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Topic: Slider (Read 866 times) previous topic - next topic

TillMarkowitz

Need someone to write me a code for a camera slider, specs are as follows,
ULN2003 Driver
28BYJ-48 Stepper
Arduino Uno
Potentiometer to set travel speed over the 60cm slider
Switch to start/stop
LCD

Just needs to shows the time for it to move down the whole slider (minutes,hours) and for the potentiometer to change it.

Pulley Circumference will be 15.7 cm

PaulS

Quote
Pulley Circumference will be 15.7 cm
But what color is it?
'
Read your post. Can you figure what the heck the pulley has to do with anything?
The art of getting good answers lies in asking good questions.

ChrisTenone

But what color is it?
...
I say that all the time at work, etc., and nobody gets it. I wondered if anyone else had read that far!
I'm not disparaging the differently abled. It's just that thirty years of community college has literally made me mentally retarded.

PaulMurrayCbr

Ok, so if the pulley circumference is 15.7, and the slider is 60cm, and the stepper is a 48-pole stepper, then that comes to about 183 steps.

Oh, and this is quite slow - a time-lapse situation. So you'll set the thing up initially by hand, dial in the time, and then hit the button. No need for a UI to move the stepper back and forth, to reset its position.

And you want to use a potentiomter? A potentiometer on an analog port has a resolution of 1/1024. If the upper bound for your timing is hours, then one "tick" of the pot will be three seconds … and even that's not realistic to expect because we are talking very fine adjustment.

Another wrinkle is that the clock on an arduino UNO is not terribly accurate - it can be off by as much as 10%.

But … if it doesn't really need to be as accurate as all that, if ballpark is acceptable, then this is do-able. Set time with pot, display on LCD, then when the button is hit begin stepping and display amount remaining. Power cycle the whole dooverlackie to reset.

The main difficulty with programming this is setting up all the hardware. I have all the bits you are using, but it's all in boxes. The other difficulty will be getting all the pins and whatnot on my setup to match your setup.

Then again … I've been looking for an LCD project, just to get my feet wet.

Look - it's laundry day, and my 3d-printer has been disappointing me for days. I'llput it away and have a bash at this, but I will have to ask for more than my usual fifty buck minimum for an easy project because of all the hardware setup. I'll say $100 AUD, and that's for the very basic thing I have outlined here. Payment on delivery, because there's never a guarantee that the project won't blow out.
http://paulmurraycbr.github.io/ArduinoTheOOWay.html

PaulMurrayCbr

#4
Mar 26, 2017, 07:30 am Last Edit: Mar 26, 2017, 07:33 am by PaulMurrayCbr
update - I have the sketch written. I belive that one of the coils in my stepper is fried, however the LEDs on the pins in front of the ULN2003 are all lighting up in the correct sequence.



The display is very basic - you set a time in minutes, then as  the stepper moves the display shows time remaining and percent complete. There's no pause or reset or anything like that - once you press the button the thing just goes.

Pinout for the display is for a duinotech 16*2. The relevant part of the code, which you may need to modify, is:

Code: [Select]

const byte buttonPin = 2;
const byte potPin = A0;

LiquidCrystal lcd( 8, 9, 4, 5, 6, 7 );
Stepper stepper(48, 10, 11, 12, 13);

const int MAX_MIN = 60 * 3; // three hours
const int MIN_MIN = 5; // five minutes
const int TARGET_STEPS = 183;


This lets you set a time from five minutes to three hours in one minute increments with the pot.

I'll tell you what, this wasn't all that much of a hassle. If you are happy to take the sketch as-is, I'd be happy to hand over the code for my usual $50AUD. If we are going to need to make a bunch of changes to accomodate your LCD or to do a bunch of things you hadn't realized you were going to need, then we will have to work out how long that's likely to take.
http://paulmurraycbr.github.io/ArduinoTheOOWay.html

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