Free program

The Mahala Workshop - CNC Controller

The program we use to run our own laser CNC in the workshop. It is made for CNC machines people built themselves with Arduino and Grbl, and it is free for everyone. It runs on Windows, and the CNC can be watched and stopped from a phone too.

Download for Windows Step-by-step guide

Version 1.0.3 · 72 MB · released 10/31/2026 · Windows 10/11, 64-bit

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CNC Controller on the computer: state, job, drawing and manual control

What the program does

Grbl 0.8, 0.9 and 1.1

Works with Arduino and Grbl, old and new. It recognises the version by itself, explains errors and alarms, and reads and changes Grbl's settings ($$).

From your phone

The same page on your phone: in your home network you scan a QR code, with no account and no internet. Pause and emergency stop are always at your fingertip.

Resume after a restart

If the Arduino restarts (power glitches, USB), the program restores the position and continues the job where the laser stopped. It can do it by itself while you sleep.

Drawing, frame and time

The job's drawing with the finished part and the laser live, a frame to check that it fits on the material, and an estimate of the time left.

Laser

Laser power (S) for Grbl 1.1, laser mode, switching the laser on and off, and converting ArtCAM files for the laser.

Simulator to try it

A built-in simulator plays Grbl 0.8 and 1.1, so you can try the program without a CNC.

CNC Controller on a phone

The CNC on your phone

Turn on "Local network" in the program and scan the QR code: a phone on the same Wi-Fi opens the same page as on the computer. The 6-digit code is entered only once, and nobody else on the network can control the laser.

The program speaks English and Bosnian. One click changes the language, on the computer and the phone together.

What you need

  • A computer with Windows 10 or 11 (64-bit). .NET and everything else comes with the installer.
  • A CNC or laser with an Arduino (Uno, Nano...) and Grbl 0.8, 0.9 or 1.1.
  • A USB cable; for most Arduino clones the CH340 driver (Windows usually has it already).
  • For the phone: the same Wi-Fi as the computer.

Installation and new versions

Download and run the installer. It installs without an administrator and puts a shortcut on the desktop. The program isn't signed with a paid certificate, so the first time Windows shows "Windows protected your PC": click "More info", then "Run anyway".

When a new version comes out, the program says so at the bottom of its window, and one click downloads and starts it. Your settings stay.

Lasers are dangerous. Wear safety glasses for your laser's wavelength, keep a fire extinguisher within reach and work with fume extraction. "Emergency stop" in the program does not replace a physical emergency stop switch on the machine. The program is free and you use it at your own risk.

What's new

Version 1.0.3 10/31/2026

The program window now always shows the same page as the phone; the old view with plain Windows controls has been removed. Grbl settings can be saved to a text file ("Save to file"), both in the program and on the phone. The log in the window also shows the first messages from when the program started.

Version 1.0.2 10/31/2026

The terms of use have a new "Privacy" part and are shown once more. The only connection the program makes on its own is to mahalaworkshop.com, to check for a new version, and this can now be turned off with the "Check for new versions" box.

Version 1.0.1 10/31/2026

On a narrow phone screen, a three-digit position and the remaining time are no longer cut off. "Compressor pause" is now called "Planned pause". The first version built on GitHub from the public source code (github.com/SenadKulo/mahala-cnc-controller, GPL-3.0).

Version 1.0.0 10/29/2026

First public version: Grbl 0.8 and 1.1, English and Bosnian, access from a phone in the local network, resuming a job after a restart, an installer with automatic updates.

Frequent questions

Yes. No payments, no ads, no account. It was made for our workshop and we share it with everyone who built their own CNC.

Install the driver for the board's USB chip: most clones have a CH340 (the driver is on the maker WCH's website), originals an FTDI or 16U2. In Device Manager, under "Ports (COM & LPT)", a port must appear. Try another USB cable too: some only charge.

Most often the port speed is wrong: Grbl 1.1 runs at 115200, Grbl 0.8 at 9600. If it still doesn't work, the Arduino may not have Grbl on it: the guide explains how to upload it.

That is because the program isn't signed with a paid certificate. Click "More info", then "Run anyway". Download the installer only from this page.

The phone and the computer must be on the same Wi-Fi. In the "Local network" window click "Allow in firewall" and check that Windows treats the network as private. If your antivirus has its own firewall (ESET, Kaspersky...), allow port 8090 in it. Company and hotel networks often don't let devices see each other.

Usually because of power glitches, e.g. when a compressor or a vacuum cleaner starts on the same circuit. Turn on "Resume by itself after a restart": the program restores the position and continues. In the long run, a better USB cable with a ferrite and a separate power supply help.

Grbl 1.1 lights the laser at the power S, which is S0 after a reset. Enter the power in the "Laser power (S)" field. If laser mode is on ($32=1), the laser is lit only while moving.

Step-by-step guide

A question or an idea?

Write to us on WhatsApp: help with the program, a bug you found, or an idea for what to add.

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