cmcgrath5035

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  • August 30, 2017 at 9:06 am in reply to: Alternative to PWM spindle #10531
    cmcgrath5035
    Moderator

    I’m not offended at all. I’m quite new to tinyG (yes, tinyG, not G2) and perhaps I might be wrong but as far as I understand the project is opensource. Hence, it should be enough to de-solder the xmega and replace it with a new one (which I have in my drawers) and using AtmelStudio to flash the hex of the bootloader before download the latest firmware. Is it correct?

    You are Correct.
    The tooling and skills required for this is not typical for Forum users, including myself.

    Yes, the PWM worked a while without any connection on the terminal blocks. I’m pretty sure I accidentally connected the wrong wire (it was too early in the morning, gh…). The spindle pin works fine but I don’t understand your question: it’s on a different port (PA5). It would be more useful to know if other pins of PORTD still work, wouldn’t it? Anyway, they seem to work…

    That question had two motivations. 1, determine if you knew how to turn PWM on and off. Obviously, you do. 2, Get a rough feel for how much damage to the I/O structure on the XMEGA had been done. I fully agree that determining functionality on Port D would be a good thing before proceeding. As well as looking at chip physical layout to see what else might be in the vicinity of the Port D5 output structure.
    Here is a good reference if you don’t already have it

    Is the Coolant I/O pin functional? If so, and not used by your application, recompiling with the PWM connected to the Coolant external port might be your quickest try.

    Very few Forum users are equipped to handle the gory details of recompile tinyG, folks off on that tangent do tend to head directly to the Issues interface for advice.
    It is not a question of off-topic, more that you might attract input from other tinyG users working at the recompile level over at Issues, as well as the developers.

    If your Coolant lead is still functional, give it a go.

    Good Luck !

    • This reply was modified 7 years, 2 months ago by cmcgrath5035.
    August 30, 2017 at 7:05 am in reply to: Alternative to PWM spindle #10528
    cmcgrath5035
    Moderator

    Anyone who says “I would be able to replace the MCU and flash the bootloader” immediately gets a bit of questioning respect, please don’t be offended:

    We are talking tinyG, not G2core(DUE), correct?

    Interface did work for you with the settings you attach?
    They look OK, but I have never seen anyone set speed hi to 1000 RPM.

    I am not a developer, but have seen reference to PWM2 on G2Core.
    Looking in tinyG/pwm.c, I do see reference to PWM2, but in an ifdef __ARM block, which is DUE code (common code base), I believe.

    Assuming an ‘electrical event’ damaged the I/0 port pin hardware, are you thinking using a different output port on the XMEGA?
    Which one?
    I am not sure there are any unused Ports.
    Schematics here

    What you ask about here is really beyond the normal scope of this Forum.
    I’d suggest you post a question at

    Add info related to my questions above.
    The Issues area is much closer to the developers.

    It might be useful info to report if the Spindle PIN (simple on/off control) still operates properly

    Good Luck with your fix

    • This reply was modified 7 years, 2 months ago by cmcgrath5035.
    August 26, 2017 at 12:56 pm in reply to: how to move # steps not to position… #10523
    cmcgrath5035
    Moderator

    Nope, not SPI, native USB as you are doing.

    I am not familiar with Windows device management enough to know how to lock a particular ftdi device to a COMx port. I am rather sure it can be done.

    Unless I underestimate the scope of your final project, I bet you could operate your universe on a <10watt RasPi3.

    August 26, 2017 at 9:06 am in reply to: how to move # steps not to position… #10519
    cmcgrath5035
    Moderator

    Cool! You are on your way.

    Tweaking $afr might work OK, but may only be effective (accurate) for one f-value, e.g. f400. Rerunning “g1 f200 x2 y2 z2 a2” would not be similarly equalized by the $afr value

    This wiki might help

    Fast forwarding to a future phase where you need to simultaneously drive 6 tinyGs to provide 22 stepper drivers:
    tinyG uses an FTDI USB to serial device as the front end interface to the host computer. While it is possible to bypass USB and hard wire a serial interface, finding control computer with 6 serial ports might be a challenge.
    Each ftdi device has a unique device ID.
    In Linux land, it it possible to force a particular ftdi ID to mount as a specific /dev/ttyUSBx device using UDEV rules.
    That way you would have a reproducible interface to your universe upon reboot. That would probably make programming and debugging a bit easier.
    I’ll assume this is similarly possible for Windows and macOS, but no experience.

    • This reply was modified 7 years, 2 months ago by cmcgrath5035.
    August 24, 2017 at 12:31 pm in reply to: how to move # steps not to position… #10515
    cmcgrath5035
    Moderator

    From this

    I believe the answer is no, not for what you need anyway.
    What you meant to ask, I believe, is can 4 unique rotational axes be defined and decoded simultaneously, for which the answer is no.
    It is possible to attach 2 motors to one axis(.g. A axis), such that the two motors follow the G0 Axy command, but that is not much help for you.
    X,Y and Z are linear axes, A,B and C are rotational by definition; modifying firmware to change that might be difficult.

    Also review this

    I think this strategy might work for you:
    + Plan to generate your control program in units = degrees of rotation
    + set $xtr=360 $_tr is travel per rotation,
    + set $aam=$bam=$cam=1, standard rotational, move in degrees
    + set $xvm,$avm, $bvm and $cvm appropriately for how fast you want moves made.

    This generates an interesting question, for which I don’t have a definitive answer.
    Assume you are in G90, absolute mode.
    With the above proposed setting, G0 X270 will move 3/4 rotation. Then sending G0 X0 will reverse direction back to 0.
    I can only assume that G0 A270, followed by G0 A0 will behave similarly, although continuing forward 90 steps would get there faster.
    In G91, relative mode, G0 X270 followed by G0 X90 and G0 A270 followed by G0 A90 will behave the same a yield one full rotation, I expect.
    But after those commands, Xpos will be 360, where as I believe Apos will be 0.
    Experiment with your A axis, I don’t have a machine handy at the moment.

    Hint – make a flag on the shaft of your stepper with masking tape, keep $avm slow so you can watch what is happening.

    • This reply was modified 7 years, 2 months ago by cmcgrath5035.
    • This reply was modified 7 years, 2 months ago by cmcgrath5035.
    August 21, 2017 at 8:22 pm in reply to: Where is my order ? #10513
    cmcgrath5035
    Moderator
    August 21, 2017 at 8:19 pm in reply to: how to move # steps not to position… #10512
    cmcgrath5035
    Moderator

    (I hear Murphy sneaking up behind me).
    Here are a few random thoughts/questions that have come to mind after understanding what you need to do.
    + Are you expecting that NEMA 17 (or smaller) motors will be adequate for each of your 22 rotators?
    ++ tinyG, with 4 on-board drivers, is about as dense as you can get.
    ++ if you think you will need NEMA23s, you had better come up with a good thermal management plan.
    +Am I correct in assuming that this display will operate in somewhat real time, e.g. the earth will rotate around the sun once a year, moon around the earth once a month. Or do you have a ‘millennium evening’ event planned, 100 years between 8 and midnight?
    ++ question is really how fast the Gcode will need to be delivered to the units.
    +what is your current thinking – 6 tinyG’s providing drive for 6×4 = 22 motors?
    ++ I would be cautious assuming two tinyG’s linked together is a safe plan. The electrical interfaces might be there, I have never seen anyone try it
    ++At best 2 tinyG’s in series would drive 6 motors, waste 2 drivers. tinyG logically only decodes motion for 6 axes – x,y,z,a,b,c.
    ++ Hobbyist CNC has moved on since a possible series connection of tinyGs was enabled in the hardware. Most current effort is aimed at 3D printing applications. Newer hardware platforms have been in the works for a while, will appear soon. They will be G2core based.
    + How do you plan to initiate your machine’s motion? In CNC space, some users install homing switches, run homing cycles and set a predetermined starting point for movement. Others just grap hold of the gantry and drag it to a ‘starting point’ then reset tinyG. When tinyG resets, all 6 axes are set to 0 at whatever position they are at. Manually zeroing 22 separate rotators might not be practical.
    ++ Something is going to fail or glitch. Only you will know if everything is in the ‘correct position’, but why do this if it isn’t correct?

    All for now – you have a very interesting project going.

    August 21, 2017 at 7:53 am in reply to: how to move # steps not to position… #10508
    cmcgrath5035
    Moderator

    I am guessing you are the developer of the solar system project.

    You are correct, a G0 X100 Gcode command will move the X axis either 100 mm or 100 inches, depending on your units setting. It will make the move of 100 units either to an absolute position (x=100mm) or move 100 mm in the positive direction, depending on the movement mode (absolute, relative).

    A good reference point to start at might be here

    Basically, you need to tell tinyGV8 about stepper driver parameters and motion conversion (e.g. gearbox) parameters so that it can calculate the number of step pulses to send to the stepper to achieve the move.

    Can we assume you will be hand coding the Gcode for this project? I am not aware of any Gcode generator that would do it for you.
    My initial guess might be you would want to use rotational axis commands for your task. For example, G0 A180 would move a stepper, properly configured, one half rotation (180 degrees).

    As you read thru and contemplate your coding strategy, keep in mind that that tinyG uses all these parameters to translate a command into an action which sends a number of step pulses to the stepper driver. So the ‘precision’ of an axis is the distance moved with one step pulse.

    Be aware that “My final gear will move 1 degree for 100 motor steps.” leaves out some possibly important information about how to set parameters.
    For example, a typical stepper has a 200 steps per rotation spec, a step angle of 360/200 = 1.8 degrees per step. That is a physical parameter of the motor. Most stepper driver devices(the electronics) have microstepping capabilities, which use phase offsets between the windings to ‘synthesize’ partial motion, So if microstepping = 2, the driver device will make the stepper appear to need 400 step input pulses for a complete rotation. You might want to read thru a driver device spec sheet to see how this is done.
    From you “My final gear will move 1 degree for 100 motor steps.” comment, I would conclude that the stepper drives a gearbox with a 180:1 gear ratio, is that correct?

    July 29, 2017 at 10:29 am in reply to: g2core line mode / protocol question #10496
    cmcgrath5035
    Moderator

    I just added some comments to your Issue 1 at node-g2core-api.

    Seems node8.js is needed.

    I did not try to send a gcode file

    • This reply was modified 7 years, 3 months ago by cmcgrath5035.
    • This reply was modified 7 years, 3 months ago by cmcgrath5035.
    July 26, 2017 at 3:16 pm in reply to: TinyG and a lathe? #10492
    cmcgrath5035
    Moderator

    I and J are arc codes coordinates.
    I believe you can tell the post processor to generate only linear (G1) commands

    July 26, 2017 at 3:13 pm in reply to: Flashing SPINDIR – POWER LED #10491
    cmcgrath5035
    Moderator

    If you can’t update via the cli method with avrdude,

    then there is a good chance your bootloader is missing, overwritten by something. The most common cause is dragging a binary file onto the CP gcode widget in error.

    Anyway, to recover you need a programmer or contact the Synthetos folks at

    and send it to them for reflashing

    July 26, 2017 at 3:05 pm in reply to: Cannot upgrade to Firmware Build 100.26 #10490
    cmcgrath5035
    Moderator

    As you have likely found, 100.26 sets $ej=1, json mode sticky, by default.
    Chilipeppr does not care, but it makes CLI interfacing difficult unless you like reading json responses.
    Setting $ej=2 will switch back to auto mode.

    July 26, 2017 at 11:06 am in reply to: Cannot upgrade to Firmware Build 100.26 #10487
    cmcgrath5035
    Moderator

    The v9K pinout is different from due, I suspect that 100.26 was running but you could not see the heartbeat.

    You will have to build a gShield version, there is no prebuilt.
    I built on Linux a couple days ago.
    After cloning the source from git, see Issue 272

    run the git revert to add back the gshield-pinout.h file make should build you a bin that loads and heartbeats

    July 25, 2017 at 8:52 am in reply to: g2core line mode / protocol question #10484
    cmcgrath5035
    Moderator

    Interesting, good find. I’ll keep an eye on Issue 287

    July 25, 2017 at 8:49 am in reply to: TinyG and a lathe? #10483
    cmcgrath5035
    Moderator

    I figured it might be you.
    I have not seen much about the CAD/CAM front end for lathe operation, or how the required motion might be mapped to X-Y-Z-A.

    There is also a mindset issue here – when one says lathe, I think of parts that are cut from a continuously rotating piece of stock, symmetrical about the spinning axis.
    Or is your goal to make the lathe axis the A axis and to create objects that are asymmetrical about the rotational axis.

    I don’t see why tinyG could not move the motors, assuming that the Gcode made sense.

    Let us know what you find

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