Hi everybody,
I just signed up to this forum, and hopful to get help and give help if I can.
Unfortunately, I need to ask help, cause I desided to make a project, that is yet above my knowledge.
I would like to controll 50m (I know it is quite long) 24V addressable RGBW LED stripes, with arduino. If it is possible, I'd like to controll it from preprogrammed buttons, and from a simple colour disk from an application via internet.
I have used arduino in school, a long time ago, and I didn't used it since. I don't have any arduini board now, so I start from skratch.
Could anyone help me with how to start, and could it be done with arduino please?
Yes, but you may need to carefully choose which model of Arduino, with enough RAM memory for such a long strip, and internet/network connectivity.
With 24V strips, usually it is not possible to address each led individually, but only to control groups of 6 LEDs.
Supplying power to the strip will be the most difficult part of the project, I suspect. I suggest your first task is to estimate the total current that the strip could consume if all LEDs were set to white at maximum brightness.
And we would like to know how many LEDs there are per meter. Then you could use a current calculation of 60 mA per LED to work out your current capacity requirements.
One step at a time. That sounds tricky. Get the strip working first.
The description says: The RGBW addressable LED COB tape light uses a DC 24 volt low voltage input, a separate circuit loop every 71.43mm, and each 71.43mm=1 pixel, so there are 14 pixels one meter and 70 pixels per roll. 5 meters in a roll, 90W/roll, choose a 150W 4.16A led power supply
If I'm correct, it means that 90W/5m, so I need 900W for the whole lenght (though that 150W suggestion would be for the full bright status??).
Also if I understand it correctly, 5m=5000mm, 1 pixel is 71.43mm, so i can use 70 addresses / 5m. Altogether 700 addresses for the 50m.
I was thinking to supply the strip at every 5m in paralell.
What I don't know, is that how should I address the 50m in 1 line, which is 5V (if I'm correct)? Can the address line be connected in paralell, at every 5 or 10m?
Also I replied Grumpy_Mike, that I don't know exactly which arduino board(s) should I buy..
In the world of LED strips 24V is not a low voltage input, in fact it is the highest I have ever seen.
What is important is the current and I hate people who hide behind the "power" specification. The two are linked together using the equations:-
W = V * I ....... where W is the watts, V is the voltage and I is the current
So rearranging this gives
I = W / V
So for 900 W, that will supply a current of
I = 900/24
Which is 37.5 Amps. That is a very hefty amount of current so you need it all to be available for the strip to work. Also you need a power supply to be able to supply more than this because you should never use a power supply at its full rated value but as a rule of thumb only run it at 80% full capacity.
Remember the Arduino works only at 5V so you will need some sort of signal boost circuit to get the data signal up to that level.
Each LED requires three bytes per LED of storage for the data. So that is 700 * 3 = 2100 bytes of memory.
This rules out an Arduino Uno as that has only 1K of memory. Your best bet is the Arduino Mega, with 8K of storage memory.
I think the best solution would be to get an ESP32(s) devkit. That also has WiFi builtin
That is actually not a very high resolution.
That is a bit over 4 universes, that should get you a refresh rate of about 40Hz which is really nice.
Actually memory wise you can probably get away with an ESP8266 nodeMCU or Wemos.
You only really need 1 output pin (maybe 2 if you want block any signal that should not be sent to the strip) You want WiFi. For ESP boards i always use the Makuna neopixelbus library since it has methods that do not interfere with WiFi at all.
If you do choose an ESP board, you should take into account that these are 3.3v devices, and therefore you will need to 'up' the logic level to 5v for the strip. That can easily be done with a TTL 7400 series chip.
Good thing about 24v Strips is that they are affected less by voltage drop. Voltage drop in absolute. If a cable (or ledstrip) drops .5v per meter, on 12v strip that means that after 5 meters only 9.5v is left, whereas on 24v strip that would be 21.5v which does not impact as much.
Good point so I did some digging about with the data sheet that is underneath the video on that site. That was not very helpful but I found that the basis of the strip was the WS2814 chip. So further digging I found the way this chip works. The data to this is shown in this PDF.
Notice the diagram on page 6. This shows that if you use 24V to drive the strip then you only get the addressable bits in blocks of 6 LEDs at a time. This means that any pattern you produce you can only have a resolution of 6. Is this enough for your intended application? At a 12V supply you have a resolution of 3 LEDs per address, is that better, or do you want single pixel resolution. If you do require single LED resolution, this is not the LED strip for you.
However, it does show the data transfer protocol which looks like you will be able to use either the AdaFruit or Fast LED libraries to drive this strip.
Yes it would, but having all that extra stuff that you do not use, means you are paying extra for features over and above what the project needs.
For example where does WIFi fit into your project?
You may be confused by this word. It is used in DMX lighting rigs and is not really relevant here, as I think you are not wanting a theater lighting rig. However, if you are interested in this, here is a link to start you off.
Don't make any assumptions here, i know exactly what it means. Though i had just overlooked that these are RGBW pixels which actually does change things a little. I work with led lighting a lot and since we are talking about 800KHz transmission here, what i am doing is some quick math to determine what the framerate comes down to. The way addressable ledstrip is mostly controlled these days is through Art-Net nodes and those are usually limited to 4 Universes per output, since that results in a framerate similar to DMX512 (which is 250KHz + Start an 2 stop bits, so 11 bits per byte)
So you are correct in say that it is not applicable, but i am just using it as a calculation unit, and as such it is. Then i did make a mistake though, which unfortunately, you did not catch, but at least a saw it in the re-hash.
So again. at RGBW, that is 128 pixels per universe, so we are looking at 700 / 128 which is about 5.5 Universes, that should result in a Frame-rate better than 30Hz (6 Universes does)
It is a very rough calculation but more to establish if there will be a need to create multiple inputs on the Led-object or whether just a single chain will suffice, which i think in this case it will.
I single chain is simpler in both physical layout as well as programming.
The OP wants to control the Leds remote (even over the internet) for that a router connection somewhere is required isn't it ?
As far as i know FastLED doesn't support RGBW, there have been people coming with questions about that on the forum. Adapting the code to do so is not impossible, but it doesn't have it straight out of the box.
I think the adafruit does support RGBW but i am not sure, i haven't used that library recently.
The data protocol used for single data-wire ledstrip has started to converge. There is no standard, but WorldSemi uses the same timing for (almost) all it's chips (WS2821 uses DMX and a 3x speed version of DMX) and most other manufacturers use a timing which is so similar that usually there are no compatibility issues. The thing that varies most is the break-time, but if it is set at 300us,(WS2812b) almost all chips will reset to accept data again.
Mainly you don't need all the pins, and so a more compact board is what i am suggesting.
An ESP of some kind, and in my advice i want to include that first rough Frame-rate calculation.
The library i provided a link to, uses the I2S protocol on an ESP (by default) and that runs fully in the Background. I2S is meant for audio sampling and uses DMA (Direct Memory Access) . Interrupts can stay enabled and timing is constant, nothing interferes with it anymore. There is significant memory overhead since a single bit is represented in memory by 4 bits (or more recently 3 bits) in the output buffer, but on an ESP memory is quite big. On an ESP8266 there is only 1 output pin available, and therefore only a single chain can be controlled. But on an ESP32 there is already 2 I2S busses and the library supports a parallel mode where you can have 8 outputs per bus. (or even 16, but i can't really imagine that purpose for that)
So depending on the expected framerate, i would suggest an ESP8266 of some kind will suffice, and even an ESP-01 will do, though that board does not come with a 3.3v regulator on board and there is something to be said for getting a board that does have. Just like the MKR WiFi these are 3.3v MCU's (so logic level shifting to 5v is required) and not nearly as expensive. The ESP32 also comes with Bluetooth, but i am not sure that is required for this project.
Did you actually look at that data sheet and see the signal format? It is exactly the same as as the standard WS2812 format.
In which case I don't know what you mean, let alone the OP.
Again did you read the data sheet, that is not how these devices work.
I would not advise anyone to use a ESP chip apart from the official Arduino ESP32.
These are complex devices, and full of variants, making them even harder for a beginner to understand. Over half the posts we get these days are from people failing to get some dirt cheap, poorly constructed, clone of this sort of chip to work.
Other than that they use 4 bytes per pixel rather than 3 bytes per pixel.
By now at least most 3rd party libraries have caught up mostly with the silly design Arduino designers came up with, but initially that was not the case and i don't know if that applies to any library i recommend. For LED-strip, an ESP32 is great and most devkits as well as a barebones chip will work.
This is all clearly over your head. I am trying to explain how long a frame takes to transmit, and the math is fairly straight forward. I am noting an exception on the most common protocol.
Do you guys know each other? (Grumpy_Mike and Deva_Rishi)
Thanks for the infos. Though now I'm a bit confused, what should I buy:)
I checked out the ESP boards, and I maybe this one would be sufficient for my project:
wow,