A simple CNC (Grbl) gcode sender designed tob e used on a 480x320 touchscreen and a joypad.
Note: This release is yet not thoroughly tested. Please use at your own risk! Soon a tested release will be uploaded
The program requires a computer and a monitor, preferably a Raspberry Pi 2 or better and a 480x320 touchscreen like this one from Adafruit.
Moreover, python 2.7 is required with the following additional modules:
- psutil
- PyGame
- PySerial
- PySide (and Qt libraries)
For better performance, PyGame can be patched to avoid echoing the joystick commands, but this is not necessary. See https://bitbucket.org/pygame/pygame/pull-requests/6/fixed-joystick-debug-printouts/diff
The program is started by the following command line:
python cncController.py [-f] [-d]
The following command-line options can be used:
-f or --fullscreen: start the program fullscreen
-d or --dummy: use a dummy Grbl sender (echo to stdout) instead of serial communication
When first started, the program will look for a serial connection to a CNC machine. Once both are found, the program will enter “jog mode”, showing the following screen:
From this screen, the machine position can be controlled and the origin set. The position is exclusively controlled by the joypad, with the following button mapping:
Clicking on “Load” or pressing button 10 on the joypad, opens the file selection:
In this mode, the mounted partitions (drives) are shown on the left pane, and the current directory is shown in the right pane. A file can be selected via mouse/touchscreen, or using the hat buttons of the joypad. Button 1 of the joypad selects a file or navigates the directory structure (clicking on a directory will open it).
Once the desired file is selected, press “OK” or button 9 of the joypad to load it. The program will return to the jog screen. “Cancel” does not load any new file.
The file is loaded asynchronously and analyzed; the bounding box of the part is displayed in order to have an idea of the dimensions and check that it will fit in the available stock. An estimation of the printing time is given.
Once the proper origin for the part is selected, pressing “Run” or button 9 will run the job, and the program will enter the following “Run” mode:
The estimated time is replaced by a progress bar, and a stop button appears for emergency stop. Button 9 of the joypad will also quickly stop the job. In case of stop, the position reference is lost and the machine is reset.
The “Pause” button (button 10 of the joypad) stores the current position and temporarily enters the jog mode; the user can then move the machine position. When “Resume” is clicked (button 10), the machine will safely move back to the stored position and resume the job.
Important note: the displayed position information is in millimiters. The program should be able to correctly interpret gcode files in imperial units, but additional testing is required. Estimated time and Pause commands might not work correctly with imperial units.
The program is designed to work with a joypad. However, jog commands using a numeric keypad are also supported. Only 1mm movements are supported at the moment and the key mapping is the following:
- 4,6: X movement
- 8,2: Y movement
- 9,3: Z movement
- 5: Go home
- 0: Set home
- Enter: Set Z=0
You can also write your own joggers to support more devices. Please see the Joggers/AbstractJogger.py file for more instructions.
The software supports the host command @pause, which can be prefixed by a ; or enclosed in parentheses ((@pause)), in the running GCode to insert a pause in the execution of the program.
The application can be configured by modifying the cnc_config.py file. Many aspects can be configured, including:
- Serial port and baud rate
- Joypad button mappings (note that the buttons start from 0, so button 1 is defined as 0 in the configuration)
The configuration allows the definition of a standard G0 feed rate for the calculation of estimated time; however, the program will attempt to read the actual value from the Grbl configuration at runtime.
The software is designed to run on a Raspberry Pi and a 480x320 touchscreen. Smaller touchscreens are not suitable for the interface. Also, the program cannot run without a joypad.
In order to make it pretty, I used a 3D-printed case that can be found here.
A ready-made image for a RPi2 can be downloaded from my website.
Here's a picture of my setup:
The program is licensed under GPL v3. Please see LICENSE.txt for details. The following files contain code from other people:
- GrblWriter.py: contains code from Will Welch, https://github.com/welch/shapeoko
- GCodeAnalyzer.py: contains code from RepetierHost, repetierdev@gmail.com (Licensed under Apache 2.0 License) Please see the sources for further details on licensing.
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