Random number generation on Arduino helped by many extern sensors

randomGeneration.ino

#include "math.h"
#include "Wire.h"
#include "LCD4884.h"
#include "Adafruit_BMP085.h"
#include "TinyDHT.h"
#include "DS1302.h"
#include "Ultrasonic.h"

#define TIME 300000

#define ECHO_P 8
#define TRIG_P 9
#define DHT_P 10

#define MIC A2
#define LUM A3
#define SDA A4
#define SCL A5


Adafruit_BMP085 bmp;
ds1302_struct rtc;
DHT dht(DHT_P, DHT11);
Ultrasonic ultrasonic(TRIG_P, ECHO_P, TIME);


void setup()
{
	Serial.begin(9600);
	lcd.init();
	lcd.clear();
	lcd.turnBacklightOn(false);

	dht.begin();
	while(!bmp.begin())
	{
		Serial.println("Error with BMP085 !");
		delay(1500);
	}
}


void loop()
{
	float temp = 0, hygro = 0, pressure = 0, luminosity = 0, distance = 0;
	int seconds = 0;

	int somme = 0, n = 1;
	double ecarType = 0;

	uint32_t seed = 0;
	char seedX[10] = {0}, ecarTypeX[10] = {0};

	for( ; ; delay(100))
	{
		while(analogRead(MIC) > 400.0) //Generate a number if a big sound is detected
		{
			temp = (bmp.readTemperature() + dht.readTemperature(0)) / 2.0;
			hygro = dht.readHumidity();
			pressure = (bmp.readPressure() / 100.0);
			luminosity = (100.0 * analogRead(LUM)) / 900.0 ;
			distance = ultrasonic.Ranging(CM);

			DS1302_clock_burst_read((uint8_t *) &rtc);
			seconds = 10 * rtc.Seconds10 + rtc.Seconds;

			seed = hash(temp, hygro, pressure, luminosity, distance, seconds, n);
			ecarType = dispersion(seed, n);
			n++;

			lcd.clear();
			dtostrf(seed, 1, 0, seedX);
			dtostrf(ecarType, 1, 0, ecarTypeX);
			lcd.writeString(0, 0, "Random:", MENU_NORMAL);
			lcd.writeString(0, 2, seedX, MENU_NORMAL);
			lcd.writeString(0, 4, "Dispersion:", MENU_NORMAL);
			lcd.writeString(15, 5, ecarTypeX, MENU_NORMAL);
		}
	}
}


uint32_t hash(float temp, float hygro, float pressure, float luminosity, float distance, int seconds, int n)
{
	uint16_t faible = 0, fort = 0;

	fort = (int)abs(cos(temp*100 - hygro*100) + log((pressure*100)) + distance / luminosity*100 + seconds);
	faible = (int)abs((temp*100 + hygro*100 + 1 / pow(pressure*100, n) + sin(luminosity*100)) * exp(1 / (seconds + 1)));

	return (((uint32_t)fort << 16) | faible);
}


double dispersion(int seed, int n)
{
	static int somme = 0;
	static double nVariance = 0;

	somme += seed;
	nVariance += pow(seed - (somme / (float)n), 2);
	
	return sqrt(nVariance / (float)n);
}