Oscillator

miniMO's Oscillator is a general purpose Digitally Controlled Oscillator (DCO), with several available waveforms and simultaneous frequency and amplitude modulation from external sources.

SOURCE CODE

Download from Github

FEATURES

  • Waveforms: sine, triangle, square, saw
  • Real time wave switching
  • Frequency range from 1Hz (LFO) to 1.5 KHz (higher values are possible)
  • Real time frequency range switching
  • Real time frequency and volume control
  • Real time frequency and amplitude (volume) modulation
  • Automatic Calibration Mode
  • Automatic Battery check

MANUAL

I/O

  • 1&2: Outputs - waveform
  • 3: Input - frequency modulation
  • 4: Input - amplitude modulation

MODES OF OPERATION

PLAY (default)

  • Knob: change frequency (default) or amplitude
    • When you change between modifying frequency and amplitude, miniMO memorizes the point where you leave the knob
    • When you start modifying a parameter again, miniMO waits until you reach the value where you left it earlier
  • Single click: cycle through the available waves, from less to more harmonics
    • After the saw wave there is a "silent wave" that mutes the output (stored volume remains unaffected)
    • After a single click, the LED blinks once
  • Double click: cycle through the frequency ranges
    • After a double click, the LED blinks twice
  • Triple click: go to frequency calibration mode (see below)
  • Click and hold: modify the amplitude using the knob
    • While holding, the LED blinks constantly

FREQUENCY CALIBRATION

When you enter this mode, miniMO starts an automatic procedure and maps its frequency inputs to the expected ranges

  • If you are connecting a miniMO sequencer or tuned controller:
    • Move the knob all the way down (counter-clockwise)
    • Set the frequency range to the middle
    • Click the button three times
      • The LED turns OFF
    • Sweep the input through the maximum and minimum values
    • Calibration finishes automatically if no new max or min values are registered for two seconds
      • The LED turns ON
  • If you disconnected an external source:
    • Click the button three times
      • The LED turns OFF
    • Move the knob all the way up and down a few times
      • The LED turns ON

miniMO automatically saves the calibrated values to memory and recalls them if you turn it OFF and ON again

CALIBRATION TROUBLESHOOTING

Problem: When connected to an external device, calibration is lost after turning the OSC OFF and ON again

  • Solution: Disconnect any cable connected to the I/O 4 before turning it OFF
    Alternatively, turn OFF any device connected to the OSC I/O 4,
    or make sure that said device is not sending any signal to OSC I/O 4 before turning the OSC OFF

BATTERY CHECK

When you switch the module ON,

  • If the LED blinks once, the battery is OK
  • If the LED blinks fast several times, the battery is running low