[51] Idea needed for stepper motor control

[a4speaker]

For my project, stepper motor will be used to rotate thermostat knob.
My problem is i want stepper motor to rotate to the shut off position of knob. When the knob is not moving(obviously it has some shutdown point), stepper motor should stop rotating.
Is there any mechanism for microcontroller to know that stepper motor is not moving anymore and shut it down?
Any ideas how can i do this?

 

[embpic]

yes you can use limit switch or other sensor to sense the limit.

 

[graphene]

you can also implement this if u r using mocrocontroller by defining the steps or angle... this is infact a simple process...

 

[embpic]

yes if you know the steps required to reach the end then it will easy rather than using any extra components

 

[a4speaker]

actually i dont know the number of steps. my project requires that motor will shutdown thermostat and will resume it to same position after some time.

 

[graphene]

i have not mentioned or defined the number of steps... it is upto you to define and and use it.. or in terms of angles/degrees....
.
example: 180degrees to 90 degrees, left to right for a complete ON status or so.... it is a not a definition but a suggestion..

 

[gehan_s]

If you are not comfortable with the "step" method then you can always make a circuit open or close when the knob has reached a certain point like in the picture. But the previous idea is better and if you are presenting this to someone you can avoid awkward moments where people ask why you didn't use the step approach.

Regards

 

[nick703]

For my project, stepper motor will be used to rotate thermostat knob.
My problem is i want stepper motor to rotate to the shut off position of knob. When the knob is not moving(obviously it has some shutdown point), stepper motor should stop rotating.
Is there any mechanism for microcontroller to know that stepper motor is not moving anymore and shut it down?
Any ideas how can i do this?

Obviously in running stepper motor and also know about step then u will use opto sensor like below image
https://www.google.co.in/search?q=opto+-sensor&source=lnms&tbm=isch&sa=X&ei=bwoGU47fFMOrrgf-34CgAw&ved=0CAgQ_AUoAg&biw=1024&bih=629#facrc=_&imgdii=_&imgrc=TsM4fOTLR9XUoM%253A%3Bi-uDbbd8pwMZ-M%3Bhttp%253A%252F%252Fwww.ticketflex.com%252FVideo%252520Tips%252FOpto_interruptor.gif%3Bhttp%253A%252F%252Fwww.ticketflex.com%252FVideo%252520Tips%252FOpto%252520Interrupter.htm%3B640%3B480
and u will stop the stepper motor .


another question is simple to about stepper motor rotate at 1.8 degree or 0.9 degree then one complete revolution required step is 200 or 400 . in your case what is your stepper motor step angle?

once u know the complete step required to reach destination motor will automatically stop . and also put some more detail bro!!!!

 

[embpic]

First you have to check how much pulses you are giving to stepper motor how to reach there after that give that much number of pulses.