Advanced Search

Hi Friends,

Sorry i probably elaborate enough. My goal is to reduce the error in my C/A axis. Currently it jogs, but its shaky and based on what i've seen tuning the servo could help this.

I am reasonably confident in my step and encoder scale figures - 90 deg turn looks like a 90 deg turn. The main issue i am having is that i can't for the life of me find any of the encoder pins that i should be using to tune in HalScope. I know that the tutorial is for a different board but i imagine they would have similar names? i am using 7i96s, below is a screen shot of halwatch when i search for the work "analog". Most of the highlighted ones seem to be inputs, e.g. when i put them in the scope i can enter a value for them. the only ones that seemed to be outputs are in the photo and do no change when i jog the C axis

any advice is greatly appreciated

What should I do to not kill my board?

www.sainsmart.com/products/cnc-5-axis-br...stepper-motor-driver
 Is the common breakout I recommend.

You can connect directly to the parallel expansion connector but one wiring mistake
and you may kill the 7I97T

You can check the (DB25) pinout with mesaflash's --readhmid command if you have loaded the
desired firmware into the 7I97T.  You can also check the .pin files in the 7I97t.zip support image.
These are just the result of running mesaflash with the --readhmid option on a 7I97T with the
corresponding firmware loaded.

If you download the latest mesaflash, it has the option of showing the HDR26 pinout (the normal default
is to show the DB25 pinout)

What also helps if you give an overview of your complete project, rather than just a little bit at a time.
If you just want to run a single stepper Linuxcnc may be overkill, operating the parallel port via a simple C program may be easier, but that will mean obtaining permissions from the kernel to do these, and running in user space may not give consistent timings for the stepper.
The other option would be to have a hardware base approach and use python or what ever to control when the stepper runs & stops.
Even a simple Arduino sketch controlled by via a serial connection would be easy. Depending on the library used you could have control over decel & accel.

Hardware RPi 5 8gb
IMAGE rpi-5-debian-bookworm-6.12.11-arm64-ext4-2025-01-27-0140 (1).img.xz

On a fresh image install i get failure to start service in the boot.log below is from the journalctl

i formatted and tried again same problem any ideas?Feb 20 14:49:54 raspberrypi systemd[1]: Starting zramswap.service - Linux zramswap setup...
░░ Subject: A start job for unit zramswap.service has begun execution
░░ Defined-By: systemd
░░ Support: www.debian.org/support
░░
░░ A start job for unit zramswap.service has begun execution.
░░
░░ The job identifier is 119.
Feb 20 14:49:54 raspberrypi root[738]: Starting Zram
Feb 20 14:49:54 raspberrypi zramswap[738]: <13>Feb 20 14:49:54 root: Starting Zram
Feb 20 14:49:54 raspberrypi zramswap[734]: /usr/sbin/zramswap: line 53: echo: write error: Invalid argument
Feb 20 14:49:54 raspberrypi systemd[1]: zramswap.service: Main process exited, code=exited, status=1/FAILURE
░░ Subject: Unit process exited
░░ Defined-By: systemd
░░ Support: www.debian.org/support
░░
░░ An ExecStart= process belonging to unit zramswap.service has exited.
░░
░░ The process' exit code is 'exited' and its exit status is 1.
Feb 20 14:49:54 raspberrypi systemd[1]: zramswap.service: Failed with result 'exit-code'.
░░ Subject: Unit failed
░░ Defined-By: systemd
░░ Support: www.debian.org/support
░░
░░ The unit zramswap.service has entered the 'failed' state with result 'exit-code'.
Feb 20 14:49:54 raspberrypi systemd[1]: Failed to start zramswap.service - Linux zramswap setup.
░░ Subject: A start job for unit zramswap.service has failed
░░ Defined-By: systemd
░░ Support: www.debian.org/support
░░
░░ A start job for unit zramswap.service has finished with a failure.
░░
░░ The job identifier is 119 and the job result is failed.

Most likely a loose connection or bounce. maybe use debounce?

There is a way to do it in Hal, run a search on the forum for an example. I don't have one handy to share,. But it was xor component used I think from memory. Or maybe someone has something setup they can share.

That instruction is in the docs.

kcjengr.github.io/probe_basic/machine_config.html

the pinout or configuration to connect the step and dir where could I find it?

pata = Parallel ATA or the old hard drive comms, not used since .... long ago
If you are using an normal IDE hard drive, not much you can except maybe changing the IRQ number in BIOS, although some boards might now allow it.
If you are not using IDE, then disabling them in BIOS might just be possible.
Mind you, almost all SATA controllers can emulate PATA, so if your SSD is not set to AHCI, disabling IDE is not possible, but setting the SATA to AHCI in BIOS should remove PATA showing and using an IRQ.

the breackout board need protection?

thank you for you answer

tommylight wrote:

You can just wire drives directly to IDC26, but that does require caution in proper wiring as those I/O pins are highly sensitive.

This means no BOB.

Actually I found a mistake in my grub command line.  Now my histogram is better, in that there are only a few excursions to debug now. 
 

It looks like only interrupt that seems to fire at roughly the same frequency is IRQ 20 which is described as

IO-APIC 20-fasteoi pata_pdc2027x[0000:03.05.0]

It is interesting that it fires on CPU1.  I thought I had a command in my grub setup to disable hyperthreading.
 

Fair enough. I thought I had gone through all the steps but I guess I missed it.

I just got a touch probe and want to set it up alongside my tool height setter.

Turns out the tool height setter I bought years ago is NC.
Without even thinking about checking I bought a NO probe which if I am thinking about it correctly if I wanted to wire them into the same pin it would have to be NO.

From what I can tell in reading though it seems like I should be able to wire them into separate pins on my 7i76e, distinguish one as NO, the other as NC, and get it to function properly correct?

And from reading it does sound like LinuxCNC still only has one probe function right? So in the configs I tie both sensors/pins to the single probe function correct?

That is going to be it. I'll make the change and check in the morning.