GRBL SIM

What can you do with Grbl Sim?

• Simply check out how Grbl works without needing a microcontroller.
• Visualize a g-code program by having the simulator parse and execute to a GUI. Fluctuations in feed rates by the acceleration planner can be viewed as well.
• A powerful debugging tool for development.
• The microcontroller peripherals are emulated using structs and functions. These could be written to do whatever you need. For example, output simulated step pulses over time and examine its performance.

How do you compile Grbl Sim?

Clone this repositoriy

$ git clone --recurse-submodules <url> 

Create a build directory

$ cd Simulator
$ mkdir build 

Run cmake and create the binaries

$ cd build
$ cmake ..
$ make

Debugging on LINUX

On Linux, hook it to a fake serial port (/dev/ttyGRBL) and use it to test your Grbl interface software:

socat PTY,raw,link=/dev/ttyGRBL,echo=0,group-late=dialout,mode=660 "EXEC:'./grblHAL_sim -n -s step.out -b block.out',pty,raw,echo=0" 

After this command, the simulator is running and has a serial connection to /dev/ttyGRBL.

With Minicom you can read and write to the serial connection. Let's take a closer look.

First start minicom with

$ minicom -s

in your terminal. Then you will see a configuration window and select the serial port setup.

In the setup press the A key and change the serial device to GRBL.

Now exit the setup and configuration and you will see the connection to our grbl simulator. Press $ + Return for your first help command.

Realtime modifications:

Now simulates microcontroller peripherals in separate thread. Runs in aproximate realtime. Emphasis on * Approximate *. Work is underway to speed it up.

Validator

Run

$ grblHAL_validator GCODE_FILE

to validate that grbl will parse your GCODE with no errors.

Raw telnet connection

NEW

Use the -p <port> command line argument to start a raw telnet server for communication instead of using serial simulation via stdin/stdout. This frees up stdin for input to trigger hardware events such as feed hold, cycle start or setting/clearing limit switches.

Maintainers

• Created by Jens Geisler, Adam Shelly

• Modified by Terje Io for grblHAL. Original implementation for Grbl can be found here.

This repository contains an experimental Grbl simulator that compiles the main Grbl source code into a wrapped executable for use on a computer. No microcontroller required. When the executable is run, the user should be able to interact with the Grbl simulator as if connected to a microcontroller board with Grbl.

WARNING: Grbl Sim is under heavy development. So many things may not work, or respond in ways unexpected. At the moment, this code is a proof-of-concept.