Hi everyone!
I recently bought the ARDUINO ONE, and im triying to make a vumeter, combined with a led cube of 3x3x3, ok so the problem is:
im using a Jack for the input, this thing has 5 outputs: one for gnd and the other 4 are for the Rio-out & Lin-out, this outputs are connected to two 741 and the output of these two are connected to the arduino's a0 and a1 analog inputs, but i can't really make arduino read the values from the 741s so the led can turn on on the music.
this is frustrating maybe I'm doing some wrong connection, ,that one is the 741, and the jack is https://scontent-mia1-1.xx.fbcdn.net/v/t34.0-12/13652766_1071704779563317_309318595_n.jpg?oh=911b3fa42b0b1b4c02b4d2417c46a76b&oe=5787E6CC
I hope some can help me, I dont know if the info is enough, I'm noob by the way
Try the Analog Read Serial Example to see if you're getting readings before trying to activate LEDs.
this thing has 5 outputs: one for gnd and the other 4 are for the Rio-out & Lin-out, this outputs are connected to two 741
There are a couple of possibilities. Do you have a multimeter? You could check the connections with a mating plug and a multimeter.
Otherwise, you need a datasheet for the connector...
There are a couple of possibilities:
It could be a regular TRS (3-conductor) connector with a couple of extra ground or mounting pins.
There is a connector with a couple of extra connections to pass-through the sound to speakers. When you plug headphones into the jack the connection to the speakers is broken so the sound only comes out of the headphones.
It could be a TRRS (4-conductor) connector with an additional contact for a microphone. Again, there may be an extra ground or mounting pin.
Without a schematic I don't know what the 741s are doing. Is that in input or an output? What's that circuit board?
I use op-amps to make a [u]peak detector[/u] for my lighting effects, but I doubt that's what you have.
For a line-level or headphone-level signal you don't need an amplifier. If you're using a microphone, you need a preamp and a 741 could be used for that.
You do need to [u]bias the Arduino's input[/u] (2 equal-value capacitors and a capacitor) because the Arduino's ADC can't read the negative half of the AC audio signal, and it can actually be damaged by negative voltages. With the input biased at 2.5V, the silence will read about 512. You can subtract-out the bias in software if you wish. (With a peak detector, you don't need the bias.)