My first steps with LinuxCNC - comments appreciated :) Using Mesa 7i80 and 7i78

Hello,
I’m completely new to LinuxCNC and wanted to document the initial setup of my MESA cards. As this was not completely straight-forward I hope these notes might help other beginners. Also, maybe someone can tell me what I could have done better in this process.

I got most of my guidance from watching talla83’s YouTube videos (I’m German too), however some of them were a little old and most didn’t apply to my specific setup, So while the videos were quite instructive and helped a lot, they didn’t get me all the way to a working configuration.

I had planned to buy a 7i76E. however I couldn’t find any distributor with stock, so instead I bought a 7i80DB-25 and a 7i78 daughter card. At this point I mostly wanted to get the basic 3 axes and a spindle going, plus some switches.

The initial readout of the card (mesaflash … —readhmid) showed that all pins were configured for Smart Serial and MuxedQ, so not exactly what I needed for a simple stepper configuration. The 7i80 manual said that a 7i78x4 configuration would be provided, however I couldn’t find it included in the support software ZIP. The latter also didn’t contain any .pin files to get an idea which .bit file might be appropriate. 

I’ve contacted the Mesa support about this, but also wanted to move ahead, so tried some stuff in the meantime. So I flashed a few .bit files and read them back until I found one that included a simple stepper configuration (7i80db_25_7i76x3.bit).

Next, I wanted to try my luck with the PNCconf Wizard. At my first attempt I didn’t see my board listed in the configuration page. So I wondered wether I could simply copy the 7i80's .bit files into /lib/firmware/hm2 to make it show up in the menu. I got the board into the menu after PNCconf asked me about the number and typeof connectors, but the firmware files weren't visible in the menu below. I assume this requires a matching .xml file?

Writing my own .xml file felt a little too ambitious, so I continued with “7i80HD-Internal Data” and the “SVST8_4” firmware. This doesn’t quite match the .bit file I flashed to the board, but I wanted to complete the process to have a look at the .hal and .ini files, maybe edit them a bit to make things work. And indeed the only thing I needed to change was to replace all instances of “hm_7i80hd” with “hm_7i80”. After that LinuxCNC started just fine and I got pulses on the connector as specified in the .bit file I flashed.

The spindle PWM doesn’t work yet, but that’s for tomorrow

Happy about any comments.
All best,
Sukandar
 

I can make a 7I80DB-25 7I78 bitfile in the next day or so.

Note that you can make you own .pin and .xml files with mesaflash and the --readhmid and --xml commands

Thanks for the quick reply and the offer - that would be nice to have

I'm also interested in learning how to make .bit files myself. Is the information here still up-to-date: wiki.linuxcnc.org/cgi-bin/wiki.pl?Editing_MESA_Bitfiles ?
I do have FPGA experience, however mostly Verilog. Also it's 30 years ago that I worked with Xilinx chips. Been using mostly Altera and Lattice.

sukandar wrote:

I'm also interested in learning how to make .bit files myself. Is the information here still up-to-date: wiki.linuxcnc.org/cgi-bin/wiki.pl?Editing_MESA_Bitfiles ?

well, that was easier than I thought - just compiled my first few bitfiles. So far everything seems to work fine. So you don't need to generate one anymore, but thanks again for the offer

PCW wrote:

I can make a 7I80DB-25 7I78 bitfile in the next day or so.

no longer necessary, but thanks again

Note that you can make you own .pin and .xml files with mesaflash and the --readhmid and --xml commands

I tried this and indeed could generate an .xml file, however when I copied it into  /lib/firmware/hm2/7i80 I still couldn't select it in the PNCconf Wizard. This is the error message I got:

Traceback (most recent call last):
File "/usr/bin/pncconf", line 2027, in on_mesa_boardname_changed
self.fill_firmware(boardnum)
File "/usr/bin/pncconf", line 2036, in fill_firmware
self.mesa_firmware_search(title)
File "/usr/bin/pncconf", line 916, in mesa_firmware_search
self._p.FIRMDIR,boardtitle,currentfirm+".xml"))
File "/usr/bin/pncconf", line 1055, in parse_xml
tempfunc = tempfunc.upper().strip() # normalise capitalization: Peters XMLs are different from linuxcncs
AttributeError: 'NoneType' object has no attribute 'upper'

I think for the moment I'll familiarize myself more with the .hal and .ini file syntax rather than worrying about the Wizard, but I'd still be curious how this could be made to work

thanks,
Sukandar

Did you try pncconf's "discovery" option?

You mentioned using Xilinx to create your own bit files.  How do I identify the appropriate .xise file to start with?  I have a 7i92M Mesa Board.  I would like to customize the pinouts to best use a breakout board that I am using.  Also, can this be done only using Mesaflash?

Thanks,

Bill W.

You would use the seveni92.xise project

Mesaflash is used to write and check the bitfile you created with the Xilinx tools

I did and I could use 1 or two of those configurations with some work arounds with the wiring but it would not be ideal.  I thought it was a good time to learn a bit more about the process.

Thanks for the reply!

Bill W.