Multiple LED Strip sections with 1 arduino

Good morning,

i hope that someone can help me out. I have a 4 pin rgb led strip and want to cut it into 5 LED sections.

Those sections only need to turn on/off/fade individually(5 leds at a time) but should all have the same color.

What would i need to get, for something like that to work? Maybe shift registers and mosfet? would this work together? How would i address each section?

Thanks for your help!

Dennis

You need a FET or bipolar transistor for each colour on each strip. Then you need a PWM signal on each of the transistors. You could do this with a PWM board from Adafruit.

However much cheaper and simpler is if you used addressable LED strip then it can all be one strip and you would not need any extra hardware apart for a resistor and capacitor.

thanks, yea i still have like 100 meters of that led strip laying around.
WS2812 are a little expensive when it comes to that..

With FET, do you mean like a MOSFET?

Thanks,
Dennis

Yes.

It's not possible to turn on and off or fade "the same color" because bright-blue is a different color to dark-blue. There's no way of mixing them independently without having three FETs per strip.

gotcha, so would it be possible to have 1x74HC595N talk to 6xMOSFET and 2 strip sections?

Well there won’t be much time for your Arduino to do much else as the PWM must be refreshed quickly.

For example suppose you want to have a PWM frequency of 100 Hz and have an 8 bit resolution then you have to have an update frequency on the shift register of 100 * 256 = 25.6 KHz.

If you don’t like the hardware soloution then look for a soft PWM libiary to turn any pin into a PWM pin.

thanks, nah there will not be anything serious going on. Just some slow fading and maybe a chaser of the sections. Would this be something the arduino can handle?

a chaser of the sections

Not sure what you mean.

Put it this way, the way you are proposing to do the project is something I would not consider at all.