METRIC / SAE Indicator for pyVCP

Askjerry
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9 years 11 months ago #83326 by Askjerry

METRIC / SAE Indicator for pyVCP was created by Askjerry

Is there some kind of a hal pin that I can look at and point to a graphic so that I have a quick indication if the machine is in SAE or METRIC mode?

I want to make a pyVCP graphic... yellow with "METRIC" or blue with "INCH" that is pretty easy to see... I know how to make graphos. net them... etc... just looking for something like halui.mode.is-mm or similar that will give me a true/false.

Exists???

Jerry

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Todd Zuercher
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9 years 11 months ago #83342 by Todd Zuercher

Replied by Todd Zuercher on topic METRIC / SAE Indicator for pyVCP

No there isn't a hal pin that I know of. If you use a GladeVCP though it is fairly simple to uses a Linuxcnc Stat object to get it. Another option would be a custom hal component to get it.

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Askjerry
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9 years 11 months ago #83345 by Askjerry

Replied by Askjerry on topic METRIC / SAE Indicator for pyVCP

Yeah... I haven't figured out custom HAL yet... I know there is a list of active G-Codes shown in the MDI section... if I could find out where that variable was and look for G20 or G21... but I don't have the time to dig into that quite yet. I was looking for a quick indicator... guess it's going to turn into a "project" instead.

Thanks,
Jerry

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screwtop
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9 years 11 months ago #83386 by screwtop

Replied by screwtop on topic METRIC / SAE Indicator for pyVCP

Interesting question. I found a couple of pertinent global variables, but don't know that you can access these from pyVCP:

Code:

#<_metric> - Return 1 if G21 is on, else 0.
#<_imperial> - Return 1 if G20 is on, else 0.

I had a rummage around in the source and couldn't find a HAL pin for this. It would be useful, though, and I think probably should exist for completeness. I found the following possibly useful leads in src/emc/task/emccanon.cc:

Code:

emcStatus->task.programUnits
emcStatus->motion.traj.linearUnits

and also in src/emc/usr_intf/axis/extensions/emcmodule.cc:

Code:

    {(char*)"linear_units", T_DOUBLE, O(motion.traj.linearUnits), READONLY},

I haven't written a custom HAL component either, but maybe this would be a good one to start with...

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screwtop
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9 years 11 months ago #83387 by screwtop

Replied by screwtop on topic METRIC / SAE Indicator for pyVCP

Also, it seems it's not just a question of mm or inches: in places the code has support for mm, cm, inches, custom, and auto! But the core EMC code seems to be limited to mm, cm or inches for the canonical units; this from src/emc/nml_intf/canon.hh:

Code:

typedef int CANON_UNITS;
#define CANON_UNITS_INCHES 1
#define CANON_UNITS_MM 2
#define CANON_UNITS_CM 3

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cmorley
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9 years 11 months ago - 9 years 11 months ago #83389 by cmorley

Replied by cmorley on topic METRIC / SAE Indicator for pyVCP

Here is working sample code of a python component for metric (G20/21) status
The python component info is somewhat explained here:
www.linuxcnc.org/docs/2.7/html/hal/halmodule.html
name it metric_status , add it into an appropriate folder ($PATH in a terminal should show you)
and make it executable

One caveat, displayed Gode in a running linuxcnc program, can be wrong because of read ahead.
This one is fairly safe as not too many people change the units mid program.

Code:

#!/usr/bin/env python
import linuxcnc
import hal,time

metric = False

h = hal.component("metric_status")
h.newpin("out", hal.HAL_FLOAT, hal.HAL_OUT)
h.ready()

status = linuxcnc.stat()
try:
    while 1:
        # update once a second
        time.sleep(1)
        # poll current status
        status.poll()
        # search active G codes
        # only check whole numbered Gcodes
        for i in sorted(status.gcodes[1:]):
            if i == -1: continue
            if i % 10 == 0:
                if i == 210:
                    metric = True
                    break
                elif i == 200:
                    metric = False
                    break
        # Update pin
        h['out'] = metric
except KeyboardInterrupt:
    raise SystemExit

Hope that helps!
Chris M

Last edit: 9 years 11 months ago by cmorley.

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METRIC / SAE Indicator for pyVCP