I’m very new to all this stuff and I’m normally much more on the Software than the Hardware front .
I want to measure the Voltage going to my Speakers and then control some LEDs with it, just like that simple
trick when you connect an LED to a speaker wire, just without the LEDs or the Amp getting blown up
I want an Arduino inbetween doing all the processing stuff with it acting as LED controller.
Soo… After some researching in the web I came up with the totally scientific drawing that’s attached to this post.
It’s a bit chaotic, but the idea seems simple enough: Read Speaker Voltage via Analog Input, do some processing stuff with it (I’ m not concerned with Software atm) and output the result individually to the Red, Green and Blue LEDs in the strip.
So these are just three MOSFET controls, one for each color.
Now, onto the stuff I can’t figure out. Like the bit for measuring the speaker voltage. I know so far I could measure a Voltage of up to 5V, and if it gets any higher, I’d use a voltage divider circuit.
So, my questions are:
Where do I connect Negative (or “null”, as I understand it is with AC) to the arduino? I get that voltage is measured by the difference between Ground and the input, but the ground wire from the PSU is DC, the Speakers are AC, which brings me onto the next question:
Is it OK to combine AC and DC circuits like this? It just seems wrong to me. Can the Arduino accept an AC input into the Analog pins?
Oh, and last: Is a 10k resistor between every PWM line and the ground really necessary? As is my understanding the gate will just turn on and off randomly if it gets loose but does that do damage other than a wildly flashing LED?`
Thanks in advance for any assistance on this.