Setting Motor Currents- M906

sinned6915

I am tying to learn about setting motor currents, M906. Not sure if this post goes here in FW Installation or Tweaking forum.

If you are using stepstick / stepper drivers with digipots to set Vref, would you use M906 at all ? I used the online configurator and didnt think about it, the M906 is in my config.sys file even though I am using DVR8825's all around, because I choose the wrong board to config with.
If you have a mixed system with digipot boards and a stepper driver boards that are capable to have the current set by firmware, do the values in M906 for digipot drivers matter? Using 0's here does not feel comfortable.

Example- X & Y have SD6128s, Current Limit is VREF*2, Motors are 2A, current would be 1.0a or 1000ma.

Z, E0 and E1 are DRV8825's, all at Current Limit is VREF*2, Motors are 1.5A.

M906 X1000 Y1000 Z0 E0:0 I0

Thanks in advance

Dennis

Stephen6309

@sinned6915 M906 controls the stepper current on the drivers on the Duet and the DueX boards. For the 8825s, it won't set the current.

sinned6915

Stephen-

I am trying to determine if I can MIX digipot drivers and FW current set drivers on the same system. I am working towards 3 independent Z leveling screws.

Can you have mixed stepper drivers in the system?

On my stepstick breakout board I will have all DRV8825's for the three Z motors.

The X, Y, E0 & E1 will be the current setting kind.

M569 P0 S1 ; Drive 0 goes forwards X
M569 P1 S1 ; Drive 1 goes forwards Y
M569 P2 S1 T1.9:1.0:0.65:0.65 ; Drive 2 goes forwards Z1
M569 P3 S1 ; Drive 3 goes forwards E0
M569 P4 S1 ; Drive 4 goes forwards E1
M569 P5 S1 T1.9:1.0:0.65:0.65 ; Drive 5 goes forwards Z2
M569 P6 S1 T1.9:1.0:0.65:0.65 ; Drive 6 goes forwards Z3

M584 X0 Y1 Z2:5:6 ; three Z motors connected to driver outputs 2, 5 and 6
M671 X-15: 100:215 Y190:-10:190 S0.5 ; leadscrews at rear left, front middle and rear right ; There is and extra space in there on purpose at X-15 b/c unicode chars displaying
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M906 X1000 Y1000 Z0:0:0 E800:800

Veti

are you using the LPC port? if so the LPC port does not support the M906 command at all.

dc42

@sinned6915 said in Setting Motor Currents- M906:

I am trying to determine if I can MIX digipot drivers and FW current set drivers on the same system. I am working towards 3 independent Z leveling screws.

Yes you can. The M906 and M350 settings for the external drivers will be ignored.

sinned6915

Thank you gents