I'm making an LED matrix wall, and so far my plan is to connect a Rextin 400W, 12V, 33.3A power supply to (6) WS2811 addressable LED strips (5 metres each, 150 LEDs per strip) in series. Normally, I solder the 12v wire on the strip to the DC jack on the Uno, but I'm worried about frying the Uno with this much power. Would it be correct to power the Uno from a 12V adapter and send the ground and data from it to the LED strip, then power the LED strips themselves from the transformer?
Also, I'm not sure how to connect the transformer...I'm not an electrician and I'm still pretty new to using Arduinos and LEDs, so it's a little scary to use such a powerful transformer. I've tried to find tutorials showing how to power that many strips with just a single power supply but haven't found it (other than Bitluni's LED matrix tutorial on youtube, but he doesn't actually explain how to wire the strips to the transformer).
If anyone has advice for this or knows of a good article/tutorial, please let me know. I want to be safe, but also minimize the amount of adapters for this project. Each strip is 45W, so I figured I would be using it at 75% capacity with 6 strips.
but I'm worried about frying the Uno with this much power.
Well the Arduino will only take the power it needs but with such a large current capacity it is very unforgiving of any errors you make.
The immediate problem is that your proposed set up has 1500 controllable LEDs in it and that is way more than you can control with a Uno. You simply haven’t got enough memory to hold any pattern. Also your frame update rate is likely to be in the order of a few seconds. In reality you have three times the number of LEDs but that sort of strip only lets you control then in groups of three.
A mega would have enough memory though, as you need 1500 x 3 = 4500 bytes of memory.
The power supply has exposed mains connectors so you need to fit it in a case where you can’t get access to them, and also be able to maintain the air flow through the power supply. Otherwise your assessment of what needs doing is correct, although some people would suggest you are better off using a separate regulator to supply the Arduino with 5V if it has anything else connected to it, drawing current as the on board regulator is on the limit of overheating as it stands with 12V input.
Ah good to know about the Uno! It never occurred to me it would not have sufficient memory. I'll get an Arduino Mega then.
Also good to know about the case, I definitely did not want to have the connectors exposed. So if I understand correctly, a voltage regulator would allow a consistent flow without the need to attach multiple voltage wires to the strips? Would this be an example? Is there anything that shows how this setup would look like? Again, I apologize but I haven't found a tutorial similar to what I am trying to achieve.
So if I understand correctly, a voltage regulator would allow a consistent flow without the need to attach multiple voltage wires to the strips?
No.
A voltage regulator is a small board or component that converts one voltage to another. In your case you need a 12V input with a 5V output.
You would use it to power your Arduino from the 12V power supply you posted in the original post. The Arduino has a built in voltage regulator but it is not mounted on much of a heat sink so it can easily overheat with anything over the normal current draw of the Arduino and a 12V input.
You could build a cover over the connectors on that power supply you showed.
However I am concerned that you are so far out of your depth at your current state of knowledge that you start off with an altogether smaller setup. That power supply will provide a frightening amount of current and one false move will melt wires or cause fires.
Yes if everything is correct it will work, but it is easy to get things wrong if you have little experience.
Many beginners make the mistake of trying to make something too big too soon.
It is not just a matter of connecting the power supply to the strip. The foil traces are way too small to carry the amount of current you need and you have to supply power and ground using thicker wires every half meter or so along each strip. Wire thickness and layout is a tricky subject with such high currents.
Scaling up in electronics, as in any other field, is another skill Step change.
For example imagine you make some bread for a friend, and then four supermarkets want to take bread off you. The scaling up process will be something you have never done before and you have to learn new skills.
Ah I see. I appreciate your concern and frankly I agree the room for error with such a high amount of power would be unforgiving. Also, I was not aware of the overheating risk involved with the Arduino, hence why you suggested the voltage regulator. I agree as well this is probably way too ambitious a project, considering my lack of experience with advanced electronics. I have learned a lot about wiring a reasonable amount of LEDs to my Uno, and installing a latching switch and tactile switch in projects but not something a big as this, especially with regard to voltage.
Well, a last ditch effort to salvage this project; would it be safer to use multiple 12v/60W adapters and amplifiers every 5 metres to avoid voltage drop? For example this amplifier?
would it be safer to use multiple 12v/60W adapters and amplifiers every 5 metres to avoid voltage drop?
I have never see one of these before and I can’t understand what it is supposed to do. All the reviews say they don’t work and the questions / answers say they don’t work with addressable strips like you have, so the answer would be no.
You could use multiple power supplies of a lower current rating and power each strip separately. Connect the grounds together but have the 5V to each strip to a separate supply wired at both ends of the strip. In that way you could just start with one strip and build up.
Ah yes I spoke too soon about the amplifier working with addressable LEDs. Yeah I wasn't sure about it since I recall a friend using them with regular analog RGB strips. I believe they simply connected the strips and allowed for additional voltage with a red and black wire you could solder to a transformer.
I'm a little confused about the setup you suggested...so wire the 12v from the additional power supply at the beginning of the strip and at the end of that strip, and wire the ground to the original ground from the first strip? Could I not just splice my 12v 5A adapter and simply wire the voltage and ground to the additional voltage and ground wires that came with my strip?
Like this diagram I've attached from the company?
Also, I am assuming a thicker guage wire soldered to the adapter and strip wires would be better for amperage handling? Like 14 AWG?
Could I not just splice my 12v 5A adapter and simply wire the voltage and ground to the additional voltage and ground wires that came with my strip?
No. You must never connect the 5V and grounds from individual power supplies together.
The grounds should be connected together or else it won't work. But if you connect the 5V as well the power supplies will fight each other and one will go bang.
The very thin power and ground traces on the LED strips drop too much voltage across them and this reduces the brightness and colour of the LEDs towards the end of the strip. If you wire the power to both ends of the strip then you half that resistance and it is a lot better. Even better is if you apply power part way down the strip as well.
Like this diagram I've attached from the company?
That made little sense. These companies are only interested in selling you stuff, not in doing it properly.
Also, I am assuming a thicker guage wire soldered to the adapter and strip wires would be better for amperage handling?
Use the same thickness of wire as is connected to the ends of the strips.
Apologies for the late response. It worked! Thanks very much. I connected the grounds together but the 12v's separately like you described. Appreciated how you described the consequences of my questions and the solution in detail.
