Random Number

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Utility

This library allows users to get a random number.

randomSeed

Description

randomSeed() initializes the pseudo-random number generator, causing it to start at an arbitrary point in its random sequence. This sequence, while very long, and random, is always the same.

Syntax

randomSeed(unsigned int seed)

Parameters

seed: A number to generate the seed

Returns

None

random

Description

The random function generates pseudo-random numbers.

Syntax

long random(long min_num, long max_num)

Parameters

min_num: Lower bound of the random value, inclusive (optional)
max_num: Upper bound of the random value, exclusive

Returns

A random number between min and max-1 (long)

This example outputs a random number from 0 to 99 every 100ms.

        #include <Arduino.h>
        #define INTERVAL 100
         
        void setup()
        {
            Serial.begin(9600);
            randomSeed(millis());
        }
         
        void loop()
        {
            Serial.println( random(0, 100) );
            delay(INTERVAL);
        }