Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
Category: Software
General-purpose computers doing something specific
This useful comment thread showed up in relation to a post about a chainsaw repair, which would hide it from any rational collection of search terms. Here’s the thread in all its glory, as there doesn’t seem to be a way to move comments from one post to another.
Feel free to continue the topic in the comments to this post…
randomdreams
Offtopic: have you ever used gEDA for schematic or pcb? I’m looking for something with reasonable abilities, and the crippled demo versions of orcad, eagle, and winqcad all look fairly crippled. I’ve zero use for autorouters and autoplacers (because they suck for analog design) but it’d be nice to have something that’s fairly usable for schematic and layout.
Ed
used gEDA for schematic or pcb?
Nope. Every time I’ve looked at it, the status seems to be heartbreakingly close to being useful by someone who really doesn’t want to work around a morass of limitations. That’s becoming less true and maybe by now it’s practical… but I haven’t done a serious examination for maybe a year.
I actually coughed up half a kilobuck for the Standard version of Eagle schematic & layout, as an autorouter doesn’t do much for the little bitty boards I build. Works fine, no complaints, but if I weren’t doing columns and suchlike, it’d be hard to justify.
It is quite usable, but the version that ships with most linux distros is pretty old, I had much better luck building it from source following the instructions on the gEDA homepage. The hardest part is creating symbols for the PCB tool, that is a little tricky to learn, but there are a lot of them pre-created for you on gedasymbols.org.
randomdreams
Thanks to both of you. I’ll probably give it a run. I currently spend much of my day creating symbols for Cadence, and I consider it impossible for any other part-creation process to be as painful or difficult as that. I’m more worried about general usability. Eagle’s the back-up plan.
John Rehwinkel
I still haven’t found a PCB layout program I like (and I’ve gotten tired of the truly primitive one I wrote 20 years ago). For schematics, I use DesignWorks Lite, which is apparently no longer offered (though DesignWorks Professional is still available).
John Rehwinkel
Ah, it is still offered (only $40), just not at the main Capilano site. The companion PCB layout program is Osmond ($200), which I keep meaning to try out. You can download the trial version at designworks4.com.
I have an X10 CM11A “Two Way Computer Interface” handling the very very very few scheduled events for our house. Basically, it turns the living room lights on in the evening and everything off much later.
As a result, I tend to ignore it for years at a time. A recent power outage killed the regularly scheduled events, which suggested that the backup batteries needed changing… and, yes, they were pretty well corroded.
With that out of the way, I discovered that the last time I’d loaded a program into the thing was so long ago that the heyu config files had either gone missing or were on a system not near the top of my heap. It’s easy enough to configure, so I installed heyu and spun up a new set of config files.
All the doc I can find says the CM11A has an RJ11 modular phone jack, which mates with the standard 6-position 4-conductor dingus found on the end of every phone in this part of the world. My CM11A, however, has a 4P4C jack, the narrower dingus found on phone handsets. Given that heyu reports
Firmware revision Level = 1
I suspect that this thing is slightly older than some of the folks reading this post and the X10 factory switched to a somewhat less bizarre connector in mid-stream.
Anyhow, the DB9 (yeah, it’s a DE9, but nobody calls it that) connector has “X10 Active Home” printed on it in my very own handwriting, with a standard RJ11 plug on the end. A double-jack adapter connects a hank of cable with an RJ11 plug on one end and a 4P4C connector on the other. I have no idea where that cable came from; perhaps I replaced the 4P4C plug with something less bizarre to add that extension so the cable would stretch from PC to wall outlet?
I plugged the thing into a USB-RS232 adapter and heyu had no trouble talking to the CM11A. However, trying to execute
heyu dim n13 10
produced the discouraging report
RI serial line may be stuck.
A bit of deft multimeter work produced this pinout list, which agrees with most of the doc you’ll find elsewhere. Hold the 4P4C connector with the tab down and the cable away from you: the pin numbers are 4 3 2 1 from left to right. The RS-232 pins are printed right on the DB-9 connector.
4P4C DB9
1 2 RxD
2 9 RI
3 3 TxD
4 5 Gnd
It’s entirely possible the USB converter doesn’t support RI or it doesn’t do a good job of it. I jammed the cable into the serial port on the back of the PC and shazam it works perfectly.
The x10.conf file, for the next time around
TTY /dev/ttyS0
HOUSECODE N
LATITUDE 41:40N
LONGITUDE 73:53W
ALIAS MBR_Dresser N1
ALIAS Front_Hall N5
ALIAS RV_XCVR N9
ALIAS Couch N10
ALIAS Mary_Reading N11
ALIAS LR_Ceiling N12
ALIAS Fireplace N13
ALIAS Kitchen N14
ALIAS Patio N15
ALIAS Garage_Spots N16
START_ENGINE AUTO
LOG_DIR /var/log/heyu/
DATE_FORMAT YMD '-'
Nothing like sleeping on a problem. It turns out that a chunk of HAL code can do a nice job of locking out an inactive joystick axis.
The general idea:
A priority encoder selects one axis when both go active simultaneously
The prioritized outputs set flipflops that remember the active axis
The active axis locks out the other one until they’re both inactive
That way, you can start to jog either axis on a knob without worrying about accidentally jogging the other axis by moving the knob at a slight diagonal. I hate it when that happens.
The other tweak is that the quartet of buttons on the right act as a “hat” for the Z and A axes, jogging them at the current maximum speed.
Because it’s tough to accidentally push two buttons at once, there’s no need to lock them out. So you can jog diagonally by deliberately pushing adjoining buttons, but you must want to do that.
Rather than dumping the whole program again, here are the key parts…
Figuring out if a joystick axis is active uses the window comparators. It seems the idle counts value varies slightly around 127, so I relaxed the window limits. Should the window comparator go active with the knob centered, the buttons for that axis won’t produce any motion.
net x-jog-count-int input.0.abs-x-counts conv-s32-float.0.in
net x-jog-count-raw conv-s32-float.0.out wcomp.0.in
setp wcomp.0.min 125
setp wcomp.0.max 130
net X-inactive wcomp.0.out not.0.in
net X-active not.0.out
The priority encoder is just a gate that prevents Y (or A) from being selected if X (or Z) is simultaneously active. Here’s a sketch for the ZA knob:
Axis priority encoder
The active and inactive signals come from the window detectors. The sketch gives the K-map layout, although there’s not a whole lot of optimization required.
The corresponding code:
net Z-inactive and2.5.in0
net A-active and2.5.in1
net A-select and2.5.out # select A only when Z inactive
net Z-inactive and2.6.in0
net A-inactive and2.6.in1
net ZA-Deselect and2.6.out # reset flipflops when both inactive
net Z-active and2.7.in0 # set Z gate when knob is active
net A-gate-not and2.7.in1 # and A is not already gated
net Z-set and2.7.out flipflop.2.set
net ZA-Deselect flipflop.2.reset # reset when neither is active
net Z-gate flipflop.2.out not.6.in
net Z-gate-not not.6.out
net A-select and2.8.in0 # set A gate when knob is active
net Z-gate-not and2.8.in1 # and Z is not already gated
net A-set and2.8.out flipflop.3.set
net ZA-Deselect flipflop.3.reset # reset flipflop when both inactive
net A-gate flipflop.3.out not.7.in
net A-gate-not not.7.out
The flipflops remember which axis went active first and lock out the other one. When both axes on a knob return to center, the flipflops reset.
The quartet of buttons produce binary outputs, rather than the floats from the Hat, so a pair of multiplexers emit -1.0, 0.0, or +1.0, depending on the state of the buttons, for each axis.
setp mux2.6.in0 0.0
setp mux2.6.in1 -1.0
net A-btn-neg input.0.btn-trigger mux2.6.sel
net A-btn-neg-value mux2.6.out sum2.1.in0
setp mux2.7.in0 0.0
setp mux2.7.in1 1.0
net A-btn-pos input.0.btn-thumb2 mux2.7.sel
net A-btn-pos-value mux2.7.out sum2.1.in1
net A-jog-button sum2.1.out
net A-btn-neg or2.1.in0
net A-btn-pos or2.1.in1
net A-btn-any or2.1.out or2.2.in0
net A-gate or2.2.in1
net A-motion or2.2.out
The A-motion signal is true when either of the A jog buttons or the A joystick axis is active. That gates the MAX_ANGULAR_VELOCITY value to halui.jog-speed, rather than the default MAX_LINEAR_VELOCITY. Or, depending on the state of the toggle from the two joystick push switches, 5% of that maximum. A mere 5% may be too slow for the A axis, but it’ll take some experience to determine that.
With that in hand, the final step is gating either the knob or the button values to halui.jog.*.analog.
net Z-jog-button mux2.8.in0
net Z-jog-knob-inv mux2.8.in1
net Z-gate mux2.8.sel
net Z-jog mux2.8.out halui.jog.2.analog
net A-jog-button mux2.9.in0
net A-jog-knob input.0.abs-z-position mux2.9.in1
net A-gate mux2.9.sel
net A-jog mux2.9.out halui.jog.3.analog
The Hat jogs X and Y at the current maximum speed.
The Left Knob jogs X and Y proportionally to the Knob displacement.
The Right Knob jogs Z (Up-Down) and A (Left-Right) proportionally to the Knob displacement.
Press either Knob downward to toggle the maximum jog speed between MAX_LINEAR_VELOCITY (as defined in the Sherline.ini file) and 5% of that value. The slow speed is useful for creeping up on alignment points: the first active level of the joysticks runs at a nose-pickin’ pace.
The left little button (labeled 9) switches to Manual mode, although the AXIS display does not update to indicate this. Same as “F3” on keyboard, minus the GUI update.
The right little button (labeled 10) continues a G-Code program by activating the Resume function. Same as “S” on the keyboard.
The Mode button switches the functions of the Hat and Left Knob. That button does not generate an output and the Mode cannot be controlled programmatically. Swapping those functions doesn’t seem particularly useful in this application, so the LED should never be ON.
Buttons 1-4 are not used for anything yet.
On the back:
Pressing the left-hand pair of buttons (labeled 5 and 7) activates E-stop. Yes, I know all about why you shouldn’t have E-stop run through software. This is a Sherline mill. Work with me here.
The right-hand buttons (labeled 6 and 8) do nothing yet.
The code…
In Sherline.ini:
[HAL]
HALUI=halui
In custom.hal:
loadusr -W hal_input -KA Dual
All the heavy lifting happens in custom_postgui.hal. As nearly as I can tell, HAL is basically a write-only language, so there’s block diagram of the major chunks of “circuitry” down at the bottom.
First, some setup and the simple buttons:
#--------------
# Logitech Dual Action joypad
loadrt and2 count=3
loadrt conv_s32_float count=3
loadrt mux2 count=2
loadrt or2 count=1
loadrt scale count=4
loadrt sum2 count=2
loadrt toggle count=1
loadrt wcomp count=3
#-- central buttons activate manual mode and restart the program
net mode-manual input.0.btn-base3 halui.mode.manual
net pgm-resume input.0.btn-base4 halui.program.resume
#-- left-hand rear buttons active estop
addf and2.0 servo-thread
net pgm-estop-0 input.0.btn-base and2.0.in0
net pgm-estop-1 input.0.btn-top2 and2.0.in1
net pgm-estop and2.0.out halui.estop.activate
Because the Left Knob and Hat will never be active at the same time, a sum2 block combines the two controls into single value (separate for X and Y, of course). Each sum2 input has a separate gain setting, which is a convenient place to adjust the Y axis sign.
#-- left knob runs XY at variable rate
# hat runs XY at full throttle
addf sum2.0 servo-thread
net x-jog-knob input.0.abs-x-position sum2.0.in0
setp sum2.0.gain0 +1.0
net x-jog-hat input.0.abs-hat0x-position sum2.0.in1
setp sum2.0.gain1 +1.0
net x-jog-total sum2.0.out halui.jog.0.analog
addf sum2.1 servo-thread
net y-jog-knob input.0.abs-y-position sum2.1.in0
setp sum2.1.gain0 -1.0
net y-jog-hat input.0.abs-hat0y-position sum2.1.in1
setp sum2.1.gain1 -1.0
net y-jog-total sum2.1.out halui.jog.1.analog
The Right Knob values go through scale blocks to adjust the polarity. Note that the Gamepad’s rz axis controls the EMC2 Z axis and Gamepad z controls the EMC2 A axis. Basically, it made more sense to have up-down control Z and left-right control A.
#-- right knob runs Z at variable rate (front-back)
# A (left-right)
addf scale.0 servo-thread
net z-jog-knob input.0.abs-rz-position scale.0.in
setp scale.0.gain -1
net z-jog-total scale.0.out halui.jog.2.analog
addf scale.1 servo-thread
net a-jog-knob input.0.abs-z-position scale.1.in
setp scale.1.gain +1
net a-jog-total scale.1.out halui.jog.3.analog
There’s only a single halui.jog-speed setting, but the jog speeds for the linear axes and the angular axes differ by so much that Something Had To Be Done. As above, I assumed that only one of the axes would be jogging at any one time, so I could set halui.jog-speed to match the active axis.
A window comparator on each linear axis detects when the joystick is off-center; the output is 1 when the axis is centered and 0 when it’s pushed. Combining those three signals with and2 gates gives a combined linear-inactive signal.
A mux2 block selects the MAX_ANGULAR_VELOCITY from the ini file when linear-inactive = 1 (linear not active) and MAX_LINEAR_VELOCITY when it is 0 (any linear axis off-center).
Done that way, rather than detecting when the angular axis is off-center, means that inadvertently activating the angular axis during a linear jog doesn’t suddenly boost the linear speed. Given that the max linear is about 28 inch/minute and the max angular is 2700 degree/min, it’s a pretty abrupt change.
I’m thinking about adding + shaped gates to at least the Right Knob so I can’t inadvertently activate both Z and A. I’m sure there’s a HAL lashup to do the same thing, though.
#-- set jog speed by toggle from either knob button
# press any knob button to toggle
addf and2.1 servo-thread
addf and2.2 servo-thread
addf conv-s32-float.0 servo-thread
addf conv-s32-float.1 servo-thread
addf conv-s32-float.2 servo-thread
addf mux2.0 servo-thread
addf mux2.1 servo-thread
addf or2.0 servo-thread
addf scale.2 servo-thread
addf scale.3 servo-thread
addf toggle.0 servo-thread
addf wcomp.0 servo-thread
addf wcomp.1 servo-thread
addf wcomp.2 servo-thread
#-- determine if any linear knob axis is active
net x-jog-count-int input.0.abs-x-counts conv-s32-float.0.in
net x-jog-count-raw conv-s32-float.0.out wcomp.0.in
setp wcomp.0.min 126
setp wcomp.0.max 128
net x-jog-inactive wcomp.0.out and2.1.in0
net y-jog-count-int input.0.abs-y-counts conv-s32-float.1.in
net y-jog-count-raw conv-s32-float.1.out wcomp.1.in
setp wcomp.1.min 126
setp wcomp.1.max 128
net y-jog-inactive wcomp.1.out and2.1.in1
net xy-active and2.1.out and2.2.in0
net rz-jog-count-int input.0.abs-rz-counts conv-s32-float.2.in
net rz-jog-count-raw conv-s32-float.2.out wcomp.2.in
setp wcomp.2.min 126
setp wcomp.2.max 128
net z-jog-inactive wcomp.2.out and2.2.in1
#-- convert ini file unit/sec to unit/min and scale for slow jog
setp mux2.0.in0 [TRAJ]MAX_LINEAR_VELOCITY
setp mux2.0.in1 [TRAJ]MAX_ANGULAR_VELOCITY
net linear-inactive and2.2.out mux2.0.sel
The ini file velocities are in units/second, so a scale block multiplies by 60 to get units/minute.
Another scale block multiplies by 0.05 to get slow-speed jogging. Obviously, that value is a matter of taste: tune for best picture.
Those two values go into a mux2 driven by the output of a toggle triggered by the or2 of the two buttons under the Knobs. Pushing either Knob down flips the toggle.
setp scale.2.gain 60
net jog-per-sec mux2.0.out scale.2.in
net jog-per-min scale.2.out mux2.1.in0
net jog-per-min scale.3.in
setp scale.3.gain 0.05
net jog-per-min-slow scale.3.out mux2.1.in1
net xy-button input.0.btn-base5 or2.0.in0
net za-button input.0.btn-base6 or2.0.in1
net xyza-button or2.0.out toggle.0.in
net xyza-slowmode toggle.0.out mux2.1.sel
net axis-jog-speed mux2.1.out halui.jog-speed
When the jog speed is at the maximum allowed, it still gets trimmed by the per-axis limits, so you can’t over-rev the motors no matter how hard you try. Even better, changing the values in the ini file automagically affect the gamepad jog speeds.
Here are the pin names for a Logitech Dual Action USB (wired) gamepad, according to EMC2 2.3.4. You’ll need these to wire it up as a control pendant for your EMC2 CNC milling machine…
There’s no need for -KRAL because it has no programmable LEDs.
Prefix all these with input.0. to get the complete name.
Hat Left-Right
abs-hat0x-counts
abs-hat0x-position
Hat Up-Down
abs-hat0y-counts
abs-hat0y-position
Hat Push
none
Left Knob Left-Right
abs-x-counts
abs-x-position
Left Knob Up-Down
abs-y-counts
abs-y-position
Left Knob Push
btn-base5
Right Knob Left-Right
abs-z-counts
abs-z-position
Right Knob Up-Down
abs-rz-counts
abs-rz-position
Right Knob Push
btn-base6
Button 1
btn-trigger
Button 2
btn-thumb
Button 3
btn-thumb2
Button 4
btn-top
Button 5
btn-top2
Button 6
btn-pinkie
Button 7
btn-base
Button 8
btn-base2
Button 9
btn-base3
Button 10
btn-base4
Mode button
swap Hat & Left Knob
lights red LED
All of the buttons have -not output pins.
The Knob position values run from -1.0 to +1.0 (float) and rest (almost) at 0.0 when centered. Their counts (s32) run from 0 to 255 and rest at 127 when centered.
The Hat button position values are only -1.0 and +1.0, centered at 0.0. The counts are only -1 and +1, with 0 when un-pushed. Although they take on only integer values, the position values are floats.
Both Knobs and the Hat have -Y position values at the top and +Y values at the bottom, exactly backwards from what you want. Expect to reverse the Y axis sign when you write the HAL code.
The -X position values are to the left, where you want them.
Although there’s a tactile click when pushing the Hat straight down, there is no corresponding button output. I don’t know if this is an oversight in the HAL interface or if there’s no actual switch in there.
The Mode button swaps the Hat and Left Knob functions. With the red LED on, both the Hat and Knob axes produce only -1 and +1 position and counts values.
A guide to figuring this stuff out is there, with useful pointers elsewhere on the main doc page.
So I signed into the credit union’s online banking site, did the multi-factor authentication dance, and was confronted with this dialog box…
HVFCU Mystery DLL Download
No, as a matter of fact, I did not choose to open ibank.dll, thank you very much for asking.
Well, what would you do?
Got this response from the credit union’s email help desk:
Upon speaking to out Information Technology department, I have been advised that this is a known problem for FireFox, Mac, and Linux users.
Hmmm, well now, Internet Explorer is conspicuous by its absence on that list, isn’t it?
A bit more prodding produced this response:
HVFCU uses a third party vendor to provide the Internet Banking software used on our servers. On November 22 we installed the equivalent of their year end release (which is mandatory due to regulatory changes contained in the release). Subsequent to that upgrade we discovered that errors had been introduced for Mac and/or Linux users of Safari and FireFox (and also for a small subset of Windows Internet Explorer users). These same errors do not occur on Safari nor FireFox running on Windows. We reported these problems to our vendor within 24 hours of the installation.
My guess is that the “small subset of Windows Internet Explorer users” corresponds to the few who actually armored-up their IE security settings enough that it doesn’t automatically download and execute anything offered to it from any website.
The rest, well, those PCs are most likely part of a zombie botnet.
He assured me:
The “ibank.dll” program cannot run on a Mac nor a PC. It is solely a server side application which generates HTML pages.
Just guessing here, but if the “misconfiguration” had extended to actually serving the file, well, it probably would have run just fine (or, at least, attempted to run) on any Windows PC. They are, after all, using DLLs on the server, so it’s not like they’re a Unix-based shop.
And it’s pretty obvious that their vendor’s testing extended only far enough to verify that the code worked with security settings dialed to “Root me!” Maybe they didn’t actually do any testing at all; this was, after all, just an end-of-year update. What could possibly go wrong?
If you’re wondering why your Windows-based PC has been behaving oddly, maybe you’ve gotten a drive-by download from a trustworthy site with all the appropriate icons on their home page.
Makes you really trust the banking system, doesn’t it?
Or maybe it’s just another reason to stop using Windows…
Again, this is similar to the FDI file for Xubuntu, with a partial match on the name.
The button mapping swaps the two buttons along the pen, leaving the tip as Button 1. Button 2 pops up context menus, which I find easier when it’s on the front part of that two-button rocker.
X occasionally crashes hard when the tablet moves the pointer between the two screens. It’s more common when scrolling, where the pointer is moving vertically along the gutter and falls off the edge. The workaround: restrict the tablet pointer so that it can’t quite get off the edge of the screen. Setting the BottomX value to just slightly more than the tablet can produce seems to work well: Tablet max = 16704 and BottomX = 16750.
Unlike in Xubuntu, the tablet values mapped pretty closely to the whole screen; there was no need for absurd scaling values to expand a small upper-left rectangle to the full screen.
The problem with hard X crashes is that X takes the (USB) keyboard down with it. The only solution seems to be ssh-ing in from another system and killing startx; you cannot Ctrl-Alt-Backspace or Ctrl-Alt-F1 or any of that stuff with a completely dead keyboard.
You must include the SendCoreEvents option, otherwise The GIMP (and, presumably, other tablet-aware apps) will capture the events and never relinquish focus to system dialog boxes. Like, for example, the tablet won’t be able to focus inside the File->Save As dialog box…
Herewith, the file /etc/hal/fdi/policy/10-linuxwacom.fdi:
The Smell of Molten Projects in the Morning 