Randomly and independent blinking LEDs with adjustable half-life
I wrote an exponentially distributed random blinker capable of independently controlling several LEDs in parallel. Basically, the user sets up the interval of time during which the LED has a probability of 1/2 of blinking (half-life).
//An exponentially distributed blinker
byte outpins[] = {13, 12, 11}; //output pins
#define TAU 1000. //half-life in ms: interval of time
#define CYCLE 10 //sampling rate in ms
#define ON 1 //number of cycles the output stays on
#define PRECISION 32767
#define THRESHOLD PRECISION*pow(2, -CYCLE/TAU)
#define SIZE (sizeof(outpins)/sizeof(byte))
byte ttl[SIZE];
void setup(){
for(int i=0; i<SIZE; i++){
pinMode(outpins[i],OUTPUT);
}
randomSeed(analogRead(0)+analogRead(1)+analogRead(2));
}
void loop(){
for(int i=0; i<SIZE; i++){
if(random(PRECISION) > THRESHOLD){
ttl[i] = ON;
}else{
ttl[i] = max(0,ttl[i]-1);
}
}
for(int i=0; i<SIZE; i++){
if(ttl[i]>0){
digitalWrite(outpins[i],HIGH);
}else{
digitalWrite(outpins[i],LOW);
}
}
delay(CYCLE);
}
(1 vote)
