I just wanted to throw this open to anyone to see if they had any ideas as to how create a the runway 'rabbit' lights as seen by a pilot on final approach? A link to what I mean is here: White Rabbit Runway 34 in Vienna - YouTube
I'm making a runway for my son for his toy aircraft and wanted to include these prior to the threshold. The only way I can imagine doing it is by limiting power to each diode until it's its turn to brighter as part of the chasing rabbit effect. Am I correct in believing that when running power through an arduino we can only control the light by way of it being on or off (HIGH or LOW).
Any help or pointers would be greatly appreciated.
No, the Arduinos have some ports that have PWM fading.
However expect you are wanting a long string of leds, so because of the limit on the amount of power an Arduino board can directly supply you will probably need an additional chip.
A PCA9685 is designed to handle up to 16 output channels and can control them via PWM/fading.
More than 1 led on each channel possible, ie two rows of 16 leds for your landing strip and you can use more than one PCA chip if you want more lights.
The PCA9685 is perhaps not the easiest chip to program for a beginner, but some examples around and always help here.
Well, there's PWM too.
If you have, say 8 LEDs, wired up like this, this could be a simple "rabbit" code:
byte pinsArray[] = {2,3,4,5,6,7,8,9};
byte x;
void setup(){
for (x=0; x<8; x=x+1){
pinMode (pinsArray[x], OUTPUT);
digitalWrite (pinsArray[x], HIGH); // LED off
}
x=7;
}
void loop(){
x=x+1; // next LED
if (x==8){ // end of the line?
x=0; // reset to beginning
}
digitalWrite (x, LOW); // LED On
delay(1000); // adjust time as needed
digitalWrite (x, HIGH); // LED Off
delay(1000);
} // back to start of loop
Alternately, you could use individually addressable LEDs ("neopixels", WS2812B, APA102, SK6812, etc), and then you could have as many LEDs as you wanted, and make them do whatever you want.
Depending on whether your son has become an old man before his time or not, he may love using weirdo colors in the LEDs, which is possible and easy with such LEDs.
CrossRoads:
Rabbit lights are only one color tho, usually white, in my experience as an instrument rated pilot.
Right - but he's making this for his kid's toy plane. We don't know how old or mature the kid is; some would definitely jump for joy over crazy-colored LEDs.
It also might be easier to implement, since he wouldn't have to deal with the PCA9685 (in software or hardware. I don't remember if those are available in a convenient package).
Crikey guys, thanks for the multitude of replies, it's really appreciated!
My son is nearly three so I don't think he'll be contacting the CAA (FAA in the US) regarding the colour of the lights! lol I just want him to have something to play with that is safe, easy to use and most of all, fun and inspiring to him.
I'll have a read through the replies properly later and will respond in due course. Again, many thanks.
If you are just looking for the "rabbit lights", have you considered a Larson Scanner setup? I hate to take this away from the arduino world, but a couple of ic's and a few resistors/caps you can do what you want.
