Would you participate to an open-source CNC controller?

[eSilviu]

Hello
I have one idea: an open source CNC controller, with ethernet interface.
It will use cheap microcontroller and FPGA, and work with windows and linux. The biggest problem is to implement g-code compiler in FPGA.
Processing power is not a problem any more but I don't have time to fully understand and develop software for this, although I have previous experience with CNC, ethernet microcontrollers and FPGA design.

I could post schematic (but FPGA it's not fun to solder), and current development files.
How do I make sure that project remain open-source?

[beliefdrive]

what FPGA chip you plan use?

[eSilviu]

what FPGA chip you plan use?

XC3S250, package is TQFP144.
For now I have a Digilent "Basys" development board, with XC3S100 FPGA from Xilinx.
I know that ethernet can be implemented in FPGA too, but I didn't tested this yet.

[beliefdrive]

i thinks we need begin with interpolation algorithms

[eSilviu]

If anyone can implement the necessary ETH module in FPGA, it will be perfect.
Here is a good start:
http://www.fpga4fun.com/10BASE-T0.html

The real advantage of FPGA is that modules are working separately, so if something is bug-free - will not be affected if oter module is modified.

[eSilviu]

i thinks we need begin with interpolation algorithms

Yes. but I suspect this algorithms are already implemented somewhere, close to what we need.
1. My idea is that FPGA receive a g-code line, and interpret-it.
2. One advantage will be if the X/Y/Z/A/... coordinated are expressed in stepper's steps. It can be implemented right from the program that generates g-code.
3. A Java applet will take that file and send-it line by line to FPGA through ethernet. This way any operating system can be used.
4. Any new computer can be used, from anywhere in the local network with CNC controller (no need for parallel port, USB, or RS232)
5. There will be no need for optical isolation between computer and controller (ethernet is enough)
6. Java (although big and somehow slow) can do almost anything - from talking through ethernet to real-time animation of the CNC tool.

[beliefdrive]

i found same article on fpagfun, it is usefull

http://www.fpga4fun.com/CNC.html

[andy55]

Have you looked at the mesanet.com 5I20 and similar FPGA PCI-cards.
They are currently being used with EMC2 and there is open-source VHDL for PWM-generation, encoder counting, step generation etc. There is also a "softdmc" motion-controller implemented for this FPGA.

On the EMC2 list there has been talk about a real-time (RTAI) port of Linux for the beagle board (http://beagleboard.org/). This could be another way of approaching embedded motion-control.

I would encourage you to seriously look what EMC2 already has and how you can extend that to what you want or how you could use parts of it.

[eSilviu]

Have you looked at the mesanet.com 5I20 and similar FPGA PCI-cards.
They are currently being used with EMC2 and there is open-source VHDL for PWM-generation, encoder counting, step generation etc. There is also a "softdmc" motion-controller implemented for this FPGA.

On the EMC2 list there has been talk about a real-time (RTAI) port of Linux for the beagle board (http://beagleboard.org/). This could be another way of approaching embedded motion-control.

I would encourage you to seriously look what EMC2 already has and how you can extend that to what you want or how you could use parts of it.

I want an embedded CNC controller, with ethernet interface and a small LCD, that can be used with any operating system.
I know about EMC, I don't want to design a new plugin for EMC or MACH or any other software. That are good solutions with their good and bad parts.

[andy55]

Why wouldn't the beagle-board, running real-time linux and EMC2 qualify ?

If you want to write your own real-time operating system, g-code interpreter, graphics drivers, PID-loops, etc. etc. etc. then please go ahead, but unless you are very talented and have lots of resources (time+money) it will be difficult.

To me it seems the real-time port for the beagle-board would be an excellent way to go.

[eSilviu]

Why wouldn't the beagle-board, running real-time linux and EMC2 qualify ?

If you want to write your own real-time operating system, g-code interpreter, graphics drivers, PID-loops, etc. etc. etc. then please go ahead, but unless you are very talented and have lots of resources (time+money) it will be difficult.

To me it seems the real-time port for the beagle-board would be an excellent way to go.

why do you want to make things heavier than it can be?
There is no reason to implement a real-time operating system.
Any problem from this idea can be solved at low-level.

[andy55]

if you want to receive G-code over ethernet, interpret it, show it on screen, and run a machine you need a lot of the software components that are already there in place with a linux+EMC2 solution.
IMO working on an fpga-based kick-ass I/O module for the beagle-board would be time more well spent.