I would ask for review of our first project and we have couple of problems.

Other Hardware General Electronics
1

Hello, we have build our first arduino project that simulates audio signals on leds. Project is allready installed in the car but we want to improvise it.

Schematic can be found here: https://circuits.io/circuits/1547536-car-rgb-color-organ-project
Or here is image cause this site is slow:

Code can be found here: GitHub - alanaasmaa/RGB-Color-Organ

Our main problem is that we get about 0.5V from our aux cable and it makes noise. How can we elliminate this problem ?

If there are some other mistakes please let us know.

R1L, R1R = 200 kohm
C1L, C1R = 33 pF
C3L, C2R, C4L, C4R, C3R, C2L = 0.1uF
R2L, R2R = 22 kohm
R330/, R1, R2, R3, R4, R5, R6, R8, R9, R10, R11, R12, R13, R14 = 330 ohm
R10K, R10K/1 = 10 kohm
IC1, IC2 = ULN2003A
R16, R17 = 10 kohm
R15, R7 = 20 kohm
c100nf = 100 nF
ICLeft, ICRight = MSGEQ7

2

I think you have a far worse problem; you're feeding 12V directly into a pin of the micro when you close the main switch.

3

Oh actually the main switch cuts VCC from everything. Didn't notice that it was wrong on scematic.

4

Our main problem is that we get about 0.5V from our aux cable and it makes noise. How can we elliminate this problem ?

What aux cable? You haven't explained how this is connected externally - but I guess you are
breaking into line-audio signal?

If you are switching lots of LEDs without any decoupling capacitors I'd expect to pick up
noise on an audio signal just from your ground loop. You need a separate analog ground to
break up the ground loop I think, or at least some careful analysis of how your grounding
is actually arranged and making sure its star-grounded.

You could try pseudo-isolating the MSGEQ7 rails from the digital rails with back-to-back diodes and hope
that's enough voltage wiggle-room (about +/- 0.5V)

5

First of all here is the picture of the project. I don't know if it helps but hope so. Imgur: The magic of the Internet

MarkT:
What aux cable? You haven't explained how this is connected externally - but I guess you are
breaking into line-audio signal?

Aux cable that is soldered to the circuit goes to the stereo via splitter and the other end of the splitter goes to the phone.

On the schematic you can see that there are two 3.5mm inputs at right side. One goes for stereo and one to the phone.

MarkT:
If you are switching lots of LEDs without any decoupling capacitors I'd expect to pick up
noise on an audio signal just from your ground loop.

You mean something like these ?
https://www.google.fi/search?q=capacitors&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiesv_h8o_RAhVYNFAKHT3GDvwQ_AUICCgB&biw=1920&bih=960

Our voltage comes from car battery to 5x of these:
http://www.ebay.com/itm/5X-LM2596s-DC-DC-Buck-Converter-Power-Supply-Step-Down-Module-Voltage-Regulator-/162034869001?hash=item25ba07e309:g:RhcAAOSwiylXC1ke

1x is turned to 5v and voltage goes to circuid board. Then other 4x are splitted evenly for the leds and tuned to 12v. But all these voltage requlators are connected to each other in parallell. Except positive out. Led get his grounds from uln2003a that is on the circuit.

MarkT:
You need a separate analog ground to
break up the ground loop I think, or at least some careful analysis of how your grounding
is actually arranged and making sure its star-grounded.

Do you mean i have to seperate analog ground from digital.

MarkT:
You could try pseudo-isolating the MSGEQ7 rails from the digital rails with back-to-back diodes and hope
that's enough voltage wiggle-room (about +/- 0.5V)

So i have to but some diode between MSGEQ7 and ATMEGA chip ?

6

Pump

7

When you post links please use the chain link icon on the toolbar to make them clickable. Otherwise we have to copy and paste the URL to visit the link. That's not so hard but you want to make it as easy as possible for the people trying to help you.