Arduino and RGB led strip

Projects General Guidance
1

Hello,
This will be probably really trivial for you but i have big difficulties with it.
I would like to control RGB led strip with aruino. I found one realy nice project that i want to use.

But i want to add switch before power supply to control turn on or turn off light. I need to have information about state of that switch on arduino.
Power supply has output voltage 12V. I need to reduce it to 5V for arduino.
I found nice tutorial how to do that.

So i will probably need to add one 10 kohm and one 15 kohm resistor.

So my output voltage will be 4,8V. Can i directly connect that wire to arduino input pin? Is it safe? What about output current from power supply 12,5A?

I will be happy for all your answers.

PS: i dont have a lot of skills with electrics and arduino.

Sorry for my bad english.
Thank you.

2

The voltage divider should make the voltage safe for an Arduino input.

3

Did you wire your circuit exactly as in the picture. If so, note that the red mosfet is the only one wired right. On the blue and green the pulldown (10K) are to the drain terminals, not the gate terminals as it should be

4

First thank you for your answers.
I wire all mosfets like red one. It is working perfect.

Problem is with that voltage divider. When i wire it like on the picture output voltage is not constant. It is oscillating around 0,7-3V. I don't know why. That is problem for arduino input pin.
Can you help me with that.
Thank you.