potentiometer as rotary encoder.

I am going to control some vernetian blinds with an arduino. Ive managed to mount a small geared motor inside already, but i need to know the limits of the blind is. I was thinking of using a potentiometer so i can also see the position by the feedback of the voltage. I can mount this in the blind quiet easily too.

Now i am worried about over time the potentiometer will wear and spike, so i am just wondering if there is a better way?

The blind has a 4mm D shaped shaft all the way threw it, and the potentiometer also provides a solid limit too.

thanks

What kind of pot do You use?
Search for a durable version.

you think if i get a good one itll be fine? what would you go for ? Like a 10k one?

Ive spotted they do them with 6mm shafts which is really good for this project.

A good quality pot used within its specifications should last a long time. The data sheet should list a MTBF or expected life time. This data sheet lists life as: Rotational Life: 2000K cycles.

thankyou that is more that good enough for my blinds. ill get some ordered and go for it!

avtovaz:
thankyou that is more that good enough for my blinds. ill get some ordered and go for it!

Are we discussing rotary potentiometers or slider type potentiometers?
Paul

rotory

A normal rotary potentiometer has a sweep of about 270 degrees. That is, you cannot continuously rotate it unlike, say, a rotary encoder. Is that enough for your application?

Hi,
Welcome to the forum.

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How many turns does the blind shaft you want to connect the pot/encoder to rotate, when you operate the blind from max to min height?

Tom.... :slight_smile:

If all you really need to know is whether the blinds are fully up or fully down a set of limit switches is usually the way to go. If you want a stop halfway you may add another switch to detect that point.

Normal pots indeed go only about 3/4 turn so probably not enough for your blinds. There are multiturn pots but I only know those as trim pots and they won't be too happy being moved hundreds let alone thousands of times.

oh thanks for the replies, its not the up and down of the blind, its the tilt of the blades, so not a full rotation is fine, and also will act as a limit to how far they can tilt. Will post some pics up maybe later!

Maybe a bit late... but replace the DC motor with a servo and you're all set.

wvmarle:
Maybe a bit late... but replace the DC motor with a servo and you're all set.

Check the need of torque first. Some blinds needs torque. They are not always running easily.

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