float pressure;   
float temperature;  
float altimeter;

unsigned long rpm =4900;
char text[4]="hej";

// för tidtagning
unsigned long a,b;

//char charRead;
char dataStr[100] = "";
char buffer[10];

void setup(){
  Serial.begin(9600);
 
}

void loop(void){
 dataStr[0] = 0; //clean out string
pressure = 1024.23;  //and convert Pa to hPa
temperature = 19.34;
altimeter = -3.23; //QNH is local sea level pressure
 //----------------------- using c-type ---------------------------
 //convert floats to string and assemble c-type char string for writing:
 a=micros();
 ltoa( millis(),buffer,10); //convert long to charStr
 strcat(dataStr, buffer); //add it to the end
 strcat( dataStr, ", "); //append the delimiter
 
 
 //dtostrf(floatVal, minimum width, precision, character array);
 dtostrf(pressure, 5, 2, buffer);  //5 is minimum width, 1 is precision; float value is copied onto buff
 strcat( dataStr, buffer); //append the converted float
 strcat( dataStr, ", "); //append the delimiter

 dtostrf(temperature, 5, 1, buffer);  //5 is minimum width, 1 is precision; float value is copied onto buff
 strcat( dataStr, buffer); //append the converted float
 strcat( dataStr, ", "); //append the delimiter

 strcat(dataStr, text);
 strcat(dataStr, ", ");

 dtostrf(altimeter, 5, 2, buffer);  //5 is minimum width, 1 is precision; float value is copied onto buff
 strcat( dataStr, buffer); //append the converted float
 strcat( dataStr, "\0"); //terminate correctly 
 b=micros()-a;
 Serial.println(dataStr);
 
 Serial.println(b);
 delay(1000);  
}