Stepper motor stops when ABS_POS register overflows.

[val_ltd]

Posted on January 27, 2013 at 23:05

Hello, I am trying to rotate my stepper motor 5000000 micro-steps (in 128 micro-steps mode) and its size is bigger than ABS_POS register size (it only has 22 bits in two's complement format).

When the register overflows, the motor stops, instead restart the register. What is the way to rotate more micro-steps than the register size, without stopping the motor? On the other hand,  Run(DIR, SPD) command only accepts data of 20 bits size ... Thanks, #abs_pos-register

[Enrico Poli]

Posted on February 04, 2013 at 15:43

Hello, the device is not able to manage a motion longer than the ABS_POS register size. If you send a Move or a GoTo command with an higher value the most significant bits will be truncated (e.g. a 5,000,000 motion is interpreted as a 805,696).

If you need to manage longer motion you have to do it through your microcontroller.Run command argument is the target speed value, there is no relation with the motor position.RegardsEnrico

[val_ltd]

Posted on April 13, 2013 at 10:50

Thanks, At the end, I did it as you told me.

[val_ltd]

Posted on April 13, 2013 at 11:10

I have moved my last questions to:

my.st.com/public/STe2ecommunities/motordriver_ics/Lists/Motor Driver ICs and Boards

[val_ltd]

Posted on April 13, 2013 at 18:11

I have moved my last questions to:

my.st.com/public/STe2ecommunities/motordriver_ics/Lists/Motor Driver ICs and Boards.