Sequencer

Sequencer, Oscillator, and ADSR (all three are miniMOs)


miniMO's Sequencer is an analog CV step sequencer/arpeggiator with real time tempo control and easy step edition.

SOURCE CODE

Download from Github

FEATURES

  • Configurable number of steps
  • Configurable scales
  • Real time Tempo control
  • Step Edition Mode with real time note and length control
  • Random sequence generation on start up
  • Automatic Calibration Mode
  • Automatic Battery check

MANUAL

I/O

  • 1&2: Outputs - control voltage for frequency
  • 3: Input - frequency (during calibration)
  • 4: Output - gate (note ON/OFF)

MODES OF OPERATION

PLAY (default)

The sequencer plays through all the steps

  • Knob: change tempo
    • miniMO waits until you reach the value it has currently stored
  • Single click: go to EDIT mode
    • To edit a step, click the button during the PREVIOUS step
  • Triple click: go to frequency calibration mode (see below)
  • The LED turns ON and OFF to mark the steps

Each time you turn the module OFF and ON, miniMO plays a new random sequence

EDIT

The sequencer repeats the current step indefinitely at the tempo set in PLAY mode

  • Knob: change note frequency
    • miniMO waits until you reach the value it has currently stored
  • Single click: go to PLAY mode
  • Double click: change note length
    • Three note lengths are possible: half(staccato), silence, and full(legato), in this order
    • By default, the notes are set to half
    • Full notes don't send a "note off" signal. This is most useful in combination with the envelope module
  • The LED stays ON continuously

FREQUENCY CALIBRATION (With an Oscillator Module)

When you enter this mode, miniMO starts an automatic procedure and calibrates its output to send values that result in the target frequencies defined in the program

  • Before calibration,
    • Connect the sequencer's I/O 1 or 2 to the oscillator's I/O 3 (sequencer note output to oscillator frequency input)
    • Connect the sequencer's I/O 3 to the oscillator's I/O 1 or 2 (sequencer calibration input to oscillator frequency output)
    • Connect the sequencer's I/O 4 to the oscillator's I/O 4 (sequencer gate output to oscillator volume output)
    • Turn the sequencer's knob all the way counter-clockwise and make sure the arrow points at the button
    • Turn the sequencer's knob halfway (arrow pointing at I/O 4)
  • Click the sequencer module's button two or three times to start the calibration procedure in the sequencer
  • Start the oscillator calibration procedure (refer to oscillator manual on how to set it up)
    • A series of high and low beeps are heard; this calibrates the oscillator module
    • A rising pitch is heard; this calibrates the sequencer module
  • When the pitch stops rising, calibration is finished
    • Disconnect the cable from I/O 3 in the sequencer module
    • Turn the sequencer OFF and ON again. A sequence starts playing ^_^

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

CALIBRATION TROUBLESHOOTING

Problem: Can't start calibration in the oscillator module

  • Solution: Make sure to start sequencer calibration before oscillator calibration

Problem: Calibration gets stuck in an endless loop from the lowest note up

  • Solution: Recheck cable connections and knob positions, then repeat calibration

Problem: Calibration gets stuck in an endless loop towards the highest pitches

  • Solution: Move the knob in the controller clockwise by a small amount and repeat calibration

Problem: After calibration, moving the knob in the controller gives strange sounds

  • Solution: Disconnect the cable between the oscillator output and the sequencer input

Problem: Calibration is lost after turning the oscillator OFF and ON again

  • Solution: Disconnect the cable connected to the oscillator's I/O 4 before turning it OFF
    Alternatively, turn OFF the sequencer before the oscillator,
    or make sure that the sequencer is not sending a note before turning OFF the oscillator

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