Hello Maker Forum,
Being new to my V1.1 Smoothieboard, …
It delivers (as quite usual !) “enable”/”dir”/”step” outputs before the drivers.
The drivecards I found in the ancient robot seem to have one input for “step forward” and one input for “step backward” instead. Unfortunately I dont even know how this concept is exactly called …
Shall I go for a small hardware/logic adapter or are there already better ideas/concepts/settings … around ?
Thank you very much !
Till.
Some pictures might help us all understand what you’re talking about here.
I’ve seen drivers with Step+/Step-, Dir+/Dir- and Enable+/Enable- is that what you have or does it really have only one connection for Dir and Enable and a +/- for Step?
Thank you very much for the fast replies, really happy to find a live project and a responsive Forum !!
The signal levels look much like common 5V, going to optocouplers, - no differential lines or so.
Enable signal is quite normal as well.
It´s just a different logic for the steps:
Small pulses (about 800ns each ) on one input to move forward, and the same pulses on the other input to move backwards. (( … dont know what would happen if I put pulses on both inputs simultanously … ))))
I should be able to get this pattern from your classic step / dir signals by adding some “glue-”logic TTL or CMOS gates, …: Generating one pulse per rising edge of your Step signal, and switching it with your direction signal to either of the two inputs. ((*_*))
Just wanted to know if threre exists already a jumper or config solution out there in the SmoothieWorld, before starting to built such a PCB or solder some breadboard …
Thank you again !!
Till
Smoothieboard and most all of the other commodity GCode boards were designed for common drivers which use the DIR pin to control motor direction so it sounds like you’ll either be tweaking the source code of one of the buffered firmwares or as you mentioned, building a logic intereface to sense the DIR+ and DIR- pulsing and either steer it to Step and manipulate DIR accordingly or replicate it at Step.
I’m curious what kind of robot it is, you’re not posting to CNC, Laser, nor 3DP sub-groups so not a typical use-case for a GCode controlled robot.
Hello dougl,
Thank you very much, !!
You are right, Firmware modification could be an option, if I should fail with my hardware adaptation.
The robot is some old version of https://d-t.com.tw/en/product-1/robots/dt-fn-series/
These are usually programmed with a Teach pendant which offers jogging, programming and geometric features. (( I did hate these pendants, beeping on every keypress and being quite anti-ergonomic … not so much of a pitty that I got the robot without !!! ))))))
I believe these gantry robots have their roots in the textile/sewing industry before evolving to dispensing, and have so, -on a maker scale-, an impressively heavy and stiff mechanic, the base table is thickly ribbed cast Aluminum …,
I could not find anything, not even a matching picture of the drivecards, maybe d-t could have built them their own, but I would really like to keep them, as they nicely drive the 3-wired (hybrid??) Stepper-Motors …
So it just cries for a new, G-code accepting, smoothie control … !!!
I do not kow yet where this project will finally land, perhaps I try the 3D printer direction first, but could get a light CNC mill for wood later on, thus I could not decide to a specific forum …
Thank you again , I will post if I have a working solution,
Till.
Sounds like a fun project. I would first try moving without any attention to which direction the motors turn and see what you’ll need to do to get the pulse rates correct for smooth motion. Once you get the Smoothie configuration.txt file setup for one axis direction then you’ll know you’re 90% there.
Next step would be a way to switch the STEP signal between Step+ and Step-which could just be a logic gates or something similar with the Smoothie Dir signal handling enable and not-enable.
Post a link to your video when you get things moving.