I need to have full control from PC of 24 RGB LED's

Hey guys,
so I'm total new and made some research already but first let me explain what I want to do:

I want to have full control of 24 LED's from my computer with an Rs232. If I click a bottom on my screen I want one precise LED to go on and the color that I want should also be a choice on the screen.

What I found in my researches is that I need one MAX220 for the Rs232 to go from the PC to my Arduino uno and maybe a PCA9635 I2C IO Expander or TLC5940 to control more LED's.

Or skip the RS232 and use a USB to Serial interface. Or if you grab a Uno or a Nano that’s already build in.

The PC application you have to make yourself in any language you like. But it’s not Arduino related…

What driver you use for the LED’s is up to you… What led’s do you have? The PC9635 can sink 25mA (but only source 10mA so I wouldn’t use that) which is fine for a single normal led. It has no current control so you need external resistors per led. The TLC5940 can do more (only sink) and had current control. You only need 1 resistor per IC. But you have to watch the heat production of the chip then.

But there are many more…

I need the rs232 that’s why I can’t skip it.
Can recommend me an application?
I have some normal RGB LED’s with 3 pins.
Which ones are good to do that?

I need the rs232 that’s why I can’t skip it.

Then you might want to explain why you need that…

Can recommend me an application?

No, it’s a pretty specific task so I guess you have to write your own.

I have some normal RGB LED’s with 3 pins.

I hope you have some more data… It’s like telling me you have a vehicle with 4 wheels…

Which ones are good to do that?

No idea, depends on what you want to do EXACTLY.

Make your life simpler. Get some ws2812b leds. No driver chips needed. String them up and control them using a single Arduino pin.

Yes, Neopixel (WS2812B) strip, any Arduino (Promini if you want small) and a decent 5V power supply.
Full white needs 60mA/RGB LED * 24 LEDs = 1.44A supply needed.

There's a link to an Arduino library on the page as well.
Browse around, or ask about other WS2812B options if a fixed strip is not what you're after.
Here's a good 4A supply.

Well, maybe a Nano if you want USB connectivity all the time.

Ok I'll explain it better.
I have here a box who has 16 buttons with each button I can switch between things like programs who go to satellite an each button has 1 LED except 4 which have 3.

But the pieces to do that are quit expensive so we had the idea to do the same thing but with arduino.
And to start with I got the Job to have control over the LED's from an PC with Rs232.
We will keep the buttons only for the new box.
sorry for bad english if you have any questions you can still ask

Still not clear... Still no idea why RS232... What box? Photos? And satellites, huh?

16 buttons with 24 leds I get, but sounds to me like you want to mimic a commercial product?

Okey I'll ask about Rs232 later I don't know either maybe USB is fine as well, I'll let you know later.
This is the box I'm talking about with the buttons and it is our product but we want a cheaper way to
create it. The box has Rs232.
Its for a Broadcast Center that's what I mean with satellite.

Sorry here it is

Alright, but then you should have more specs about that "broadcast center". Just giving it RS232 will do nothing if you don't know how to talk to it. Or, how it's talked to. So more specs.

That is something I don't know because I'm just a student here and not really working here .
I'll ask him soon

You should do that. Because without knowing the specs you can't design a system...

So key question here WHAT is going to control the leds. (The computer is NOT the answer here :wink: aka, what software? Written by you? etc)

I spoke with him and it's clear now, Rs232 because of the lenght because USB only goes over 2m.
Software is writen by us so no problem there too.
The box that I showed you is also virtual on our software so if we press the button the LED goes on inside the box and these led's need to be 24 single RGB which I can sode so I probably need a chip to controle them?

RGB with 3 pins.

Pics please.

Mm, don't know if I would use RS232 to overcome length nowadays... RS485 is way more robust. But anyway, just add a RS232 (or RS485) driver on both side and be done with it. Although I don't get why you would put a controller for a piece of software more then 5m away from the PC....

But question, how are the buttons connected now? Seems a bit weird to use a different interface and controller for the buttons and the leds...

Next step, get the protocol that the "software written by us" is sending out :slight_smile:

And as for the leds, just pick one of the drivers out there. WS2812B is nice but if the leds are already in teh buttons that's a problem. Which driver to pick is on you. If each led is just a regular led there is no limit because of current. Never worked with the PCA9635 so don't know about the library support for that. The TLC5940 is a bit weird to control (because you have to send the PWM clock as well) but works just fine with a library. That's all I can say about it.

And ow, 24 RGB leds, that's a bit different. That makes for 72(!!!!) leds. That is A LOT of wiring...

PS USB does 5m :wink:

How about these?

They look & mount like regular 5mm LEDs, but you can wire them up in a string, +5/Gnd in parallel to all and then just data out to data in on the next LED.
Have a promini with RS232 adapter (male or female connector needed?) receiving a burst of 72 bytes to pass to the LEDs using the Adafruit neopixel library for WS2812s.

Do you need the full range of colors that PWM supplies?
Or just the 8 basic colors that having the 3 LEDs full on or full off can provide?
3 full on = white
all off

Sorry for not answering for a long time.
I got more information now.

There is my software, if I click the button 1 on my box it sends a code like 1001 and it shows me on the software which button is clicked by getting red, same thing the other way around.

There is also a remote protocol.

Well that’s how it works without the arduino, and to do it with the arduino to control the 24 LED’s I have SN3218 two times here.