Using the Pmod DA2 with Arduino Uno

/************************************************************************
*
* Test of the Pmod 
*
*************************************************************************
* Description: Pmod_DA2
* The output voltage of the Pmod is chosen by the user from the
* Serial monitor
*
*
* Material
* 1. Arduino Uno
* 2. Pmod DA2
*
************************************************************************/

#define CS 10 // affectation of CS pin
#include <SPI.h> // Include library
char tableau[4] = {0,0,0,0};
int i = 0;
long valeur;
long consigne;
int consigne_basse;
int consigne_haute;
int val=0;
float tension;

void setup()
{
 Serial.begin(115200); // initialization of serial communication
 SPI.begin(); // initialization of SPI port
 SPI.setDataMode(SPI_MODE3); // configuration of SPI communication in mode 3
 SPI.setClockDivider(SPI_CLOCK_DIV16); // configuration of clock at 1MHz
 pinMode(CS, OUTPUT);
}

void loop()
{
 Serial.println("Enter the voltage in mV on 4 digits then Send");
 while (Serial.available()==0); // wait for data
 for(i = 0;i<4;i++) // Loop to write data in a table
  {
  tableau[i]=Serial.read();
  delay(1);
  }
 delay(100);
// recomposition du nombre tension
 valeur=1000*(tableau[0]-48)+100*(tableau[1]-48)+10*(tableau[2]-48)+(tableau[3]-48);
 consigne=4095*valeur;
 consigne=consigne/5000;
 consigne_haute=consigne>>8; // order high get 4 high bits order
 consigne_basse=consigne&0XFF; // order low get 8 low bits order
 digitalWrite(CS, LOW); // activation of the CS line
 SPI.transfer(consigne_haute); // Send order
 SPI.transfer(consigne_basse);
 delay(5);
 digitalWrite(CS, HIGH); // deactivation of CS line
 delay(100);
 Serial.print("La tension de consigne est : ");
 Serial.print(valeur);
 Serial.println(" mV");
}