Hi all. New to Arduino and looking forward to some really cool projects.
I've been 3D printing my current project, but i cannot continue until i figure out my wiring situation so i can alter dimensions of the base of my project to fit everything.
I'm building a "Warp Core" lamp (from star trek). If you know what i'm taking about, you know HOW the lights move along this model mocked up in the photo. I have 16ft of 12v 2835leds, single color, which i will be cutting down to 22 - 6inch strips. Each strip will have 18 leds which pull 95ma total (disregard what diagram says, tested). I want the lights to start at "1" and move towards the middle, 2 strips at a time (chase effect) 1 top and 1 bottom, until they meet in the middle. I have a 12v 6a power supply that came with them and a 2560 Mega.
I was thinking of controlling 2 strips at a time (one at either end) to make wiring easier..or just do each strip seperately.
I tried searching i am finding info on RGB strips , but nothing specifically on single color short strips.
That's 396 LEDs. Any example of a Warp Core Lamp I see just now has subtle color changes meaning
you will be animating 396 LEDs at some refresh rate
I would first calculate whether this is feasible. Again, at a glance, you should be able to achieve a decent frame rate.
Since every LED needs a new color every frame, I would recommend that you shift the complexity of managing multiple small strips from hardware (wiring) to software (clever management of subsections of certain lengths at certain offsets).
The details can be placed in functions that wood allow you to think and deal with multiple independent strips, The real LEDs can be on just one pin, and strip.show (haha, that always gets me) can be called at the frame rate in your frame loop.
I find software more fun to play with. Also, it makes testing easier, as you can start programming the animation and seeing things to change/fix/improve before you've ever cut a strip at all.
Your level of programming skill and/or desire to learn will determine which of several defensible approaches to accomplishing this kind of software abstraction. I tend to use arrays of structures, modern thinking adds notions of C++ classes, about which I know too little.
But here be people who can help, the real idea is that you only need one real strip on one real pin; everything else is numbers and maths.
As for that groovy animation, looks like some sine waves in various phase relations would make the things I've seen fairly straight ahead.
It sounds like the LEDs on your strip are not individually addressable. Isn't 2835 a package size, not a part number? Also 12V strips are usually, but not always, just plain LEDs wired in parallel. In that case, the animation would be limited to PWM modulating 22 strips. You would need independent transistor drivers or some IC driver solution for that - maybe 9 IC's that can drive 8 outputs each. Then you need 22*3=66 sources of PWM - so multiple Arduinos or some PWM modules.
It may be easier for you to use addressable LEDs such as WS2812B's.
As you don't appear to have addressable LED strips, being single color and no mention of any controller chip,
I think you need to add some smarts to the mix.
I have a board with 32 N-channel MOSFETs (AOD514 or similar) that can sink the needed current per segment (95mA) and a 2nd board that can PWM them (SX1509 based, I2C controlled). With a few boards, you can then PWM all the various segments and create the desired effect.
Here are the 2 boards pictured with an Atmega1284P based controller board. As it is I2C, a smaller 328P based board could also be used, or some other board with I2C.
would it just be better to use addressable led strips running from top to bottom of the model... then create the chase to middle effect? I thought my idea of using plain led in short strips would be easy. guess not.
Haha, trust me to make it more complicated. I am going through a smart pixel phase! It didn't occur to me that you are using dumb pixels, so to speak.
Also it seems every warp core animation is simple in that a ring is all one color. Unless you want to leave the possibility of creating other kinds of animations your hardware can be equally simple. I would still probably use smart LEDs.
I don't think there is any problem running multiple strips off one output, you could have N number of LEDs around the circumference of one band, but the N strips would be from bottom to top length 22 or whatever number of energy levels there are. They would all run the same chase to the middle.
I like the little USB charging device Warp Core that Think Geek sold. Car size about. YMMV!
Quote from: alto777 Sun Nov 15 2020 13:19:21 GMT-0800 (Pacific Standard Time)I don't think there is any problem running multiple strips off one output, you could have N number of LEDs around the circumference of one band, but the N strips would be from bottom to top length 22 or whatever number of energy levels there are. They would all run the same chase to the middle.
a7
exactly. this is all I want. no other colors or effects.. just the blue chase to middle. I wanted 22 strips wrapped around the circumference of a 1 1/2 ABS pipe running through the middle of the model. With all wires running inside the pipe.
trying to find Leds that exactly match the spacing between rings won't work. there are 20 total rings (4 clear sections) on mine. the picture has 6 sections. I'm making mine shorter.
in that picture, you can see it's just a pre-made led strip with chase. lighting multiple led at once. so they makes it look like 5 rings are lit at once as it moves up. I want this: see pic. one ring at a time... to be closer to that of the show. The gif actually skips a few frames so it looks like the light does too..but each is lit by itself.
So it looks to me that each ring has at least 3 levels, or maybe 4. Off, dim, mid-bright, and full bright.
So you could have 3 rings of LEDs at each location and turn on 1, 2 or 3.
You could have 1 ring of LEDs and PWM them to achieve the different brightnesses.
Are there other options? Probably.
TPIC6B595 can sink 150mA per output. If you have a ring that can be driven by one output, then a string of chips could drive the various rings as another option. I offer a board with 12 chips, 96 outputs. Or the 32 N-channel MOSFET board for higher currents.
As an example, here is the 32-MOSFET board fading some LEDs strips up & down. My son wrote the code for it when he was in college, so it wouldn't be too difficult to expand it to more strips
I dont need varying levels of brightness, just 1 row on, then off, next row on, then off....to the middle, then start over.
Could i just setup a board with 12 30N06LE mostfets...hook 1 strip to each, and connect each mosfet to 1 pwm pin on my Mega...connect my 12v power supply to VIN and LEDs. Then just control the on\off timing for each strip?
I'm still trying to learning, slowly, so forgive if that sounds completely wrong haha. Still trying to figure out exactly what PWM pins do.
Like this diagram? But with 12 mosfets in 12 pwm pins and Only with 1 power source
I think you need a setup like this. The LED strips you show have individual resistors per LED for current limiting, you may also have a strip with 1 resistor per 3 LEDs, which generally require 12V.
The 30N06LE N-channel MOSFET is obsolete, you can find better parts.
This would be a much better part https://www.digikey.com/en/products/detail/alpha-omega-semiconductor-inc/AOT2618L/3603378
It has a very low Rds (on resistance) with 4.5V on the gate pin, and at high currents.
If you can't find a rating like that in the datasheet, it's not really a "logic level" MOSFET.
which I normally build up with screw terminals, and drive with 74HC595 shift registers, or the shift registers can be left off an and wires can be soldered on to drive the gates, and male or female headers used to make the gate connection.
Yes. You can see 3 LEDs and one current limit resistor per segment. So for dimming, you'd use PWM.
Apply 12V to the + in a segment, or section of segments, and use PWM to drive a NPN or N-channel MOSFET to control the -. High PWM output turns on the transistor, allowing it to sink current to Gnd.
How many mAs/ring (based on how many 3-LED sections/ring) will determine the MOSFET needed.
I may have mentioned that I have a board with 32 MOSFETs. A mega has 16 PWM outputs, and you can fake more of them using software. I think you said there are 22 rings? Soo 6 software PWM wouldn't be a big deal.
jimLee:
Wouldn't it be a hole heck of a lot easier to just use neoPixles? There'd be no hardware added at all.
-jim lee
It'd be a whole lot easier to just buy a 2020 Corvette, instead of building one...but where is the FUN in that That's why i never compliment people driving expensive cars. All you did was BUY IT. If you BUILT IT...you deserve the compliment.
That's why i never compliment people driving expensive cars. All you did was BUY IT. If you BUILT IT...you deserve the compliment.