CODEWITHSUNDEEP
c++arraysrandomarduino
Raphael Buitendag
Raphael Buitendag

Reputation: 1

Generate random numbers from given random array values Arduino program C++

I am trying to generate random output for the leds from the given values in the array I created but it does not work, I found this online and they said do it like below but it doesn't do anything. The programme should get a random value from the array.

int randomArray[4] = { 0,85,170,255 };




void setup() {

    Serial.begin(9600);
    pinMode(red, OUTPUT);
    pinMode(green, OUTPUT);
    pinMode(blue, OUTPUT);
    pinMode(RLed, OUTPUT);
    pinMode(YLed, OUTPUT);
    pinMode(GLed, OUTPUT);
    randomSeed(millis());

}

void loop() {

    redvalue = randomArray[random(0,3)];
    bluevalue = randomArray[random(0, 3)];
    greenvalue = randomArray[random(0, 3)];
    Serial.println(redvalue);
    Serial.println(bluevalue);
    Serial.println(greenvalue);
    analogWrite(red, redvalue);
    analogWrite(blue, bluevalue);
    analogWrite(green , greenvalue);
    analogWrite(RLed, redvalue);
    analogWrite(YLed, bluevalue);
    analogWrite(GLed, greenvalue);
    delay(1000);
}

Upvotes: 0

Views: 1895

Answers (1)

Piglet
Piglet

Reputation: 28984

If you want a random element of your array you have to use a random index.

I you have 4 values in your array the index must be in the interval [0-3].

From the Arduino Reference:

random(max)

random(min, max)

Parameters min: lower bound of the random value, inclusive (optional). max: upper bound of the random value, exclusive.

Returns A random number between min and max-1. Data type: long.

int randomArray[4] = {0, 85, 170, 255};
int randIndex = (int)random(0, 4);
int randElem = randomArray[randIndex];

should do the trick, but my C++ is a bit rusty. you can probably omit the int cast.

Upvotes: 2

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