Help: Using an Arduino Uno as a 0-5V analog source to power up a RGB Led stripe.

Hi everyone, so basically I made a short Python code to scan mi screen, get the average RGB value, and send it as a 4bit binary number to the arduino (going from 0 to 254, using steps of 16).

So far I have 12 arduino digital outputs. For every color, I made a DTA conversor using an op amp, so every 4bit color has now turned into an independent 0-5V analog voltage source.

The LED stripe is formed by sixty 3 serial leds.

My question is how do I go from 0-5V to 0-12V to plug into the stripe. Maybe some kind of MOSFET? I'm pretty new to electronics, so any kind of schematics would be highly appreciated!.

Thanks.

Hi,

You can not fade leds with an analog voltage. An led is not like an incandescent light bulb. An led's brightness does not change linearly with voltage.

To fade an led you must use pulse-width modulation (pwm). This is a square-wave signal with a frequency high enough so that it does not appear to flicker to the eye. Fading is achieved by varying the percentage of the cycle that the signal is high versus low.

You will need only 3 Arduino outputs for this, but they must be pwm capable outputs. You can drive transistors directly with these outputs (no op amps required) to switch the 12V supply to the led strip on and off.

Paul