Back EMF counting on new Pololu AMIS-30543 driver?

Hi, the new Pololu AMIS-30543 driver provides a SLA (Speed and load angle) - Pin for measuring back EMF voltage of the stepper motor.
There also exists a library with examples, but unfortunately it doesn't include a sample for this feature.

i tried to read the values of the SLA pin on an analog pin of my arduino Mega2560, but the values are not very significant. on lower speeds the input voltage is very low, at higher speeds i get better results, but everything is rather unstable to be used as a basis for correct step measuring.

so far the most significant output with the highest amplitude could be reached with the following settings:

driver set to transparency-mode ON (having the full range of voltage change, not only at the zero-crossings)
driver output current set to 400mA
microstepping mode: 128
step frequency: 50KHz

if i measure on my analog input pin, without any delay in my sketch, and send this to the serial output (also without any delays, set to the highest baud rate of 250000), i get the following values in my serial monitor:

320
322
323
322
320
1011
1013
1012
1013
1012
1012
1012
1013
1011
1013
1016
1012
1012
1012
1013
1012
322
324
324
323
322
323
324
326
322
324
324
325
324
323
323
323
323
322
323
322
324
322
322
322
324
1011
1012
1012
1012
1012
841
841
1012
1011
1014
1013
1012
1012
1013
759
757
760
1012
1014
1012
1013
1012
1012
1014
1013
1011
1014
1013
1012
1012
1012
1013
1012
1012
1012
1011
1012
1012
1012
1012
1013
1011
1012
841
843
1012
1011
1013
1013
1013
1012
1013
748
746
749
1012
1012
1012
1013
1012
299
303
302
301
302
302
303
300
301
300
301
299
300
300
296
297
299
301
301
300
301
300
301
298
756
761
761
1012
1012
1012
1013
1012
1012
1014
731
730
732
1013
1013
1012
1012
1012
1012
1012
1012
1012
1012
1012
1012
1012
1016
1013
1011
1014
1013
1012
1012
1013
1013
1012
1012
1013
1012
1012
1014
1013
1012
1012
1012
1012
1012
1012
785
785
1012
1012
1014
1013
1011
1012
1012
1012
1012
1012
322

so, as you can see, there is a kind of continuity, but its hard for me to take it as a basis for further enhancements. what dou you think, is it possible, that this values show the real EMF values? somehow i have the impression, that it is more a kind of interference-wave...

unfortunately i have no oszilloscope, so i cannot measure the behavior of the SLA-pin more accurate.

has anybody tried this new driver-feature already? any suggestions?

Hi may be these values were for the transient period of the motor coz some of them are fluctuated , have you tried an simulting software instead of the oseliscope?...let us know you wonderful results....soon..