Actually I see no reason why the Raspberry Pi GPIO header could not be used as PC parallel port.
Apart from that you could modify the Linux parport driver...
There are a lot of industrial small PC boards that the use parport to steer machinery. This can replace those with a smaller footprint, and better and more up to date video.
Kernel developers?
ed as PC parallel port.
er machinery.
o date video.
Yeah, you could bit-bang the port to make it work like a parallel port. Or serial port. Might be a good "core machine" for a linux- based CNC controller. A lot of these machines are older PCs controlling a motor drive board through the parallel port. The electronics for such is relatively straightforward. Making the linear motion stuff (mechanicals) with tight tolerances is challanging.
On a sunny day (Thu, 14 Mar 2013 10:12:52 -0700 (PDT)) it happened " snipped-for-privacy@gmail.com" wrote in :
There are RXD and TXD signals already brought out on the GPIO header (GPIO 14 = TXD and GPIO 15 = RXD), and AFAIK the Broadcom chip has an internal UART, so for serial all you need is one of those 3.3V MAX-IM chips, or use a MAX-Pantel circuit:
I did this for the Beagle Board, put in bidirectional level translators and control inputs to them. I needed to emulate EPP (IEEE-1284) port handshaking, and did it with a little bit of user-space code. it worked well.
Jon
PC parallel port.
machinery.
video.
You can do that yourself. Writing such a driver is peanuts! I wouldn't be surprised if there is already a driver which can make a parallel port out of GPIO.
-- Failure does not prove something is impossible, failure simply indicates you are not using the right tools... nico@nctdevpuntnl (punt=.) --------------------------------------------------------------
used as PC parallel port.
teer machinery.
to date video.
doing a parallel port is only part of it, to do a CNC controller you also need an accurate timer to control it
though it is possible, MACH3 run on windows, with a special kernel driver I assume LinuxCNC with some realtime extension to linux I think
-Lasse
yeah, IEEE1284 is a subset of GPIO
17 GPIO pins is the right amount. is there an interrupt line on one of Pi's GPIO pins? would the 3.3v logic be a problem?
yeah, perhaps write a parport_rpi that presents the same interface as parport_pc, and make a "plate" with a DB25F
not I, I've only touched about 12 lines of the kernel, fixing serial drivers both times.
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On a sunny day (15 Mar 2013 21:54:56 GMT) it happened Jasen Betts wrote in :
I remember something about an interrupt, but do not see it here. The 3.3V out would be no problem, my PC mobo also gives only
3.3V out on the parport, about input 5V tolerace I dont know, could be a problem if that is in the spec, maybe need some buffer, could be a very small PCB on a connector that fits in P1 header, that could have a MAXIM serial chip too. I do not really need it myself, will use the i2c though, that is also on this connector, but perhaps I will just bit bang the i2c, not use the hardwareRight you beat me to it :-)
I did some thing on the old audio driver, OSS, just added 48kHz support for some soundcard.
Writing a kernal module that you can then just insert from user-space is easy, I tried a nice tutorial I found on the net, create a device, it is all in there.
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