Need some help assembling a roller blinds automation project

In post #16, the relay coils are 12 volts not 5 volts.

Do not drive your relay coils directly with Arduino pins.

An Arduino output pin can safely supply 20mA.

For the Arduino to count turns, you need to have a sensor.

What do you mean by that?

Count based on turning time in some direction.

If you try to take more than 20mA from an Arduino pin (example your 150mA) you will destroy your Arduino.

You can time events with the Arduino, however, this is not the same as counting turns.

Suggest you also keep the limit switches as a fallback.

Why is that? Everywhere I've read online states it can output 133mA and can certainly turn on relays.

But I do know how long a single turn takes, and how many turns it takes for the blinds to go from top to bottom.

With your suggestion; using transistors, relays and limit switches, Is an Arduino needed?



20mA is the value that can safely drawn form an output for an UNO.

You are the one who suggested timing. You need to apply power to the motor and time how long it takes. You need to time the number of turns.

For accuracy, a sensor wheel needs to be attached to the motor shaft and use an optical switch or physical switch (a limit switch would work) to detect one revolution.

Well if you want to open and close at a specific time of day it makes sense to use a controller. An RTC could be added and would tell the controller the time of day.

This is your project, it’s incumbent on you to design how you want things to function.

We give you the reasons why you should do things correctly.

Ignoring said advise will result in your failure.