I am trying to implement microstepping on a X-NUCLEO-IHM05A1, which i am using with an Arduino uno. I have followed the microstepping application note, and i obtained the right waveforms at l6208 references' input pins. Here you can see the waveforms obtained with my oscilloscope. Of couse the sinusoidal waveforms have been probed at the onboard low pass filter's output. 1 and 2 are respectively the waveforms for refA and refB, while 3 is the Clock signal fed to the shield.
At setup i have also implemented the initialization routine, which briefly is Reset, then apply 5V to both refs, than apply PWM with 0.7 DC on both refs.
At the end the stepper doesn't rotate in a single direction, but rather oscillates between two position with a swing of several steps, probably 5 or 6.
Do you have any clue or hint of what could cause this behaviour? I thought about the power supply, and the one i am using is a standard wall plug one with output 12V and 1.5A, which seems to work smoothly with another board based on L298 and same stepper motor, so i don't really think this is problem. But i have tried also with a bench PS unit and with higher voltage (say 20V and 4A) and the stepper could rotate but not steadily and very noisily. Thanks for the help.