Is this discussion that mentions rk3328 still about still BeagleBone Black or a different ARM based device. Maybe for that the subject line should change?
I looked at the Xylotex pin map and I can see only one SPI port that is available although the pin use is commented out in the HAL. For I/O expansion I'm interested in using the Homann Designs MODIO board since I have one. Peter Homann tells me that several people have ported it to EMC2. I also have a CBB-Serial CAN/Serial 232/485 Cape from Logic Supply. With Controller Area Network (CAN) I'd have access to CANopen hardware. I found the site with the files and I've downloaded the various folders. The makefiles will need some work to change paths from EMC2/. . . etc. but it looks like it would work if UART1 P9-24, P9-26 are used. However, my CBB-Serial uses P9-24, P9-26 for CAN and P9-21, P9-22 for UART2. So it should be possible to use some of the cape except that P9-15, which is Z_Step, is use for RS485 direction which implies probably only RS232 MODBUS. Assuming those can be disabled in the CBB-Serial configuration. That will be a set of questions for the BBB group since the EEROMs on each Cape select which device tree information to use. Still, Effectively, unlimited within reason I/O expansion is easily available with a Beagle. John >From CBB-Serial Cape: Signal name Header Pin Pin Mode Comments UART4_RTS(1) P8_33 output UART4 request-to-send UART4_CTS(1) P8_35 input UART4 clear-to-send UART2_CTS(1) P8_37 input UART4 clear-to-send UART2_RTS(1) P8_38 output UART2 request-to-send ON_SW P9_9 input Trigger power on UART4_RX(2) P9_11 RS232 input ±1.6 - ±12V on IDC10 / screw terminal UART4_TX(2) P9_13 RS232 output ±5.4V out IDC10 / screw terminal UART4_RX(2) P9_11 serial in from RS485 -7 - +12V common-mode voltage on receiver UART4_TX(2) P9_13 serial out to RS485 Standard RS485 5V differential driver output GPIO1_6 P9_15 digital output for software RS485 RE/DE control UART2_TX P9_21 RS232 output ±5.4V out IDC10 / screw terminal UART2_RX P9_22 RS232 input ±1.6 - ±12V on IDC10 / screw terminal DCAN1_RX P9_24 serial in from CAN bus -27 - +40V common-mode voltage on bus DCAN1_TX P9_26 serial out to CAN bus 3V max driver differential output voltage NOTES: 1. These pins are shared with the HDMI driver and are disabled by default. See Enabling Flow Control below 2. UART4 is shared between the RS232 converter and the RS485 driver, its function is selected with jumper >From DB-25/26 Cape: Enable System P8.07 out STOPin P8.09 in XLIM P8.10 in X_Dir P8.11 out X_Step P8.12 out PWM0/SPINDLE P8.13 out YLIM P8.14 in Y_Dir P8.15 out Y_Step P8.16 out ZLIM P8.18 in PWM1 P8.19 out PWM2 P9.14 out Z_Step P9.15 out Z_Dir P9.23 out #SCS P9.17 out #SDI P9.18 in #SDO P9.21 out #SCK P9.22 out A_Dir P9.13 out A_Step P9.11 out > -----Original Message----- > From: Gene Heskett [mailto:ghesk...@shentel.net] > Sent: October-09-17 9:36 AM > To: emc-users@lists.sourceforge.net > Subject: Re: [Emc-users] MachineKit on the BeagleBone Black > > On Monday 09 October 2017 11:45:58 Nicklas Karlsson wrote: > > > > > There ARM M is tiny and dirt cheap and is very good for real-time > > > > work. I have a robot with four motors and encoders and get 44,000 > > > > interrupts per second > > > > and much better real time latencies then from any Linux based > > > > solution on any platform. > > > > > > > > My solution for robot control is a hierarchy with ARM M for the > > > > lowest level, then > > > > Raspberry Pi 3 connected by high speed serial. > > > > Right now I am at this point with high speed serial communication to > > ARM for the lowest level. > > > > > I did succeed in building a fully rt-preempt 4.9 kernel on it today, > > > took about 4 hours, but I've not yet attempted to boot it as I saw > > > some stuff go by during the build (when I wasn't checking my eyelids > > > for leaks :) that I yet need to turn off. I think, other than fine > > > tuning the kernel build, that convincing the hm2_rpspi driver that > > > it should run on the rock's rk3328, arm64 quad core SoC, running at > > > up to 1.5GHz should be the last major hurdle to making linuxcnc run > > > on it, ... > > > > Happen to know how many SPI ports there may be? > > > This driver that Bertho Stultans wrote, can do 5. Over 2 pin groups IIRC. > However since I was the lab rat, only the SPI1 set has been extensively > tested. > > From the bottom of the pi's 7i90-axis.ini file: > [HOSTMOT2] > DRIVER = hm2_rpspi > BOARD = 7i90 > CONFIG = "num_encoders=4 num_pwmgens=2 num_stepgens=4" > ----------------------------- > and from the top of the .hal file: > # hostmot2 driver > loadrt hostmot2 > > # load low-level driver > loadrt [HOSTMOT2](DRIVER) config=[HOSTMOT2](CONFIG) spiclk_rate=41666 > spiclk_rate_rd=25000 > ----------- > The above is all one line > the "rates" are the write, and read, clock rates, corresponding IIRC to a > 41 megabaud write to the 7i90 rate, and a slower 25 megabaud rate for > reading back the data from the 7i90. > > Both of those rates could probably be improved with stronger, as in > faster rise and fall times in the pi's pin drivers, they are a tad puny. > > The interconnect cable between the pi and the 7i90 is only about an inch > long, achieved by mounting the pi upside down on 1" tall nylon standoffs > and the header connections aligned with the 26 pin socket on the 7i90. > Just in case, an old video card fan is mounted under the pi, running on > the pi's 5 volt supply. > > The 7i90 is the bottom of the stack in that box as there's 3 7i42TA's > stacked over the 7i90, between the 7i90 and the real world. Stops all > that noise & overvoltage BS that blew several 7i90's by the time I > understood that I just couldn't put it in the same box with the stepper > & vfd stuffs. In a separate box, the noise is quite low, and not > sufficient to effect operations in any way. > > > Regards Nicklas Karlsson > > Cheers Nicklas, Gene Heskett > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > Genes Web page <http://geneslinuxbox.net:6309/gene> > > ---------------------------------------------------------------------------- -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
