Playing with the XHC-HB04 driver

Let's play with the XHC-HB04 driver:
http://linuxcnc.org/docs/2.8/html/man/man1/xhc-hb04.1.html 
In one Terminal session:

muzzer@LinuxCNC:~$ halrun
halcmd: loadusr -W xhc-hb04 -H

(-W means to wait for the component to start up; -H means to specify HAL mode)

Then we see..

halcmd: xhc-hb04: waiting for XHC-HB04 device
xhc-hb04: found XHC-HB04 device

In a second Terminal window:

muzzer@LinuxCNC:~$ watch -n0.1 halcmd show pin xhc-hb04

the "-n0.1" option updates every 100ms. I don't see any mention of it in the docs but spotted it half way down in this forum thread. This is typical of LinuxCNC learning - you can't say it isn't documented somewhere but unless you are psychic or lucky, these options can pass you by.
This splurges out a list of the pins that have been created by the component (device?). This is encouraging.

But hold up, there's half the information missing, like the actual buttons. Of course, it needs to know where the config file is though - this tells it which buttons the pendant has. It's part of the std distribution and is kept at /usr/share/linuxcnc/hallib/xhc-hb04-layout2.cfg
So let's try again. The command line is getting a bit painful to type, especially if you fuck it up:

muzzer@LinuxCNC:~$ halrun
halcmd: loadusr -W xhc-hb04 -H -I /usr/share/linuxcnc/hallib/xhc-hb04-layout2.cfg

The -I option allows you to specify the path to the layout config file. The 18 button pendant is defined as "layout 2". Here's the content of the pendant layout file, xhc-hb04-layout2.cfg:

[XHC-HB04]
BUTTON=01:button-goto-zero
BUTTON=02:button-start-pause
BUTTON=03:button-rewind
BUTTON=04:button-probe-z
BUTTON=05:button-macro-3
BUTTON=06:button-half
BUTTON=07:button-zero
BUTTON=08:button-safe-z
BUTTON=09:button-home
BUTTON=0A:button-macro-1
BUTTON=0B:button-macro-2
BUTTON=0C:button-spindle
BUTTON=0D:button-step
BUTTON=0E:button-mode
BUTTON=0F:button-macro-6
BUTTON=10:button-macro-7
BUTTON=16:button-stop
BUTTON=17:button-reset
That's better. Now I can see all the buttons as well as all the pins:

So "all" I would have to do now is connect them up to my machine by rewriting the .hal file I've spent ages playing with. Bollocks.

Note that there are groups of 5 of some functions. For instance, pressing the "half" button will change the state of both xhc-hb04.button-half and xhc-hb04.button-half-x if the selector switch is set to the "x" position (the signal status changes in real time, subject to the update rate of 100ms here). Those x, y, z & a flavours are described as "synthesised" buttons, as they are formed by logical combination of the "half" button and the selector switch.

NB: An alternative command would be "halcmd show pin xhc-hb04", which takes a snapshot, rather than a live view. Somewhat better for copying and editing, perhaps. Like this:

muzzer@LinuxCNC:~$ halcmd show pin xhc-hb04

Component Pins:
Owner   Type  Dir         Value  Name
     4  float IN              0  xhc-hb04.a.pos-absolute
     4  float IN              0  xhc-hb04.a.pos-relative
     4  bit   OUT         FALSE  xhc-hb04.button-goto-zero
     4  bit   OUT         FALSE  xhc-hb04.button-goto-zero-a
     4  bit   OUT         FALSE  xhc-hb04.button-goto-zero-x
     4  bit   OUT         FALSE  xhc-hb04.button-goto-zero-y
     4  bit   OUT         FALSE  xhc-hb04.button-goto-zero-z
     4  bit   OUT         FALSE  xhc-hb04.button-half
     4  bit   OUT         FALSE  xhc-hb04.button-half-a
     4  bit   OUT         FALSE  xhc-hb04.button-half-x
     4  bit   OUT         FALSE  xhc-hb04.button-half-y
     4  bit   OUT         FALSE  xhc-hb04.button-half-z
     4  bit   OUT         FALSE  xhc-hb04.button-home
     4  bit   OUT         FALSE  xhc-hb04.button-macro-1
     4  bit   OUT         FALSE  xhc-hb04.button-macro-2
     4  bit   OUT         FALSE  xhc-hb04.button-macro-3
     4  bit   OUT         FALSE  xhc-hb04.button-macro-6
     4  bit   OUT         FALSE  xhc-hb04.button-macro-7
     4  bit   OUT         FALSE  xhc-hb04.button-mode
     4  bit   OUT         FALSE  xhc-hb04.button-probe-z
     4  bit   OUT         FALSE  xhc-hb04.button-reset
     4  bit   OUT         FALSE  xhc-hb04.button-rewind
     4  bit   OUT         FALSE  xhc-hb04.button-safe-z
     4  bit   OUT         FALSE  xhc-hb04.button-spindle
     4  bit   OUT         FALSE  xhc-hb04.button-start-pause
     4  bit   OUT         FALSE  xhc-hb04.button-step
     4  bit   OUT         FALSE  xhc-hb04.button-stop
     4  bit   OUT         FALSE  xhc-hb04.button-zero
     4  bit   OUT         FALSE  xhc-hb04.button-zero-a
     4  bit   OUT         FALSE  xhc-hb04.button-zero-x
     4  bit   OUT         FALSE  xhc-hb04.button-zero-y
     4  bit   OUT         FALSE  xhc-hb04.button-zero-z
     4  bit   OUT          TRUE  xhc-hb04.connected
     4  float IN              0  xhc-hb04.feed-override
     4  float IN              0  xhc-hb04.feed-value
     4  bit   IN          FALSE  xhc-hb04.inch-icon
     4  s32   OUT             0  xhc-hb04.jog.counts
     4  s32   OUT             0  xhc-hb04.jog.counts-neg
     4  bit   OUT         FALSE  xhc-hb04.jog.enable-a
     4  bit   OUT         FALSE  xhc-hb04.jog.enable-feed-override
     4  bit   OUT          TRUE  xhc-hb04.jog.enable-off
     4  bit   OUT         FALSE  xhc-hb04.jog.enable-spindle-override
     4  bit   OUT         FALSE  xhc-hb04.jog.enable-x
     4  bit   OUT         FALSE  xhc-hb04.jog.enable-y
     4  bit   OUT         FALSE  xhc-hb04.jog.enable-z
     4  float OUT             0  xhc-hb04.jog.increment
     4  float IN              0  xhc-hb04.jog.max-velocity
     4  bit   OUT         FALSE  xhc-hb04.jog.minus-a
     4  bit   OUT         FALSE  xhc-hb04.jog.minus-x
     4  bit   OUT         FALSE  xhc-hb04.jog.minus-y
     4  bit   OUT         FALSE  xhc-hb04.jog.minus-z
     4  bit   OUT         FALSE  xhc-hb04.jog.plus-a
     4  bit   OUT         FALSE  xhc-hb04.jog.plus-x
     4  bit   OUT         FALSE  xhc-hb04.jog.plus-y
     4  bit   OUT         FALSE  xhc-hb04.jog.plus-z
     4  float OUT         0.001  xhc-hb04.jog.scale
     4  float OUT             0  xhc-hb04.jog.velocity
     4  bit   OUT         FALSE  xhc-hb04.require_pendant
     4  bit   OUT          TRUE  xhc-hb04.sleeping
     4  float IN              0  xhc-hb04.spindle-override
     4  float IN              0  xhc-hb04.spindle-rps
     4  s32   OUT             1  xhc-hb04.stepsize
     4  bit   IN          FALSE  xhc-hb04.stepsize-down
     4  bit   IN          FALSE  xhc-hb04.stepsize-up
     4  float IN              0  xhc-hb04.x.pos-absolute
     4  float IN              0  xhc-hb04.x.pos-relative
     4  float IN              0  xhc-hb04.y.pos-absolute
     4  float IN              0  xhc-hb04.y.pos-relative
     4  float IN              0  xhc-hb04.z.pos-absolute
     4  float IN              0  xhc-hb04.z.pos-relative

Took a while to work out how to do that. But I don't plan to be using this pendant and driver anyway....