Good morning everyone. I'm brand new to the forum and brand new to Arduino. I'm trying to upload a code I located for an LED fireworks pattern and keep getting an error. I'm using an Uno board and a WS2812b LED strip. My problem is that I get an error when I attempt to upload the code to my board. Below is the start of the code along with the error I'm receiving.. I'm only just starting to learn how to code and need help debugging this. Thanks in advance for any help!
Here's the error:
Arduino: 1.8.19 (Mac OS X), Board: "Arduino Uno"
sketch_apr24d:6:1: error: expected unqualified-id before 'public'
public class FireworksEffect : LEDEffect
^~~~~~
exit status 1
expected unqualified-id before 'public'
Here's the beginning of the code:
//
// FireworksEffect - Free for all use from Davepl
//
// Fireworks Effect for Fourth of July
public class FireworksEffect : LEDEffect
{
// Each particle in the particle system remembers its color,
// birth time, postion, velocity, etc. If you are not using DateTime,
// all you need in its place is a fractional number of seconds elapsed, which is
// all I use it for. So timer()/1000.0 or whatever should suffice as well.
public class Particle
{
public CRGB _starColor;
public DateTime _birthTime;
public DateTime _lastUpdate;
public double _velocity;
public double _position;
public static Random _rand = new Random();
public Particle(CRGB starColor, double pos, double maxSpeed)
{
_position = pos;
_velocity = _rand.NextDouble() * maxSpeed * 2 - maxSpeed;
_starColor = starColor;
_birthTime = DateTime.UtcNow;
_lastUpdate = DateTime.UtcNow;
}
//
// FireworksEffect - Free for all use from Davepl
//
// Fireworks Effect for Fourth of July
public class FireworksEffect : LEDEffect
{
// Each particle in the particle system remembers its color,
// birth time, postion, velocity, etc. If you are not using DateTime,
// all you need in its place is a fractional number of seconds elapsed, which is
// all I use it for. So timer()/1000.0 or whatever should suffice as well.
public class Particle
{
public CRGB _starColor;
public DateTime _birthTime;
public DateTime _lastUpdate;
public double _velocity;
public double _position;
public static Random _rand = new Random();
public Particle(CRGB starColor, double pos, double maxSpeed)
{
_position = pos;
_velocity = _rand.NextDouble() * maxSpeed * 2 - maxSpeed;
_starColor = starColor;
_birthTime = DateTime.UtcNow;
_lastUpdate = DateTime.UtcNow;
}
Actually here is all the code. I accidentally repasted the short part:
//
// FireworksEffect - Free for all use from Davepl
//
// Fireworks Effect for Fourth of July
public class FireworksEffect : LEDEffect
{
// Each particle in the particle system remembers its color,
// birth time, postion, velocity, etc. If you are not using DateTime,
// all you need in its place is a fractional number of seconds elapsed, which is
// all I use it for. So timer()/1000.0 or whatever should suffice as well.
public class Particle
{
public CRGB _starColor;
public DateTime _birthTime;
public DateTime _lastUpdate;
public double _velocity;
public double _position;
public static Random _rand = new Random();
public Particle(CRGB starColor, double pos, double maxSpeed)
{
_position = pos;
_velocity = _rand.NextDouble() * maxSpeed * 2 - maxSpeed;
_starColor = starColor;
_birthTime = DateTime.UtcNow;
_lastUpdate = DateTime.UtcNow;
}
public double Age
{
get
{
return (DateTime.UtcNow - _birthTime).TotalSeconds;
}
}
// As the particle ages we actively fade its color and slow its speed
public void Update()
{
double deltaTime = (DateTime.UtcNow - _lastUpdate).TotalSeconds;
_position += _velocity * deltaTime;
_lastUpdate = DateTime.UtcNow;
_velocity -= (2 * _velocity * deltaTime);
_starColor = _starColor.fadeToBlackBy((float)_rand.NextDouble() * 0.1f);
}
}
// A Palette256 is just a way of picking a random color from the rainbow.
// If you can provide a random color, you're set... this is just the
// easiest mechanism I had handy.
protected Palette256 _Palette = new Palette256(Palette256.Rainbow);
protected bool Blend = true;
protected double MaxSpeed = 375.0f; // Max velocity
protected double NewParticleProbability = 0.01f; // Odds of new particle
protected double ParticlePreignitonTime = 0.0f; // How long to "wink"
protected double ParticleIgnition = 0.2f; // How long to "flash"
protected double ParticleHoldTime = 0.00f; // Main lifecycle time
protected double ParticleFadeTime = 2.0f; // Fade out time
protected double ParticleSize = 0.00f; // Size of the particle
protected Queue<Particle> _Particles = new Queue<Particle>(); // FIFO particles
private static Random _random = new Random();
// All drawing is done in Render, which produces one
// frame by calling the draw methods on the supplied
// graphics interface. As long as you support "Draw
// a pixel" you should be able to make it work with
// whatever mechanism to plot pixels that you're using...
protected override void Render(ILEDGraphics graphics)
{
// Randomly create some new stars this frame; the number we create is tied
// to the size of the display so that the display size can change and
// the "effect density" will stay the same
for (int iPass = 0; iPass < graphics.DotCount / 50; iPass++)
{
if (_random.NextDouble() < NewParticleProbability)
{
// Pick a random color and location.
// If you don't have FastLED palettes, all you need to do
// here is generate a random color.
uint iStartPos = (uint)(_random.NextDouble() * graphics.DotCount);
CRGB color =
_Palette.ColorFromPalette((byte)_random.Next(0, 255), 1.0f, false);
int c = _random.Next(10, 50);
double multiplier = _random.NextDouble() * 3;
for (int i = 1; i < c; i++)
{
Particle particle = new Particle(color, iStartPos, MaxSpeed *
_random.NextDouble() * multiplier);
_Particles.Enqueue(particle);
}
}
}
// In the degenerate case of particles not aging out for some reason,
// we need to set a pseudo-realistic upper bound, and the very number of
// possible pixels seems like a reasonable one
while (_Particles.Count > graphics.DotCount)
_Particles.Dequeue();
// Start out with an empty canvas
graphics.FillSolid(CRGB.Black);
foreach (Particle star in _Particles)
{
star.Update();
CRGB c = new CRGB(star._starColor);
// If the star is brand new, it flashes white briefly.
// Otherwise it just fades over time.
double fade = 0.0f;
if (star.Age > ParticlePreignitonTime && star.Age <
ParticleIgnition + ParticlePreignitonTime)
{
c = CRGB.White;
}
else
{
// Figure out how much to fade and shrink the star based on
// its age relative to its lifetime
double age = star.Age;
if (age < ParticlePreignitonTime)
fade = 1.0 - (age / ParticlePreignitonTime);
else
{
age -= ParticlePreignitonTime;
if (age < ParticleHoldTime + ParticleIgnition)
fade = 0.0f; // Just born
else if (age > ParticleHoldTime + ParticleIgnition + ParticleFadeTime)
fade = 1.0f; // Black hole, all faded out
else
{
age -= (ParticleHoldTime + ParticleIgnition);
fade = (age / ParticleFadeTime); // Fading star
}
}
c = c.fadeToBlackBy((float)fade);
}
ParticleSize = (1 - fade) * 5;
// Because I support antialiasing and partial pixels, this takes a
// non-integer number of pixels to draw. But if you just made it
// plot 'ParticleSize' pixels in int form, you'd be 99% of the way there
graphics.DrawPixels(star._position, (uint)ParticleSize, c);
}
// Remove any particles who have completed their lifespan
while (_Particles.Count > 0 && _Particles.Peek().Age >
ParticleHoldTime + ParticleIgnition + ParticleFadeTime)
{
_Particles.Dequeue();
}
}
I take it all back... The code you posted, as noted above, is incomplete. The BRACES should have ooen-braces matching close-braces. "We" think you pasted part of a sketch (library) from an online article. Look back at that article or video and share the link. It will help you, immensely.
His YouTube display is very impressive. I really want to attempt to get my LED strip to do this. It just has a error when uploading to my Uno right at the very beginning. Hopefully someone here can see what the error is.
What you have posted and linked, thanks, is not a complete sketch at all, it is just a very fancy object or component that is designed to be used in a larger context.
It isn't clear to me that that context is meant to include the typical Arduino sketch.
I am not saying this is unusable, just that to do would require more knowledge and skill than you possess at this time.
It might be very easy to work up a sketch that uses this object.
If no one just does it here, you'll have to start where we all did and learn enough about how sketches are constructed and how externally sourced gems like this can be incorporated.
Or have you already tried? In which case again, post your entire effort with this, not just the part you've done above.
Dave'a Garage says: "Written in C# with proprietary blah blah, using ESP blah blah... WLED tried to duplicate it but blah blah..."
I call these "Etsy projects" which show you the beautiful results, but none of the underlying preperation. The is a career-ful of work this guy did. He's probably an FPGA firmware programmer, and those folks are real geniuses. Good luck. Never give up.
Sounds like I best dig in and learn enough to figure out a way to simulate this myself. I'm a rookie at best with Arduino and creating sketches, but I also like a challenge. Seems maybe I should start from scratch - I have the goal. Learning is fun!
Start with the examples in the IDE. If you are def headed towards something with LED strips, just keep googling for Arduino projects that use them, or tutorials that feature them, and read read read the code presented as if you knew what it was all about.
It's all hard until it is easy. Good thing there are tons of ppl using Arduino and neopixels, or "smart LEDs".
