcontroller, so adding an interface would be possible. But: other layout, more storage for presets etc required .... So basically: take the source code and build it ( and share alike )

[Orbis_Ignis]

I've never played with anything like that. It looks awesome. I'd definitely be interested

[Marshall Arts]

Right on! You are the MAN for sticking with this circuit. That's looking a fair bit tidier than the breadboard! Haha.

Thanks so much :-)! I already have plans for an even more nerdy thing: A universal pot that can emulate pots from 5k through 500k, any taper (Lin, log, rev log, ICAR) and can be controlled with any pot/foot rocker. Think of a pedalboard with just one expression pedal that controls either way, volume or vibe...

[nmbb]

This came together nicely. Great job man. I will definitely get in on a group buy.

Cody

Same here!

[drolo]

That looks great, and this even more :

Thanks so much :-)! I already have plans for an even more nerdy thing: A universal pot that can emulate pots from 5k through 500k, any taper (Lin, log, rev log, ICAR) and can be controlled with any pot/foot rocker. Think of a pedalboard with just one expression pedal that controls either way, volume or vibe...

Make sure to let us know if you pull this off :-)

[Thomas_H]

Right on! You are the MAN for sticking with this circuit. That's looking a fair bit tidier than the breadboard! Haha.

Thanks so much :-)! I already have plans for an even more nerdy thing: A universal pot that can emulate pots from 5k through 500k, any taper (Lin, log, rev log, ICAR) and can be controlled with any pot/foot rocker. Think of a pedalboard with just one expression pedal that controls either way, volume or vibe...

Let me know what you find out - I looked into it and I dont think it is possible. (Using a single digital pot)

[Marshall Arts]

Let me know what you find out - I looked into it and I dont think it is possible. (Using a single digital pot)

I would not use a digital pot (due to noise when changed), but rather use two Vacontrols or LED/LDR combination and (LPF'd) PWM from the arduino side. I would calibrate the microprocessor to both, the used foot control pot for input (measure 10 points or so directly from the arduino) and the output (resistance depending at given PWM). My biggest concern is, that the LDR's don't go to zero resistance and are higly non-linear.

For Volume Control, I would probably put the LDR in the feedback loop of an opamp (so it does not have to go down to 0 Ohm) to achieve unity gain. For Wah use, I am not concerned that much, as it seems to work well in Morley Wahs. This would likely be true for other use cases (Univibe etc.) as well.