Raspberry Pi 4 with Mesa 7c81

It would require a special bitfile and a special cable
a simpler (though more expensive) would be to add a 7I85/7I85S
and a 7I83, or a 7I77.

I wish we made a simple 25 pin analog/encoder interface

I decided to go with 7c81 + 7i77.

Then I will do what is suggested in this post:
" the easiest way to generate a working hal/ini configuration for the 7C81 is to use pncconf and setup say a 5I25+G540 configuration. Then change the card name in the .ini file and driver name in the hal file".

One more think. What cable/connector I need to buy to connect 7c81 to 7i77.

Thanks

If 18" is long enough, Mesa's DB25M-IDC26 CABLE should be correct

hey! i was following along and this thread was really helpful. I have a similar setup with RPi and Mesa 7c81 but I have 5-axis breakout board (HW356). This is how it looks like
.
I have selected "One Partport" in PNCconf but the parallel port options are very different from Stepconf. Could you please post a screenshot of parallel port configuration in pncconf for my breakout board. Thanks!

You should select a parallel port like interface in pncconf, not a parallel port
(I would suggest the G540 option)

I have the following settings:

Base Information
Axis configuration: XYZ with Include Spindle
Mesa0 PCI/ Etho/ Partport with "One Partport"

Mesa 0
Board Name: 5i25-Internal Data
Firmware: G540x2
Num of encoder: 0
Nim of PWM: 0
Num of step generators: 3

And I have used I/O connector 3 which you said will be P1 on Mesa7c81.

Sorry I couldn't understand what you meant by "parallel port like". I would really appreciate your help.

The G540 _is_ a parallel port like configuration

(as opposed to a more complex configuration for a breakout like a 7I76 or 7I77)

I guess I am still too dumb to understand. I have used G540 in firmware and edited in the hm2_pci to hm2_rpspi and hm2_5i25.0 to hm2_7c81.0 in .hal and .ini file. What should I do with the partport? Should I use "One Partport" or "None" in pncconf?

There is no parport so select "none"

Thanks for the help but there is still no movement. Here is what I have done so far.

Installed mesaflash from github.com/LinuxCNC/mesaflash
Downloaded 7c81_g540x2d.bit file from www.mesanet.com/software/parallel/7c81.zip
sudo mesaflash --device 7c81 --addr /dev/spidev0.0 --spi readhmid
sudo mesaflash --device 7c81 --addr /dev/spidev0.0 --write 7c81_g540x2d.bit
sudo mesaflash --device 7c81 --addr /dev/spidev0.0 --spi reload

Everything went fine but when I did the HALRUN, it gave errors that I couldn't understand. hm2_rpspi is probably not working and show pin is not showing anything

halrun
halcmd: loadrt hostmot2
Note: Using POSIX non-realtime
hm2: loading Mesa Hostmot2 driver version 0.15

halcmd: loadrt hm2_rpspi
rmmod: ERROR: ../libkmod/libkmod-module.c: 793 kmod_module_remove_module() could not remove 'spi_bcm2835': Operation not permitted
rmmod: ERROR: could not remove module 'spi_bcm2835': Operation not permitted
hm2_rpspi: ERROR: Failed to execute '/bin/rmmod spi_bcm2835'
hm2_rpspi: can't open /dev/mem
hm2_rpspi: cannot map peripheral memory
hm2_rpspi: rtapi_app_main: Permission denied (-13)
<stdin>:2: waitpid failed /home/pi/linuxcnc-dev/bin/rtapi_app hm2_rpspi
<stdin>:2: /home/pi/linuxcnc-dev/bin/rtapi_app exited without becoming ready
<stdin>:2: insmod for hm2_rpspi failed, returned -1

halcmd: show pin
Component Pins:

Owner Type Dir Value Name

I've connected the 5-axis breakout board with P1 of Mesa 7c81 and my jumper positions are also default on the mesa board. Also when I launch my configuration, there is a pop-up at the bottom right corner which says:

hm2/hm2_7c81.0: Watchdog has bit! (set the .has-bit pin to False to resume)

Kindly help in these regards