I just finished my first Arduino Uno project, where I have an Analog RGB LED strip and I control it to change colors.
Along the way, I got into a little hassle with connecting the wires to the Arduino And I still have to use Mosfets and resisters as well.
I was wondering if there's anything out there that makes the connection between the strip and the Arduino simple.
Please help me with that since I want to produce in bigger quantity.
FET is not required for WS2812. Only 1 resistor on the communication line (I tried without it and the strip still works). With WS2812, more complex effects can be made because each diode is programmed independently. The disadvantage is the higher price of the tape.
There was never any doubt about it working without the protective resistor. The concern is that it might at some point be damaged if the LED strip is unpowered but the Arduino is driving the data line, or if a long transmission line between Arduino and LED strip produces transients beyond the input voltage limits of the strip.
And such events may cause progressive degradation rather than prompt failure.
An Arduino I/O pin can only directly power one or two LEDs. With additional circuitry (and an additional-external power source) you could control all of the lights in your house!
A "regular" LED strip where all of the LEDs of the same color are connected-controlled together ALWAYS requires a MOSFET driver circuit (or transistor or relay, etc.) for each color. A MOSFET or transistor will "pass" PWM so you an also dim the LED strip.
Addressable LED strips (NeoPixels, etc., where every LED can be individually addressed/controlled) have a built-in driver chip for each LED so you only have to supply power and low-power control signal. Again, you dim the LEDs, but this time with control commands/signals rather than with PWM from the Arduino.
As I understand the NeoPixels are not allowed to be connected to power and to PC at once. Is this accurate?
I will have this controlled from a program so I need it should be connected to the PC as well.
You are likely confusing that with a design limitation of the UNO and Mega boards (not shared with the Nano).
You should not power the UNO with 5 V via the "5V" pin while it is connected to a PC. There is some possible risk of 5 V being fed back into the PC's USB system and causing it to malfunction or be damaged.
With regard to the NeoPixel/ WS28212, Powering the LEDs without the PC or other controller is perfectly safe. The resistor is there to protect the first LED from being driven with 5 V data while it is not powered.
Please explain what aspect of the setup you want to be simplified. Is it the physical connections, so do you want to replace hand-soldered connections with some kind of off-the-shelf connector? Or do you have problems with the driving circuitry that includes the mosfet and some other components?
Have you considered laying out a simple PCB for the drivers? You mention 'bigger quanitities' (how many are we talking?), which implies that a PCB may be worthwhile and also that the really minor inconvenience of having a few mosfets around doesn't have to be a drawback. You may also find that discrete led strips driven with mosfets is likely much cheaper than replacing the leds with ws2812 strips. Especially in a volume production environment this would in fact be a concern.
Long story short: can you clarify your requirements and restrictions a bit more? Because we can start giving all kinds of advice, but at present I'm not really sure what direction we should be taking this in.
Thanks for your response. I'll try to explain a bit more.
I'm working on a project to get a LED Status light controlled by Arduino, this will be controlled by sending commands to the Serial port from an outside program and have Arduino change colors accordingly.
A built a sample of that which works fine, however, having this for mass production is quite difficult (I'm talking of about 100 units to begin) since the wiring makes it very messy.
The prototype I built had 3 MosModule connected on the Arduino board Case and the wiring was one big tangle. I can't go ahead like this with mass production.
I'd make a pcb for this and forego the arduino hardware and other off the shelf modules.
You speak of a status light; does that mean a single 3-color element would do, or does it have to be a strip? In case of the latter, what are the shape & size requirements? Is it something you could implement in the PCB as well?
I want it on the top of a pole for a status light to be seen from far so I would have the Arduino etc. under the counter somewhere and have the strip connected to a long wire up on the pole. The strip is just the easiest way that I can see to have it done. I put it in a nice diffuser and it looks very cool.
So make a small pcb with a connector for a led strip. Would have been easier to integrate the leds into the pcb but that may not fit inside the pole you speak of. How much space would you have at the tip of the pole?
After searching and searching I found this: RGB LED Strip Driver Shield v1.0-DFRobot
This was exactly what I was looking for. it has the Mosfets on the PCB and it comes out with 4 pins that connect LED wires tight!