Roller Blinds - WTF


(Martin Bailey) #1

So ive been on the smartthings bandwagon for a few months , and for some reason the one thing that seams to be beyond me is roller blinds , I have found lots of sketches etc. for regular blinds, but Im really struggling with roller blinds , mainly because I have hacked my servo to be continuous and what ever I try to do … every bit of code ive touched gives me the problem of the servo having fits when it goes over 90 degrees. Has anybody had any success with cobbling together a solution. Dan as ST_Anything has been a great starting point, but again … from 90 - 180 goers one direction 0 - 90 goes the other … great, but really struggling to get my head around it. :smiley:


#2

Why not get a continuous rotation servo?
http://www.amazon.com/American-Robotic-Supply-Continuous-Rotation/dp/B01MSAIL3D

Also, your programming for a continuous servo is going to be different than for a limited rotational servo. You realize that right? The only way that you’re going to get it to work is to run the motor for a set amount of time and hope that it lands in the right spot. For this type of job a stepper motor is better because you’ll know for sure how far you got.


(Martin Bailey) #3

Hi Ryan ,

Thanks for the question , tbh , I am pretty new to the whole experience , so possibly im just digging myself a large hole , I have some stepper motors and some servo’s I was originally going to do this with Home Assistant and MQTT spurred on by Ben from BRUH Automations video, however I found Dans ST Anything and this made me realise that there was still a lot I could do in SmartThings without having to do things elsewhere. So in answer to the question, its what I had … and I needed the torque , so it possibly is something I could change if it would solve the problem.


#4

Well, how are you commanding the servo to run? You’re not just initiating a setting of 0-180 are you? Because continuous servos work differently. Usually a setting less than 45 will run it in one direction and a setting over 135 will run in the other and a setting of 90 will be stationary.

You would have to use either timing or some other sensor to shut the motor off. Now, if you’re using ST_Anything you can have a callback function to turn the motor off when it hits a certain point if you have a wired contact sensor, for example.

You could wire two contact sensors, one at open and one at close and then attach the magnet to the roller blind. That way you’d know when to shut them off.


(Martin Bailey) #5

ive already readjusted the pot and removed the end stop on the servo Ryan … essentially turning it into a continuous servo , I didn’t just put a regular one on there and hope for the best :D, and yes … I know its going to have to be coded differently , so just really not sure which way to go at the moment, I have been looking at various ways so im thinking of the fact that i would need to run 90 - 0 or from 91 - 180 for a set period of time to get the result i want


#6

Sorry, hit post prematurely. Check my previous post and the idea on contact sensors.
Also, if you do decide to do anything based on timing, i would suggest doing it inside your sketch because the ST timing isn’t going to be reliable enough to get them open or closed the way you want.