I dont want to curb your hopes too much, but I said 'GladeVCP+HAL standalone applications' and meant to say 'HAL only' - i.e. no Gcode, no task, no motion - more loudly
that works and I can recommend looking into especially if the application isnt very time critical (I get something like 45uS latency on the Pi with xenomai) I do use the Pi as an exemplary platform to test configure and build; I dont expect to use it for CNC purposes myself and I'm not investing effort dont waste too much time on seeing a Pi as €35 CNC platform just yet - it's pushing the limits (gut feeling, without having tried I'd say this is outside the Pi's capabilities, and the I/O interfacing capabilities arent that plush) I'd rather look into a BeagleBone or so for real I/O; still soft stepping is a bit meager on ARM's without resorting to tricks like Sergey did in miniemc2 - which is btw worth picking up, but not necessarily by me ;) in case of the BeagleBone it would mean 'program the RT hard stuff in the extra 'realtime RISC cores' which doesnt look like a weekend project either -m Am 20.11.2012 um 17:40 schrieb Anders Wallin: > Good news! > I've ordered a Pi (Farnell re-directs to a local distributor), but the > delivery-time seems to be 3 weeks right now(?) > > It seems that the SPI interface will be most useful for high-speed IO. If I > understood correctly the Pi supports only two separate chips on the SPI-bus, > but on IRC PCW mentioned that SPI is possible on the GPIO-pins also? For a > servo-controlled machine I guess a microcontroller and/or FPGA on the SPI bus > could read encoders, output PWM, and do IO. One would then need a HAL-driver > that is capable of communicating the relevant data over SPI every servo > period (1ms or so). Do you think this HAL2SPI driver will be easy or hard to > write? > What about stepper-machines? Is it enough to communicate a stepper velocity > over SPI to dedicated step-generation hardware? > > In addition to cnc use I'm also interested in stand-alone operation with a > touch-screen, for example this one (HDMI display, USB touchscreen): > http://www.lilliputuk.com/monitors/open-frame/of701-2/ > > Something that boots directly into a Touchy-like custom UI-panel and can > set/watch/plot/etc. HAL-signals would be really nice. > > Anders > > On Tue, Nov 20, 2012 at 4:47 PM, Michael Haberler <mai...@mah.priv.at> wrote: > I just verified this combination works, for the standard Raspberry Raspbian > kernel 3.2.27+ with Posix threads (aka 'simulator'), and with Xenomai 3.2.21 > for somewhat better performance > > both remote X Display and local console work > > this is the rtos-integration-preview1 branch; the only part needed disabling > was the GladeVCP sourceview widget which is lacking the underlying modules > > currently the only hardware driver supported is hal_gpio for wiggling some > pins; the serial, i2c and SPI interfaces would be possible further > candidates, mungkie did some initial work on these > > > I'll see whether I can come up with an SD card image ready to go with all the > parts (xenomai + userland support + linuxcnc prerequisites + linuxcnc built) > > Axis, touchy and friends are still untested > > > - Michael > > > ------------------------------------------------------------------------------ Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
