Working on a sequence tremolo

[3080]

Very nice! I like how you placed the LED's. It looks a bit complicated to set up though, with only two knobs. You could of course use two SIPO shift registers to set the led's and that would only cost you tree i/o lines. It does require some extra ic's.

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- Pressing the right knob inverts the waveform, not very useful.

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Tap-tempo instead?

BTW.. brilliant design!!!

[Galego]

Real nice work.  I've had a similar idea on the drawing board for a long time but haven't gotten around to it.

What I am very impressed with is the digital noise reduction work.  It sounds very very quiet.

The big question I have is about your Ground to Digital Ground connection.  The dsPIC datasheets recommend a 10 ohm resistor between the analog and digital grounds (which are separate on those chips), but you are using 100 ohm to all grounds.  It seems to me that would starve the chip of current (allowing a max of 50mA).  Did you consider this?

Also, do the opposing 1N914 diodes make a difference in noise?

I've never seen a resistor going into a voltage regulator (I've only seen them on the output side of a V/R to provide a constant current) - is that your own idea?   Are those for noise protection as well or for current regulation?

I mostly use the dsPIC's but I'm hoping that your cap-happy techniques will help quiet down some of my projects.

As far as comments - I can tell you from experience that it takes a ton of troubleshooting to make encoders work fluidly, and even using the same brand of encoders with different numbers of detents will require a lot of re-writing of code.  I don't think there is any shortcut, but I would put more effort into tweaking your encoder code so they react more naturally.  A big part of the job is sorting out your interrupt priorities - which will be different on every project.  I didn't review your code, but from your video it looks like you have your encoder too low.  I assume with the 18F you can turn on and off nested interrupts.  You might want to look into that as well, because it looks like you are missing some encoder interrupts.

Thanks very much for sharing!

Thanks

Yes, all that was to quiet down the circuit. I don't really know the logic behind what i did other than "i saw it somewhere, tried it and the circuit got quieter".  
I tried small value resistors on the GND connection and before the regulators until i could find something usable and that removed most of the noise, the 1N914 thing i saw in some site, being used to separate the digital and analog grounds.

Without these changes i could always hear the blinking leds popping on the audio output. There's still some popping but just on ramp down mode, but i think that's just because of the sudden and drastic change of the resistance of the LDR as it doesn't happen in other modes and it only happens in the tremolo version, probably could be solved by having some smoothing to the ramp start.

Some of the values i tried before did cause brow-outs, but this has been running really smooth for a while, on both pedals. The only thing that is still a bit crappy is that all the leds being lit in one of the controls do affect the led that's in front of the LDR (or in a vactrol in this case), so sometimes when you change mode, you can hear a drop in volume in the tremolo pedal.

The encoders run just fine, and i don't use interrupts for them, their processing is entirely done in the main section of the code. The only interrupt i use is the Timer2 and that's for the PWM calculations. As long as you don't try to spin them super fast they are very responsive and precise.

[Galego]

Tap-tempo instead?

BTW.. brilliant design!!!

Thanks

Tap tempo could be an option, for a larger enclosure. I would need to rethink the interface as i have no more input pins left on this chip.
Or do you mean tap tempo by pressing on the knob for that function?

[3080]

Tap-tempo instead?

BTW.. brilliant design!!!

Thanks

Tap tempo could be an option, for a larger enclosure. I would need to rethink the interface as i have no more input pins left on this chip.
Or do you mean tap tempo by pressing on the knob for that function?

Yes! By pressing the knob.

[Galego]

I can do that... 

[cloudscapes]

this thread has inspired me to redesign/rewrite my waveshaper device. which was badly needed!

[Galego]

this thread has inspired me to redesign/rewrite my waveshaper device. which was badly needed!

Funny how that works. Your waveshaper gave me ideas/inspiration, and you get some from what i did. 

Can't wait to see what you come up with.

[Barcode80]

this thread has inspired me to redesign/rewrite my waveshaper device. which was badly needed!

Funny how that works. Your waveshaper gave me ideas/inspiration, and you get some from what i did. 

Can't wait to see what you come up with.

Any chance of a project for this?

[Galego]

this thread has inspired me to redesign/rewrite my waveshaper device. which was badly needed!

Funny how that works. Your waveshaper gave me ideas/inspiration, and you get some from what i did. 

Can't wait to see what you come up with.

Any chance of a project for this?

This thread is a bit old, maybe you should PM him...

[soggybag]

Great work, very inspiring. I made a random Wah with a AVR. I used the same Colorsound wah. Mine only has a speed control so it's much simpler.

[crane]

To the author - really nice and well finished project.
May be some of you would be interested into one of my projects as well.
I made a Meatball for friend of mine and he wanted something like Ooh wah as well. I decided to bring it to the next level - add a CV input to the Meatball and create a 16 step CV generating sequencer.
Some of the features:

x) powered by ATMEGA16 (if I remember correctly )
x)16 steps - each controlled by a potentiometer
x)speed control pot
x)step count control pot
x)tap tempo and reset switches on additional footswith
x)MIDI control

Here are three videos to explain all my talking (I'm sorry for the videos being not very musical)
Here's the first version with 8 steps, no MIDI, no footswitch

Here's the second one with 16 step sequencer

Here's the last one with real guitar signal in input

I know that the device isn't very easy to operate as you can adjust the voltage of each step really fast - just rotate the correct potentiometer.
The other great thing about this device is that it can be used with any effect accepting control voltage. I have created a tremolo with CV in and I'm working on a vibrato for the same friend.
Hope that this was interesting for someone

[nordicskiah]

I would love to see an update on this project! Did you integrate in the 8x8 LED matrix? Any changes in the schematic you posted?