//#include <SoftwareSerial.h> // import another program, a library, to communicate
//#define rxpin 0 
//#define txpin 1

//SoftwareSerial serial(rxpin,txpin);

int rxPin = 0; // this is simular to the int = setting, however this is linked to the library
int txPin = 1;
int trig = 16; 
int echo = 17; 
int trig1 = 18; 
int echo1 = 19; 
long lecture_echo; 
long cm;
int timeout = 1000;

void setup() 
{ 
  pinMode(trig, OUTPUT); 
  digitalWrite(trig, LOW); 
  pinMode(echo, INPUT);  
  
  pinMode(trig1, OUTPUT); 
  digitalWrite(trig1, LOW); 
  pinMode(echo1, INPUT); 
  
  Serial.begin(9600);   
}
void loop() 
{ 
 digitalWrite(trig, HIGH); 
 delayMicroseconds(10); 
 digitalWrite(trig, LOW); 
 lecture_echo = pulseIn(echo, HIGH,  timeout*1000); 
 cm = lecture_echo / 58; 
  
 Serial.print ("sonar 1 in cm: "); 
 Serial.println(cm); 


digitalWrite(trig1, HIGH); 
delayMicroseconds(10); 
digitalWrite(trig1, LOW); 
lecture_echo = pulseIn(echo1, HIGH, timeout*1000); //timeout in micro seconden
cm = lecture_echo / 58; 

serial.print ("sonar 2 in cm: "); 
serial.println(cm); 
  
  delay(timeout); 
}