Yes I still had my stepper wiring mixed up.
Yes I have bricked two A4988 boards (d'oh, it's ok they died for science, a moment's silence is in order ... thank you, more coming in the post tomorrow)
As for my home-brew board, good and bad. The Z axis seems dead but the X and Y axis live although there seems to be excessive heat on the chips. A short somewhere? I think maybe something's wrong with the enable pin, R10K, VDD wiring also.
Anyway, I did build a single axis controller on a breadboard and that's what I've been testing with and hey presto X50 sends the motor spinning CW and X0 sends it back again CCW from whence it came.
Previously they wouldn't turn, they'd just jog and never finish a command. Also now I can't turn them with my fingers when they're powered up, before I could.
But I'm not happy yet as ... with the belt on nothing moves
. It just whines. Is this what is known as stalling?I need to see a gantry moving before I can sleep!
So I guess you need to know my setup ...
Turns out I wasn't using the revision 3 schematic for my home-brew of the Buildlog.net stepper shield I was using revision 2 so I had to modify and recompile GRBL to account for the different pin config. I've followed the same pin config for my breadboard circuit so I can leave GRBL alone for now. As I can get a stepper to stop/start, go CW and CCW I figure my compiled version of GRBL is Ok. I used the mods to Config.h and Stepper.c detailed in the WiKi somewhere - edited in Xcode and compiled using avr-gcc. Anyway ...
GRBL 0.7d with pin config modified to match earlier versions of Buildlog.net shield. Set as follows ... (again they're got from the Wiki somewhere!
You know how easy it is to lose track of the decisions you make/info you use when tinkering!)
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I tried all permutations of the micro-stepping jumpers. Some were Ok, some killed it, some caused juddering. I'm not sure on the right setting here. Here are my stepper motors http://www.technobotsonline.com/stepper ... s-rev.html
. My drivers are the Pololu A4988 breakout boards. My belts on the mechanicals have plenty of play and the gantry moves freely and smoothly.
Things I will do next or haven't done yet
Set current limit on A4988 boards (looks fiddly!)
Used a GRBL calculator for my setup to get GRBL settings
Shelve my home-brew board for now and extend breadboard controller to other 2 axis
As I'm shelving home-brew shield I could update pin config to standard GRBL and use latest build too which IIRC is 0.8?
Where should I go first? Running out of allotted time for this this week, would love to see a gantry move before I must put things away for a few days!