The problem i have run into is position accuracy.....
I've tried just about everything, or at least contemplated it. Anyway my current issue is that i want/well need in this case because the torque required is far past what any normal stepper can handle., i need to control the position of a dc motor. What my intent is that i can have a stationary drive DC motor for the roller shade and a stepper motor on the opposite end. The steppers job is not to apply any force, but to feed the arduino with the number of steps taken. EX: I specify that at 20000 steps, set "motorPin = LOW" or whatever syntax allows......or how about this, once the stepper reaches a certain amount of steps it will then shut the DC motor off.
SO my problem is that i cant seem to figure out how to READ step data instead of powering the stepper to do work.
PLEASE PLEASE internet geniuses, show me the light
I hope this won't be perceived as hijacking this thread , but I'm planning to do the same project.
I'm getting roller shades, and the seller usually automates them with Somfy motors and controls. However, they're charging me like 450USD just for each motor...
I have light experience in arduino but I'll learn online if needed, what I need to know is if the hardware I need does exist, or if I need something else
I found this badboy on ebay, has like 80% more torque than the one needed ]
I have an arduino duemilanove but ideally I'd like to use a Nano to save space. What I need to know is what shields/stuff do I need to drive that motor? I have a relay which would easily allow me to turn it on/off since I can input/output any voltage to the relay, the problem would be how to reverse the rotation? That motor supports reversal just by swapping the polarity, but I couldn't do that with the relay... additionaly I'd need to calculate the degrees the motor has rotated, so I'd need some high-current motor shield... or another way to stop the motor when the rollerblind is fully open/closed
At least there are others.......but i've been working on this project for 2years.........my mind is exhausted and my walls look like swiss cheese. Trial and many many many error at its finest. I first started with a motor winding a cord for venetian blinds -fail, then moved onto roller shades, started off with the cheap walmart vinyl ones problem, i only had dc motors... and if you do a time delay for position control, by the 5th use so many inconsistencies had piled up it was saying half way was the bottom and 3x around it self was the top.....so a result in a fail.....then i was like all i need is some beefy steppers, they worked flawlessly even with my nicer and heavier IKEA roller shades.....problem, every time they ran it was like a jackhammer in the wall that echoed about the house, and this is a sizable house. so annoying once again resulting in yet another.......fail......so here i am once again at square one hoping that the quiet but powerful DC motors paired with an encoder will be the answer to my problem.....so if you have any sort of question about the process, feel free to ask, Id love for atleast one person to come out of this alive and well
mikeg5098:
That is what i originally wanted to do but i have heard they can get a bit in accurate, is it true?
Seems unlikely given the fact that the ones in my printer give it 600 dots per inch resolution. You do understand that you cannot always believe what you read on the internet?
, but I'm planning to do the same project.
