USB support for GMFC with the GGC adapter

New firmware version 4.01 !!!


  • Generation of a unique GMFC license key, independent of the PC and disk formatting. Having a GMFC license (LIGHT, PRO, EXPERT) is required.
  • Works under any Windows version that supports USB from win98 to Windows 10, including 64 bit Windows versions.
  • 50 KHz internal timer for smooth accelerations. The internal timer allows the support of motor interfaces that don’t have a timer.
  • Compatible with most existing step/dir unipolar and bipolar motor interfaces. Fully configurable Dir/Step outputs. Motor Enable on parallel port pin 1 or 17. Polarity of the Step signal configurable.
  • Wire heat support. The heat LED must be connected for the wire to work.
  • Optional display of the heat and parameters using a LCD display. 1,2, and 4 line LCD displays are supported by the V4 firmware.
  • Support of the RepRap panel using a LCD adapter board.
  • Automated recognition of the interface parameters by GMFC (from version 3.89.14).
  • Full compatibility with the former MMUSB interface.
  • Programming of the MM2001 PIC firmware. The MM2001 firmware MM2001_GGC is required.
  • Configuration through the ggc_utilityV4 software that also allows the programming of the MM2001 PIC firmware.
  • Documentation of the V4 version.

A GMFC license is associated to a single GGC/MMUSB interface. If you need several GGC/MMUSB interfaces, you must buy one GMFC license (and USB add-on) per interface.If you want to upgrade an MMUSB to a GGC interface, there are two solutions:

  • you send me back the MMUSB and I will change the serial number, then you can resell the MMUSB;
  • you buy a new GMFC license and you resell the previous one with the MMUSB.

GGC installation

The GGC adapter is connected to the PC via the USB cable. A USB cable of type B (printer type) is necessary.

Run GMFC (from version 3.89.14). Then open the dialog “GMFC/Table configuration”. In the the “Driver and Hardware interface” frame, select “USB”. The GGC parameters, such as its type and the timer value are automatically recognized.

Note that with the GGC adapter, the timer frequency is specified internally. The timer value is 50Khz (20us).

If you have a MM2001 motor interface and if the wire heat is managed by the MM2001 interface, the heat precision is determined by the MM2001 timer. The frequency of the MM2001 timer should be set to 4Khz.

Details on configuring the GGC interface are described in the online documentation. Please read it carefully.

GMFC license and the GGC

The GGC adapter is supported by all GMFC versions. The GGC adapter provides an unique license key that is independent of the PC and disk formatting. To validate the USB licence, open the dialog “Help/About”.

Now click on the “Get license” button.

Just send me the code, and I will mail you back a license key that will work on any PC. Therefore, the GGC can be shared easily within a club.

The 30 day test period is valid with the GGC board. After that period, you will have to enter the USB license key. You can also test the GGC interface using the ggc_utilityV4 program.

A GMFC license is associated to a single GGC/MMUSB interface. If you need several GGC/MMUSB interfaces, you must buy one GMFC license per interface.


The GGC interface is now sold by me, check the shop page.

For US customers, the GGC is sold by Dan Field. Please contact him by email for shipping cost and order. Y
ou will also have to buy a USB software extension (25 euros) from me, check the shop page .

2 thoughts on “USB support for GMFC with the GGC adapter

  1. Hello
    Dear Sirs
    I am Japanese and can not understand English.
    I have you guide the instruction “ documentation / GGCV2_doc_en.pdf” from you.
    However, since “pdf” documents can not read the order of delimiters properly, google translation is difficult and does not work.
    If I can see the “html” document, the google translation will be more correct.
    Also, since the length of one line is long, I can not grasp the content or pulse.
    If possible, please delimit it shortly and explain with sentences.
    The end of the line ends with “.”, Please use other symbols in the end.
    Best regards

    1. Would a word document work for you?

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