Behringer TD-3 + Arduino – LFO Modulation Testing

Testing LFO Modulation on TD-3 with Arduino.
The arduino code based on my MIDI clock and I added a simple sine wave table output using analogWrite (pwm output). This is just testing out LFO rate / speed locking with tempo (and yes it’s works).

Todo list
• LFO intensity control
• more LFO waveform like square, triangle (sine wave table used in this video)
• Low-pass filter on Arduino output (You can hear some clipping every LFO peak in this video because I don’t used any filter)

Arduino Midi Clock + Effects for Volca Sample & Drum

I added some live effects (PO like) to my DIY arduino midi clock for Volca Sample (Drum works too).

Stutter, Pattern restart, Random trigger, Pitch Up/Down. All effects by midi cc message.

I’ll make git branch from current midi clock code soon.

Volca Sample MIDI Mapper using Arduino

The Korg Volca Sample uses 10 MIDI channels for the each sound. This can not be changed.

This is annoying if you want to use Volca as a external drum machine using a external sequencer or DAW.

This arduino code listen notes from single MIDI channel (16) and send to each channel on Sample (support velocity).

The new code support chromatic play through MIDI channel 1-10.

You need to build MIDI In / Out circuit(or get a MIDI shield). Check out this link for the detail how to build.

Check out other similar project here and here.


Arduino MIDI In & Out Circuit


  • 1 x Arduino
  • 1 x 6N138 Optocoupler
  • 1 x 1N4148 (or 1N914) diode
  • 3 x 220 Ohm resistor
  • 2 x 1K Ohm resistor
  • 2 x 5-Pin DIN MIDI connector (female)

The Code

Note & Update

I’ve change two resistor value in MIDI IN circut.

220 Ohm resistor between optocoupler’s pin 6 & pin 8 to 1K Ohm and 4.7K Ohm between pin 7 & GND to 1K Ohm. It’s eliminate jitters and getting much sharper signals without drop.

And it’s not strictly required but I added a small capacitor between optocoupler’s pin 2 & GND for filtering out high frequency noise.

I think there’re some errors and not optimal part choice in the many MIDI circuit using a 6N138 opto floating around Arduino community. I’ll test with different opto like H11L1 or 6N137 soon.

Added velocity support. Volca Sample don’t listen velocity but support level change with CC msg so it’s now mimicking(?) velocity.

06 Mar 2020 : Now it’s filter out notes from other channels and only listening channel 16 (you can use any note on channel 16 to trigger 1~10 sounds on Sample). All other midi message will not getting through except clock, start, stop and continue(if you don’t need it just comment out from the code).

09 Mar 2020 : More compact code using setThruFilterMode(). Now all message passthru to Sample if it’s from MIDI Channel 16 (VolcaChannel).

12 Mar 2020 : New chromatic notes playing code. You can use MIDI Channel 1-10 for chromatic play each sounds or each note will trigger different sounds on MIDI channel 16.

Arduino Midi Master Clock

DIY Arduino MIDI master clock/sync/divider for MIDI instruments, Pocket Operators and Korg Volca.

You can easily find similar projects but I added ability to sync different PPQN via 2nd 3.5mm trs jack (check-out demo video below).

MIDI & 1st audio jack sync according to BPM and I can adjust different PPQN with encoder (push once) for 2nd audio sync jack.

Continue reading “Arduino Midi Master Clock”