Forum Replies Created
-
AuthorPosts
-
cmcgrath5035
ModeratorSo keep an eye on https://github.com/synthetos/TinyG/issues/268
I looked there before suggesting you post there, that is where real bugs get worked, this feels like one.
ModeratorWe learn something every day.
So now I (think I)know you are referring to
https://github.com/synthetos/TinyG/wiki/Gcode-Support#m115-get-firmware-version-and-capabilitiesHave you tried an M115 query from a simple command line console such as CoolTerm (por putty, etc)?
I don’t have a machine online at the moment, this might perhaps be just a bug.
First I have ever seen this question.Are use user “fxrb” ?
I see this here
https://github.com/synthetos/TinyG/issues/268-
This reply was modified 3 years ago by
cmcgrath5035. Reason: links not displaying
ModeratorIf you really want to dig in on this, study G2, the evolution of tinyG into ARM space and much more 3D printer centric. It also has a more robust build system should you want to experiment.
ModeratorSorry for delay, the system has stopped sending me messages.
I have not seen this specific question asked, but will guess that what you seek to do is not easily implemented.
Have you read any of the Wiki items, such as this one https://github.com/synthetos/TinyG/wiki/Jerk-Controlled-Motion-ExplainedI theory you might write something that broke up the G1 motion into tunable segments, but even that would likely not be effective since the Planner would concatenate the artificial segments and plann them all togeather anyway.
ModeratorI understand your challenge, see no easy solutions with Gcode. You could of course craft some custom code.
Over the years I have seen several posts related to “pick and place tinyG”.
Try a search on that topic, perhaps some of those forums have addressed your issues.
Should you choose the custom coding route, you maty also want to consider the G2 code platform, more hw performance and a more active development environment.ModeratorKeep an eye on things. I have no idea what sort of machine or jobs you are running. IF(still not conclusive) marginal drive into your SR4+ was the culprit, you are essentially running a digital system in a fuzzy space between full digital precision and analog. Minor power variations, room temperature, etc could effect operation and or accuracy. Use the least amount of microstepping in your system to get the precision you need. Microstepping is an inherently analog process, playing with phase relationships in the windings.
That said, good luck with your projects
ModeratorI think it is not a good assumption.
From looking at the schematic, that jumper only affects the Spindle out put levels.
The VDD to the core processor is 3.3v and the connections to the 8825 drivers are direct. You could probe the enable[bar] with a volt meter to verify.
Did you try power management always on to see if that improved the delay observed. Of course if enable is being delayed, it is possible the other signals will suffer similar distortion.The V9 was an early prototype development board, it did find it’s way into a few start up projects. Never fully documented.
ModeratortinyGV9 is 3.3v logic. Are you using level translators between V9 and the SR4+? if not, you might be seeing a slow turn on of the enable (bar) signal due to low current drive.
Choosing power management to always on will not be much different than power management= in-cycle, as long as you remember to turn off the motors when you machine is idle. If $pm=1 works better, , then level translators might be in your future
See https://github.com/synthetos/g2/wiki/G2core-on-DUE—External-InterfacesModeratorNo, I am not sure because I don’t have any specific information about the DM556 you purchased, I am using some reasonable assumptions about it, specifically that the pulse, dir and enable inputs are positive logic.
Do you have access to a cloud drive service, such as Gdrive or Onedrive or DropBox (or…)
This is a rather un-modern forum tool and does not have great support for attachments.
Best way to make a picture available is to copy it to the cloud drive, copy the url to your clipboard then paste that text URL into your forum postThat is how all the URLS I have provided you are inserted. I am assuming they are working for you, is that accurate?
ModeratorIf you want to dig even deeper, you can pull up this datasheet for the TI 8825 driver, the one that is on tinyG(four times).
ModeratorYou should read this link(from the yellow area at top of this thread), it may help you better understand how stepper motors work,
https://synthetos.com?post_type=topic&p=6214Also, Please start a new thread, this one is getting way too long and getting hard to navigate
ModeratorI am not sure how the controller works, if in fact it rests as a closed circuit and needs a signal to open the connection between the stepper coils to unlock it, this may very well be the problem. What do you think?
I am not 100% sure what you are asking here, but I can guarantee you the detailed answer is well beyond the scope of what we can do here. Keep in mind that most all logic leads and the actual connection to the stepper windings are pulses, not DC levels that you can read usefully with a voltmeter. Perhaps what follows will help.
The Term “enable – bar”, silkscreened on my tinyG as enable with a bar across the top, is standard speak in logic circuits that when I say “Enable is active”, the enable -bar lead will be a logic low, approx 0 to 0.1V.
That is the way tinyG firmware signals Enable is active or inactive. The enable lead is programmed to be ‘active-low’ because that is what the onboard 8825 stepper driver chips expect.Upon reset, tinyG will turn on the driver device for $mt seconds. During that interval, the step lead and dir lead will be off, and measure 0 volts.
When the stepper driver device sees enable on and pulse and dir off, the stepper device is signaled to hold position with pulsed voltage applied to all 4 winding leads at appropriate phases. After $mt seconds, the enable lead turns off, which is 3.3V.Go back and see if you observe that behavior, voltmeter measuring the enable-bar pin before and after you hit the reset button.
Power up tinyG, wait 5 seconds. now probe the enable bar pin, it should be high(3.3v). keep the prob on the enable bar pin and hit reset, you should
see the pin drop low for $mt seconds, then return high.
Wiring 3.3vdc to enable+ on the DM556 and the enable bar to enable- on the DM556 inverts the enable bar logic.All this assumes that the DM556 inputs are all positive logic. You need to get me the spec sheet URL. Just copy it from browser and paste it her(the URL, not a screenshot of the image.
ModeratorYou are correct, Pulse == Step
In some documentation, you will see it referred to as a step pulse.It sounds like a possible issue with the enable signal
On power up, the motor should be energized to hold current position for $MT seconds. In other words, Enable should be active for $mt seconds and then enter disable state.
Review your connection to the Enable leadsModeratorA1 and A2 are A+ and A-, but you may find direction gets reversed. There are no universal color coding or nomenclature standards
I copy a link and simply paste it
ModeratorThese are best guess, scraping info from the Amazon sell page.
If you have a link to a specific manual page, send itThis diagram is about as good as it gets
https://github.com/synthetos/TinyG/wiki/Connecting-TinyGWork one motor/driver at a time. start with Motor 1
Connect the stepper windings to A+ A-, B+ B-
Connect 24V power supply to +V and GND on the DM556Set SW1 -off, SW2 off SW3 on and SW4 on to select 3.2A drive current to stepper
You have $sa=1.8, so you you have 200 steps/rotation steppers.
You have $mi=8 (8 microsteps per step) so you want a setting of 1600 (8*200) Pulse/rev.
Set SW5 = off, SW6 off SW7 on SW8 onFrom J17, the logic pins for Motor 1
Connect Step to Pulse+ on the DM556
Connect Dir to DIR+ on the DM556
Connect Enable[bar] to ENA – on the DM556
Connect Step- and Dir- on the DM556 to tinyG Gnd (not DM556 GND)
Connect ENA+ on the DM556 to the 3.3V lead on J17See if you get motion on Motor 1
I can’t look over your shoulder, so if you don’t understand ask before powering up.
You will likely get motion as desired, but given the specs I suggest you follow up with the 3.3V to higher voltage logic translators. 3.3V drive will likely be marginal on the pulse, dir and enable inputs.
-
This reply was modified 3 years ago by
-
AuthorPosts
