L6470 MIN_SPEED register

ivlasic · ‎2014-03-05

Posted on March 05, 2014 at 11:21

Hi,

Description of this Register is confusing me all the way.

It is written:

''

When the LSPD_OPT bit is set high, the low speed optimization feature is enabled and the

MIN_SPEED value indicates the speed threshold below which the compensation works. In

this case the minimum speed of the speed profile is set to zero.''

So, what i did is set the

MIN_SPEED

at zerro and set the

LSPD_OPT

high.

But somehow i dont see any difference.

I am running at low Speed and low voltage.

The Speed where i want that compesation will be active is 2,228 steps/sec

On one Hand it is written that min_speed is a treshold below which the compesation works and at the other Hand ist written that Setting

LSPD_OPT

hight will set this value to zerro.

So which Value schould I set at

MIN_SPEED

so that my stepper can run at 2,228 steps/sec and have the compensation working?

Regards

Igor

Enrico Poli · ‎2014-03-13

Posted on March 13, 2014 at 14:38

Hi Igor,

When you enable the low speed optimization you should set the MIN_SPEED value at few tens of step/s. This because the parameter change its function: it is no longer the minimum speed of the motion profile of the motor (i.e. the starting speed), but the threshold below which the low speed compensation is introduced.

The low speed compensation is a pre-distortion of the voltage sinewave, so it must be performed only when needed (at low speed).

Best Regards

Enrico