Converting low voltage into pwm with Arduino Micro

Projects General Guidance
1

Hello! I am considering an Arduino Micro for a project I want to complete but I've never used anything Arduino before and I need some help understanding if this is within it's capability.

I have a DC 0.0 to 0.7v+ signal which I want to use to control the brightness of three LED strips which will draw about 1-2A at 12V each.

Can I convert my 0 to 0.7V into a pwm signal that goes from 0 to 100%?
Can I do that with three channels at once with the micro? (I have three separate 0-0.7V signals)
Can anyone recommend how I will go from the output of the Arduino to drive 1-2A of LEDs at 12V with the PWM signal?

Incase you are curious, I intend on taking the output from a VGA port's red, green, and blue signals, which varies from 0 to 0.7V to control the intensity of each color in each pixel. I'm going to connect the PWM output from the Arduino to red, green, and blue LEDs. Now when I'm playing a game, an explosion would make the whole room light up, and a music visualizer could flash the lights to the music perfectly in sync. I will also be able to use it as a much better version of RGB lightbulbs which always leve me wanting more control than they allow.

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1/ Read your 0..0,7 volt signal with analogRead - for best resolution set the reference to 1.1V.

There's only one a/d, which is switched to different inputs , so the readings you get will be about 100uS apart..

To drive your LED's you'll need some logic level MOSFETs capable of handling the current.

You'll also need some current limiting resistors to avoid damaging things..

Note - the bandwidth of a VGA signal is FAR FAR greater than the arduino a/d can handle - all it can do is to take an average - is that good enough? If so I should add a low-pass filter at about 30Hz - to average over a frame.

regards

Allan

3

Thank you!

Logic Level Mosfet was the search term I was missing. I was looking at plain mosets knowing I was in the wrong place but not knowing where else to look.

I plan on using a capacitor and resistor to smooth out the constant voltage changes created by VGA, not sure if that equates to a low pass filter but it'll be easy.

Averaging over a frame or two is my plan so I don't need a very high resolution.

4

Hi,
What is the application, what is supplying the 0 to 0.7V?

Thanks.. Tom... :slight_smile: