MC-1 - MIDI-Clock Generator for VMC


MC-1 is a software to run on the VMC-system. It provides a MIDI Clock generator. 

  • Download the latest version of the Arduino code . This download is a zip-archive. Unpack it. It will contain a directory ./MC-1/ which contains three files. Start the Arduino IDE and open the *ino-File. The other two files will be loaded automatically. The upload function will transfer all three files at the same time.
For the Installation please use the ARDUINO IDE, see An introduction how to upload the program with the Arduino IDE can be found here.

The software is based on the uClock library by Romulo Silva <>, Manuel Odendahl <>. The uClock core is published under MIT license, the user interface written by me (Florian Anwander) is published as open source under the creative commons license 'by-nc-sa 4.0'

MC-1 - Users Manual

Firmware Version 1.0
VMC-1 Hardware Version 1.5.4

'MC-1' is a programm for an Arduino Nano mounted on a “fanwander VMC-1'. The programm generates MIDI-Clock in variable tempo from 20 BPM to 275 BPM. The tempo can be changed either continously or can be preset and the change is invoked by a button press.
Also one can send MIDI Start and MIDI Stop commands - either by buttons or by incoming triggers. The MIDI-Clock continues running even if the status is STOP

If your VMC-1 runs a different software at the moment, then please consult the programming instructions for the VMC-1 on how to install software. In this case you have to perform a 'Factory Reset' as described in the section 'setup menu'.
You may should check the instruction for 'Adjust Poti-CVs' in the section 'setup menu'.


...for those, who think they don't need manuals:
  • The function of the five buttons

    Stop Mode PLAY
    realtime tempo change
    send tempo change -10 tempo +10
    -1 tempo +1
    Play Mode
    STOP realtime tempo change
    send tempo change -10 tempo +10
    -1 tempo +1

    Setup Mode (* see below)
    Select Param
    Exit Setup
    < Parameter >
    Set Param

    -- Value ++
    (*) at the moment there is no parameter to setup, so there is no setup-menu
  • Good Luck :-)
Now more details for the patient ones...

Connect and Configure the Hardware

This is described in the users manual of the VMC-1.

MIDI connections

Basically you need only a device which receives MIDI-Sync (I will call this 'the sequencer'). I will not explain how to connect MIDI devices. So establish the following MIDI connections

VMC-1-MIDI-Out <-> Sequencer-MIDI-In.

At the moment there is no setup function. The software runs as it is.

You have to setup your "sequencer" (or what ever you want to control by the MC-1) to receive MIDI-Clock and MIDI-Start/Stop commands. Since this depends completely on your device I cannot provide detailled help. Usualy this is called like "external clock".

Generic Function

On power up the display will report its version and then it will look like this:

STOP current=120
pot=192 btn=20

The display shows:
  • upper row left: the status 'PLAY' or 'STOP'
  • upper row right: the tempo currently sent out.
  • lower row left: the value provided by the tempo-knob
  • lower row right: the value provided by the buttons F1/F2

Setting the Tempo

There are two modes to set the tempo: the preset mode and the real time mode.

For the preset mode you do either:
  • Set the tempo using the buttons F1 (=decrease) and F2 (=increase). Pressing only one button changes the tempo for 1 BPM. If you press and hold one button and press then the other button, the tempo will change for 10 BPM. => The value btn=... will change accordingly.
  • Now press WRITE. => The currently sent tempo will jump to this value
  • Set the tempo using the TEMPO knob. => The value pot=... will change accordingly.
  • Now press and hold WRITE and then press F1. => The currently sent tempo will jump to this value.

For the real time mode press and hold both WRITE and F1 and set the tempo with the TEMPO knob. To avoid unwanted jumps in the tempo change, you should set first the TEMPO knob to the value that is displayed as "current" and do the real time change then.


To send a MIDI-Start-command press the play button.


To send a MIDI-Stop command press the stop button.
Remark: this will send only the stop command. The clock will continue running. This is recommended by the MIDI specification, and is urgently required for many devices.

Setup Mode

At the Moment there is no setup menu

All product names and brand names beside “VMC-1”, “ChordTrigger” and “fanwander” belong to the corresponding owners. They are mentioned only for educational purposes.

All rights reserved, by Florian Anwander 2020 - 2022