How to generate random number in your Arduino Program?

In this course we will see how to generate a random number in your Arduino Program by using the random function:

``random(min,max)``

The random function has two parameter : a minimum and maximum number. The function will generate a number between this range.

Here is an example:

``````void setup() {
Serial.begin(9600); //We initalize the serial monitor On initalise le moniteur série
int random_number=random(1,100); //We generate a random number between 1 and 100
Serial.println(random_number); // We display the random number
}

void loop() {
}``````

In our example, the number chosen can’t be equal to the maximum number you gave, in our case 100. The maximum random number chosen can be max-1 which mean 99 in our case.

As you may know, it is not as easy to have a real random number in programming language. That’s why in Arduino there a function called randomSeed which permits to change the way that’s a random number is generate.

• randomSeed()

The Randomseed function is used to create a new group of random numbers from a stable number. This number can be from an Analog input of the arduino card or a number that you choose by yourself. We will see now an example of it:

``````void setup() {
Serial.begin(9600); //We initialize the serial monitor
randomSeed(1);//We initialize the new group with the number 1
int random_number = random(0,50); //We generate our random number
Serial.println(raldom_number); // We display the number
}

void loop() {
}``````

By changing the number in random Seed, we have a new group of number and we have new random number.