Random Number generation between range

General
6

I created a full example if anyone needs something like this:

#include "application.h"

// Uncomment for faster debugging!
//#include "spark_disable_wlan.h"

int random(int maxVal);
int random(int minVal, int maxVal);

// returns a random integar between 0 and maxVal
int random(int maxVal)
{
  return random( 0, maxVal);
}

// returns a random integar between minVal and maxVal
int random(int minVal, int maxVal)
{
  // int rand(void); included by default from newlib
  return rand() % (maxVal-minVal+1) + minVal;
}

void setup(void) {
  Serial.begin(115200); // Make sure your serial terminal is closed before power the Core.
  while(!Serial.available()) { // Open serial terminal and Press ENTER.
    #ifdef SPARK_WLAN_SETUP
      SPARK_WLAN_Loop(); 
    #endif
  }

  // Waiting for a human to start the program at a random time...
  // humans are so very random :P
  uint32_t seed = millis(); 
  srand(seed); // void srand(unsigned int seed);
}

void loop() {
  // Generate a random number, from 1 - 10.
  int random_num = random(1,10);

  // Generate a random number, from 0 - 10.
  //int random_num = random(10);

  char bar[10] = "";
  int random_copy = random_num;
  while(random_copy > 0) {
    strcat(bar,"="); // Create a bargraph
    random_copy--;
  }

  // Scroll our bargraph in the serial terminal
  Serial.print(bar);
  Serial.print(" ");
  Serial.println( random_num ); 
  delay(100);
}
2 Likes