Need some help assembling a roller blinds automation project

Hello all. beginner here, in need of general assistance bringing this little project to life.
So I have regular roller blinds at home and I want to make them button controllable by adding a motor at the bottom, mechanism is less relevant rn.
The plan is to use this 12v 1.1A (stall) 23 kg.cm 14 rpm dc motor with with this L298N driver and an Uno/Nano.
The main question is; what is the best way to supply power to all that?
I have a 12V 1A ac/dc adapter.
I thought of either just connecting to them both with a dc connector, but I'm not sure how will that affect the voltage and amperage.
Another idea was to connect the Arduino to the power supply and the motor to batteries, however I don't know if that'll be able to supply the current the motor needs. This machine will work very little, like probably a total of 30 secs a day.
Any help is appreciated. Thanks!

A few tips..
Search for Arduino and blinds. Several topics like that exist.
Drop the dinosaur L298 and go for modern MOSFET based drivers.
If You can use mains and good power supplies that will save You from difficulties.
Do think about the mechanic parts needed.....

Pololu has much better motor drivers than yours.

Actually, I suggest just using a relay(s).

842996

Use cct. G3 or D3.

A 12V 1A supply will work nicely.

Thanks for the replies.

Where I live there are not many components readily available so I think the best there is around for a fair price.

Could not understand...

Just in parallel?

thanks guys

“I have a 12V 1A ac/dc adapter.”

That’s all you need.

Get two 12v DPDT relays and use circuit D3.

Two 2N2222 transistors will work for this.

If the Arduino isn’t power anything from the 5v pin 12v into the Vin pin will be okay.

Wow I got nothing... guess I have some homework to do.
Thanks

Please explain what you are saying ?

I could not understand you.
Sorry English isn't my main language as you have probably noticed

@LarryD @Railroader
Hi guys. so I tried improving things after your replies.
I thought about this MAX14870 driver with a relay. What do you think?
Also, what's practically bad about the old L298N driver?
Thanks.

These are BJT output so the voltage drop is significant, poor efficiency.

image


MOSFETs are better and more efficient in power.
They have better current protection circuitry.


Since you only use the circuit for short times, IMO 2 relays are definitely an option.

https://www.jameco.com/z/DS2E-S-DC12V-Panasonic-1500V-Surge-Withstanding-Miniature-Relay_842902.html

Thank you for your reply.
Do you mean to use the relays like in the diagram?
I'm new to relays.
Also, the one you linked is not available where I live. What should like in my relay? How about this one?
And why does the one linked has 5 legs?
THX

Yes that circuit will work.


You will need 2 NPN transistors to pick the coils.

Add the kickback diodes as shown in the schematic posted earlier, i.e. circuit D3.


Page 3 shows the pins of the relay you picked (SPDT).

2 pins for the coil, 3 pins for the contacts ( NC, NO and C ).
https://www.mouser.co.il/datasheet/2/307/en_g5le-1131193.pdf

Can you adjust the speed with the relay based circuit?

No.

The OP’s motor is slow:
12 V brushed DC motor combined with a 377.93:1 metal spur gearbox.

1 Like

Hey, thanks again.
How about this circuit?

Everything is powered by a 12V 1A AC/DC adapter.
The two buttons are to control the motor's direction with the code I'll write >> the Arduino will send voltage through digital pin 12/13 depending on which button was pushed >> the Arduino will activate the relevant relay >> relay will activate the motor in the desired direction with that H bridge.

Also you haven't commented anything about this driver. It's seems super simple, anything bad about it? Thank youuu

p.s I want an Arduino so that it would control limit the roll according to blinds limit.

Note: the relay pin numbers in the above schematic have to be changed to match your relay pin numbers.

Ohhhhh OK now I understand the schematic that you have posted earlier.
Thank you very much, you are very helpful and kind.
What did you mean to explain with that last diagram though?
Except than the pins of the relay, do you think my circuit is good? and how about the relay I chose? I could go for another one, that specific one was simply available and relatively cheap.
Again, thank you.

This might be of some use. You could refer to it. Instead of using google assistant just wire the motor to the button.

The schematic in post #16 shows you what is needed to get your circuit to work.

Since the Arduino is limited in the current and voltage it can provide, relays need a transistor to drive their relay coil.

Coils require a kickback diode to snub out high voltages when the coils de-energize. That is why you need D1 though D6.

You should include limit switches that physically operate when the blinds reach the fully open and fully closed positions.

The pin numbers on my yellow relay components may not match the relay you purchase so you need to renumber my relay schematic pins.

Your motor and relay coils need to be 12VDC as seen in the schematic.

I actually just meant for the Arduino to be limiting this by counting the turns.

Are you sure? because the coil's voltage is 3V and current is somewhere under 150mA, which are within the Uno's output range.
The datasheet