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Yeah std breakout board, a lot of the generic Chinese one have a 0-10v converter. Mesa also sells something called spinx1 store.mesanet.com/index.php?route=produc...oduct&product_id=205 which could be connected to the 2nd port on the 7i92T.
Glass sensor would require a buffer circuit of sorts I guess, PCW would have the best advice regarding that.

I've been using an original 7i92 for years (the change was to a different FPGA for the T) and had no issues........plus a number of other cards as things grew


This how good the support from Mesa is. Some users have bought clones from AliExpress (I'd recommend the genuine thing) and he's been happy to help those users out. TBH PCW has helped me out when I got bored and tried to build a clone of a 7c81 based on a Spartan6 FPGA dev board. Which does work either via SPI to Raspberry Pi 4/5 or a PC with a parallel port using the EPP protocol.

You may find some forum users very biased towards Mesa, some build machines professionally and only use Mesa, other have converted a mill or a lathe....or many other machines that I have probably missed. But they all swear by Mesa products.
Not that there aren't other options, but it's the best way if you "just wanna make chips".

Unfortunately, the situation is anything but simple… I reinstalled Bookworm, but the command:
`sudo mesaflash --spi --addr /dev/spidev0.0 --device 7c81 --readhmid`

doesn't work:

- open: No such file or directory
- No 7C81 board found

The following works:

`halcmd -kf`

`halcmd: loadrt hostmot2`

`halcmd: loadrt hm2_rpspi`

`halcmd: show all hm2`

However, I don't know how to write a new bitfile. That is, the equivalent of:

`sudo mesaflash --spi --addr /dev/spidev0.0 --device 7c81 --fallback --write bitfile-name`

I tried installing an older version of LinuxCNC – Buster. However, the libraries for installing mesaflash are missing and cannot be installed because the repositories for this version no longer exist.

7C81 configuration for 7I78 on P1, INM on first 12 P2 pins

The inm module supports up to 4 MPG encoders,
it also has built in input filtering/debouncing.

The last 5 P2 pins are left as GPIO so can be inputs/outputs
as needed


 

 

[/attachment]  I know that there is a configuration 7c81_7i78x2d.bit, but there is the same on P2 as on P1 - 7i78. Another 4 axes. And I don't need that for the lathe. But I would like one MPG encoder for each axis - basically to be able to control the lathe "almost" manually. The rest of P2 controls the tool turret and on P7 there are limit switches and buttons.
So that's the goal.

There is a 7I78X2 configuration: 7c81_7i78x2d.bit 

Do you need MPG encoders or high speed encoders+index?

Alternatively, could someone please create a bitfile for me for 7c81 with one 7i78 and port P2 entirely for encoders (i.e. at least 3)?

Hello, I was trying to change the bitfile in my 7c81 so that there would be only one 7i78 on port P1. Port P2 would be freed up for separate MPGs for X and Z axes. So there would be no need for 7i33 (which would probably be another complication I wouldn't go through). But in the Mesa firmware there is no 7i78x2 configuration, nor 7i78 for Xilinx ISE (*.xise). Is it possible to download this configuration somewhere else?

I suggested the G540 configuration because it includes  PWM generator that you can use
with pncconf for setting up the the spindle, the 7I76 configuration does not.

On the halcmd, yes you need the driver loaded, as I mentioned:

Note that you can list all pin and parameter names when LinuxCNC is running with:

ENCA+, ENCA-, ENCB+, ENCB-, IDX+, IDX- are all physical signal names and are not present in hal

encoder hal pins and parameters will all have names like:

hm2_7c81.0.encoder.00.position
hm2_7c81.0.encoder.00.index-enable
 etc etc

Where  the 00 in hm2_7c81.0.encoder.00.position is the encoder number

with 7C81 7i78X2d or 7I78x3d firmware, encoder 0 would be on P1

If you want to use encoder 0 on P1 for the spindle encoder, you select encoder 0
as spindle encoder  in pncconf. Similarly PWMgen 0 is on P1 with the 7I78 firmware
so pwmgen 0 would be selected for spindle speed control.





 

Thanks for the answer. There is one 7i78 -> P1 connected to 7c81, one optocoupler board on P7 and when I know how to do it, one 7i73. Why not pncconf for 7i76 but G540? It's more similar to 7i78. So with that encoder it means that it doesn't matter where and what encoder I choose, just change the name in .hal according to your example? Sorry for the question, will it be clear that it is a spindle encoder? Although it may be a stupid question, 7i78 has only one encoder and it is for the spindle... In the manual for 7c81 the encoder is marked as ENCA+, ENCA-, ENCB+, ENCB-, IDX+, IDX-. I don't know how it will look in .hal, because pncconf does not have the option to configure the 7c81 board. Well, with the list of parameters, it's clear, but as I already wrote, I'm completely lost and it's going slowly .

Whats actual hardware do you have?

It sounds like a 7C81 and one 7I78.

It that case is might be simpler to use something like a pncconf 5i25/G540 configuration
as a starting point as that would al least let you setup the PWM spindle in pncconf.

In general, if you have the correct firmware for the daughtercard, the pins don't matter
in the hal files, what is significant is the module number like stepgen 0,1,2,3, etc.
The exception is GPIO pins.

The 7I78 encoder pins will have names like hm2_7c81.0.encoder.00.position.
7I73 MPG encoders will have names like hm2_7c81.0.7i73.0.0.enc0.position

Note that you can list all pin and parameter names when LinuxCNC is running with:

halcmd show all hm2





 

Hi All,

I am using 7c81 board, raspi 5 with thc proma 150. I am using QTplasmaC 
The gpios and leds for UP, DOWN, Arc OK are getting connected and blinking.
However, the Auto Z axis movement not happening with thc proma 150. Attaching the files for your reference. Please help.

Hello. I would like to advise how to change the configuration files (I assume it concerns .hal and .ini) generated by the pncconfig program for 7i76. Linuxcnc is installed on 7c81 and the firmware is for two 7i78. Two axes for the lathe and most of the necessary switches are without problems. However, I need control of the main spindle and input from the incremental encoder for the spindle and a serial port for the 7i73 handwheel and possibly additional buttons.
I apologize for the possibly trivial question. But I had a break from using Linuxcnc for several years and I simply forgot a lot of things, not to mention that many things were never completely clear to me.Now that I'm retired, I finally have enough time for all of this, but unfortunately, it's too complex for me.

Sold.

I know that with the mesa 7c81 boards it is recommended to have a length of less than ~2.5" for the SPI cable length. So it just maybe the cable length is too long.
Dupont cables aren't ideal for SPI transmission at speed.
So ideas to try.
Ribbon cable with every second conductor a ground terminated at one end only, of course you will need a dedicated return ground. This may involved a custom bit of PCB at each end.
Shorter cable length for sure.
There's some other fixes I was going to suggest, but since the remora bards are "all in one" they would not apply.
But I guess a quality PSU, think Meanwell, might be worth considering.
My first port of call would be to reduce the SPI cable to the absolute minimum, preferably to under 2.5" max.
One thing of note is that I have the RPi5 can tolerate a longer SPI cable that the RPi4, the caveat being this is based on experience with a home made 7c81 clone.
I'm apologise if the references to the 7c81 is annoying, but it is entirely based on my experience with SPI as a communication medium. I honestly hope that some of the above suggestions will give you good for thought.

forum.linuxcnc.org/27-driver-boards/3889...7c81?start=20#195102