Merci pour ton intérêt JF,
Les broches de configuration des microsteps des drivers (easydriver ) ne sont pas connectées; de mémoire =full step.
ce qui me frappe c'est qu'en envoyant:
G91G1X-50.0F500
G91G1X-50.0F50
G91G1X-50.0F5
le déplacement se fait toujours à la même vitesse
je joins au message le config.h de Grbl
les réglages Grbl sont les suivants:
voici
$I
[0.9j.20160726:]
$#
[G54:-209.174,-215.859,-9.600]
[G55:0.000,0.000,0.000]
[G56:0.000,0.000,0.000]
[G57:0.000,0.000,0.000]
[G58:0.000,0.000,0.000]
[G59:0.000,0.000,0.000]
[G28:0.000,0.000,0.000]
[G30:0.000,0.000,0.000]
[G92:0.000,0.000,0.000]
[TLO:0.000]
[PRB:0.000,0.000,0.000:0]
$G
[G1 G54 G17 G21 G91 G94 M0 M5 M9 T0 F10000. S0.]
$$
$0=10 (step pulse, usec)
$1=25 (step idle delay, msec)
$2=0 (step port invert mask:00000000)
$3=4 (dir port invert mask:00000100)
$4=0 (step enable invert, bool)
$5=0 (limit pins invert, bool)
$6=0 (probe pin invert, bool)
$10=3 (status report mask:00000011)
$11=0.010 (junction deviation, mm)
$12=0.002 (arc tolerance, mm)
$13=0 (report inches, bool)
$20=0 (soft limits, bool)
$21=0 (hard limits, bool)
$22=1 (homing cycle, bool)
$23=3 (homing dir invert mask:00000011)
$24=25.000 (homing feed, mm/min)
$25=500.000 (homing seek, mm/min)
$26=250 (homing debounce, msec)
$27=3.000 (homing pull-off, mm)
$100=3.000 (x, step/mm)
$101=4.000 (y, step/mm)
$102=25.000 (z, step/mm)
$110=900.000 (x max rate, mm/min)
$111=900.000 (y max rate, mm/min)
$112=50.000 (z max rate, mm/min)
$120=10.000 (x accel, mm/sec^2)
$121=10.000 (y accel, mm/sec^2)
$122=10.000 (z accel, mm/sec^2)
$130=290.000 (x max travel, mm)
$131=180.000 (y max travel, mm)
$132=47.000 (z max travel, mm)