Thread: Raspberry Pi
Anyone else bought one?
Got mine up and running on Debian Wheezy.... now just thinking about a project for it... stand-alone g-code interpreter and drive controller to replace PC running MACH3. Using Python as the programming language since its built in and doesn't need to be compiled with a seperate build machine. And since Python is interpreted it is easy to experiment with. Also Python has very good set/array/list manipulation which should make it easier to write the code.
Already got it set up so I can view/control/program it remotely from both my Asus tablet and my PC over the network.
I've just got one too, so naturally I'm thinking if it's possible to do the same project with it.
The simplest way would be to get LinuxCNC to run on it, but that's not likely. This thread discusses various issues:
I work on firmware for stepper drivers, for 3D printers. The RepRap 3d printers usually use some form of Arduino to receive GCode and drive the steppers.
Raspberry Pi is a great little bit of hardware for the price, and naturally people want to use it as a PC replacement in all sorts of projects. Unfortunately, the Pi falls between two stools. It is quite underpowered compared to desktop PC, but if running Linux has too much baggage for a real-time controller. So I think it would be a struggle to get LinuxCNC running nicely on it, though I am sure someone will try ;)
If you don't run Linux, then you lose all the goodies that Linux provides, and also access to graphics acceleration via the GPU. The GPU is effectively closed as Broadcom only give specs under NDA to volume customers. However, several people are looking to port non-Linux realtime OS to the Pi.
The I/O on the Pi is quite limited too, without extra hardware. It is not possible to buy the Broadcom chip and spin your hardware either.
I am pretty sure someone will turn it into a stepper driver, the MIPS/$ for the stock Pi is unbeatable. In our printer project we are looking to see how we can use the Pi. Either as a host interface or as stepper controller.
I am still waiting for one to be delivered!
I think you might do better with one of the ARM development boards.
I got one for my plasma cutter. It has a little touch screen, USB, serial, memory card socket to plug in GigaBytes of extra memory , buttons, LED's and a squeaker all powered off the USB cable.
TI even have a stepper driver dev board with all the bells and whistles plus sample code. List is £80 but someone will sell them cheap eventually.
The GNU compiler is free, gives unfettered access and runs under Windows.
I've had mine for a while now and looked into this and the problems i have seen so far is limited number of I/O pins (10), The need to build a new kernal to support the Arm processor for realtime use. I am still sure though somebody clever will iron these out at some point to have a basic controller of sorts?If the nagging gets really bad......Get a bigger shed:naughty:
I am using the R2C2 controller board designed for 3D printers, it has 100 MHz ARM plus 4 axis stepper drivers using A2988 chips. I did a video here http://www.youtube.com/watch?v=HAKubJFlKuE&feature=plcp
Interestingly enough Mike Cook has recently done a little BOB for the raspberry pi:
He hasn’t had his long, however looking at his “portfolio” he has also done a CNC Conversion converting a Proxxon MF70 machine to cnc and then building his own version of the RepRap controller, a unit also based on the Arduino:
well i've read just about everything I can find on LinuxCNC et al ports to the Pi. Seems its possible but some way away. Sadly my knowledge of Linux is insufficient to do such a port myself. I was thinking more of a stand-alone solution along the lines of FASM or DEX-OS...
And very nice to have you back, Sir. I think the Raspberry could be a bit of a red herring, I think you really need an ARM processor on a board with a crystal, USB socket, IO pins and the six pin header that puts in the USB loader so you can program it live.
The problem is getting started, but once past the "Hello World" stage you should be on a roll. The processors start at a couple of quid, if you stay below 60MHz they are dirt cheap. If you fancy a collaboration I am your man.