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Topic: Beginner needs help with music organ/spectrum. (Read 4534 times) previous topic - next topic

Grumpy_Mike

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Is this okey ?
No.
There is nothing to limit the current in the LEDs and what are these switches?

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I think i need 18 FETS becose led strips needs 12v.
Why is the number of LEDs dependent on the supply voltage?

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I'd like to get 6 strips and every strip has 3 colors. So 6x3 is 18.
You only need a separate PWM output for every different control you need. You only have 7 channels for each audio channel, therefore you can not possibly need more than 14 PWM channels. If you want to drive two strips with the same signal then simply connect the same PWM signal to each FET or transistor driving that chip.

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Also what would be best way to make car battery stabilizer.
Is this a battery in a car that is working? If so this is very tricky. Normally the battery would be being charged at 13.6V but it can also surge up to 15V with higher spikes. When the car is not working you might get anywhere between 12.5 and 11V depending on the state of the battery. So getting 12V is hard because a regulator needs a few volts more on the input than it's output is going to be.

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And is it okey to run whole system with 12v
Yes it is but take note of the above.

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Maybe with fuse.
A fuse will normally blow way after any electronics it is trying to protect has meted.


thsamog

First of all you are AWSEOME for helping me so much !

No.
There is nothing to limit the current in the LEDs and what are these switches?
Yes i know that part is not yet done. I havent figured out how would i do it.
I was thinking about that you can switch every led off and on. Actually i should make it inside code somehow.

Why is the number of LEDs dependent on the supply voltage?
Sorry i didnt understand the question. English is not my main language.

You only need a separate PWM output for every different control you need. You only have 7 channels for each audio channel, therefore you can not possibly need more than 14 PWM channels. If you want to drive two strips with the same signal then simply connect the same PWM signal to each FET or transistor driving that chip.
I love your brains. I have to think more out of box. Clever !

Is this a battery in a car that is working?
Yes it is.

So now i have to figure out stabilizer and how i get leds connected.

Grumpy_Mike

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Sorry i didnt understand the question. English is not my main language.
You said:-
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I think i need 18 FETS becose led strips needs 12v.
[English lesson]
That says because you have 12V you need 18 FETs. That is saying there is a relationship between the voltage and the number of LEDs. Clearly there is not.
[/English lesson]

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I was thinking about that you can switch every led off and on.
I thought we had established that you were using strips, you can not control individual LEDs when they are on a 12V strip. The strips wire up the LEDs in groups of three in series and one current limiting resistor. That is how they work off 12V. You need to switch the ground pin for each colour to turn that colour on. This is best done with a logic level FET. The FET is switched by putting the PWM output on its gate pin. See:-
https://learn.adafruit.com/rgb-led-strips/usage

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So now i have to figure out stabilizer
It would be much easier if you didn't use 12V, as it is you need to regulate arround a voltage that could be above or below the voltage you want. The only way to do that is to use a buck/boost regulator circuit, at that power these tend to be expensive and they are not circuits you can make yourself because they need proper layout in order to be stable.

thsamog

#18
Feb 02, 2016, 01:00 pm Last Edit: Feb 02, 2016, 01:55 pm by thsamog
It would be much easier if you didn't use 12V, as it is you need to regulate arround a voltage that could be above or below the voltage you want. The only way to do that is to use a buck/boost regulator circuit, at that power these tend to be expensive and they are not circuits you can make yourself because they need proper layout in order to be stable.
Is there better way to implement this system into car ? I was thinking that would the currency be stable if car is not moving. It's not even legal to make you car a discoball. Or is there any simple way to make it more stable.

Also i updated my circuit https://123d.circuits.io/circuits/1542618-car-rgb-color-organ-project

I used your tip for 14 FET's, do you have idea how i could implement these missing 4 Red inputs of LED strips?

Grumpy_Mike

#19
Feb 02, 2016, 02:42 pm Last Edit: Feb 02, 2016, 02:45 pm by Grumpy_Mike
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I used your tip for 14 FET's, do you have idea how i could implement these missing 4 Red inputs of LED strips?
Missing 4? You have still not got it. There are a missing 8 PWM signals.

There are only 6 pins on the Arduino capable of PWM,  to get more you have to use this library:-
http://forum.arduino.cc/index.php?topic=19451.0

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Also i updated my circuit https://123d.circuits.io/circuits/1542618-car-rgb-color-organ-project
Those LED strips are wrong. You have drawn then as common cathode RGB LEDs, where as in fact your strips should be common anode strips. They should also be strips not individual LEDs. I know what you are going to say, that the program doesn't have that part, so you will have to make your own part and if that is not permitted abandon that package and draw with pen and paper. That is the MAJOR trouble with schematic software package, if you do not use the correct symbol then people can't follow what you have done.

You have to decide what strips to connect to what drivers, you only have 14 different signals of data so you can not drive each strip you have independently because there is no data to drive it with, so....
You have to decide how to distribute the 14 data channels over your 18 strips / colours. That means 4 of these have to be common with one or more of the 14 you already used. You have to make that decision as to which.

Each FET needs a 150R to 330R resistor in series between the gate and the Arduino PWM pin, and also a 10K from the gate to ground. Let's get the design right first before you worry about powering it in a moving car.   

thsamog

Missing 4? You have still not got it. There are a missing 8 PWM signals.

There are only 6 pins on the Arduino capable of PWM,  to get more you have to use this library:-
http://forum.arduino.cc/index.php?topic=19451.0
Yes i allready found that. Also i found this one https://github.com/elcojacobs/ShiftPWM Whats the difference between these two ?

Each FET needs a 150R to 330R resistor in series between the gate and the Arduino PWM pin, and also a 10K from the gate to ground. Let's get the design right first before you worry about powering it in a moving car.   
https://123d.circuits.io/circuits/1547536-car-rgb-color-organ-project/ Is it looking better now ?

How can i thank you with all this help ? I just rep+ every post ! :)


Grumpy_Mike

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Also i found this one https://github.com/elcojacobs/ShiftPWM Whats the difference between these two ?
That is for using shift registers, you need to have a chain of shift registers and this will generate PWM on the outputs. This is way more CPU intensive and requires more hardware in your case 3 shift registers.

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Is it looking better now
No you have the resistors wrong. The 10K should go from the gate to ground. These should not be two resistors in the gate, there should be only one, whose value is between 150R to 330R. That R means ohms not K ohms, the 4 red LEDs are still not connected up.

You have all the gate resistors going to the same place, each one should be connected to a separate PWM pin.


Schematic is starting to look a bit messy, try and separate the wires more so they are easier to trace and not over one another.

thsamog

#22
Feb 03, 2016, 06:38 pm Last Edit: Feb 03, 2016, 09:00 pm by thsamog
Schematic is starting to look a bit messy, try and separate the wires more so they are easier to trace and not over one another.
Yes i noticed. This webpage is annoying with wires. But im not at home and i dont have right equipment to draw these things. But i did my best is it looking better now ?

If there is a change that you have account tho this website i can give you permission to edit.

But here: https://123d.circuits.io/circuits/1547536-car-rgb-color-organ-project

It seems that this site is not very good with larger project's. It starts lagging like hell.

EDIT: These wires went again on tom of each other.

Grumpy_Mike

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But i did my best is it looking better now ?
Yes you seem to have got the FETs and resistors right now.

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It seems that this site is not very good with larger project's.
You mean "projects" no apostrophe required for a plural ( sorry my wife is an English teacher )

I would agree, I have only come across it once before and I find it very difficult to navigate on my Mac. It seems that the touch pad gestures are all wrong compared to how all other applications work.

I just use a generic 2D drawing package ad group component symbols so I don't have to redraw them from scratch each time. Using a ground symbol and a supply symbol will make the circuit look a lot neater. Also a good tip is to have the ground down and the power up on the page, that improves readability.

thsamog

Thanks for you help all ! I have ordered all components now. I start the code but i hade one more idea.

Is it somehow possible to calculate two outputs avarge into one without arduino.

MSGEQ7 gives me 7 outputs but if i would get 9 out by calculating
1 and 2 output avarge and 6 and 7 output.


Like he does: https://www.youtube.com/watch?v=C-h5eGZbqNs&feature=youtu.be
http://www.embedded.com/electronics-blogs/max-unleashed-and-unfettered/4439541/BADASS-Display-Coding-Competition

Grumpy_Mike

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without arduino.
What do you mean by this?
Yes you can do that with the arduino but why without.
You could also interpolate, that is put in an extra channel which is the average between two adjacent channels.

thsamog

My girlfriends teacher suggested us to switch to ULN2003 so we did.

It looks now like this:
https://123d.circuits.io/circuits/1547536-car-rgb-color-organ-project


What do you mean by this?
Yes you can do that with the arduino but why without.
You could also interpolate, that is put in an extra channel which is the average between two adjacent channels.
Now i didn't understand. But i try to explain my self better.
So as you can from picture i'f like to get O6 & O7 and calculate their avarge into LED 1 R.
Also for O1 & O2 into Led 3 R. And the same with other chip.
I can't use arduino becose no ports left.



Grumpy_Mike

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My girlfriends teacher suggested us to switch to ULN2003 so we did.
Your girlfriends teacher is an idiot and does not know much about electronics. That chip can only switch about 600mA at any one time.
See:-
http://www.thebox.myzen.co.uk/Tutorial/Power.html

and

http://www.thebox.myzen.co.uk/Tutorial/Power_Examples.html

thsamog

That chip can only switch about 600mA at any one time.
So its 600mA for one output or in total ? We are using two chips so its 1.4A for one chip. We have only 4m of leds. This is going into car so not very much. The actuall reason we switched was that school doesent had any mofset if im not wrong.


Grumpy_Mike

#29
Feb 09, 2016, 12:55 pm Last Edit: Feb 09, 2016, 12:56 pm by Grumpy_Mike
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So its 600mA for one output or in total ?
In total for one chip.
The limit for one output is 500mA but no more than a total of 600mA being sunk at any time.
Did you not read those links? That is what they said.

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We are using two chips so its 1.4A for one chip.
So that is way too much.

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The actuall reason we switched was that school doesent had any mofset
Well you should have said that before, it is well known that the laws of physics can be suspended by a school if only they fill in form "Physics Laws exception form number GzeroD"

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