I'm using the 28BYJ-48 stepper to drive a mini CNC machine, I use the arduino nano shield v4 and 3 a4988 and wiring 28BYJ-48 as a uni-polar.
I noticed that using the grblmain library making the motor to work improperly and skip steps.
I tries changing the pulse width to 20u but I'm not sure if its enough and what is the minimal pulse width and delay between steps. I couldn't even find the data in any datasheet.
so... can anyone tell what is the minimum delay between steps and minimum step width for the 28BYJ-48?
this is the current grblmain configuration
$0=64.000 (x, step/mm)
$1=64.000 (y, step/mm)
$2=1024.000 (z, step/mm)
$3=20 (step pulse, usec)
$4=250.000 (default feed, mm/min)
$5=250.000 (default seek, mm/min)
$6=24 (step port invert mask, int:00011000)
$7=25 (step idle delay, msec)
$8=10.000 (acceleration, mm/sec^2)
$9=0.050 (junction deviation, mm)
$10=0.100 (arc, mm/segment)
$11=25 (n-arc correction, int)
$12=3 (n-decimals, int)
$13=0 (report inches, bool)
$14=1 (auto start, bool)
$15=0 (invert step enable, bool)
$16=0 (hard limits, bool)
$17=0 (homing cycle, bool)
$18=0 (homing dir invert mask, int:00000000)
$19=25.000 (homing feed, mm/min)
$20=250.000 (homing seek, mm/min)
$21=100 (homing debounce, msec)
$22=1.000 (homing pull-off, mm)