dtostrf return NANO

Projects Programming
3

This is the function:

void Estacionarias(){
//Calculo ROE
Dirroe = sqrt (Directa);
Refroe = sqrt (Reflejada);
Roe = (Dirroe+Refroe)/(Dirroe-Refroe);
lcd.SET_FontSize(2);
dtostrf(Roe, 1, 2, Roetxt);
lcd.WriteText(3,5,Roetxt,1);
delay(25);
lcd.WriteText(3,9,":1",1);
if (Roe > 2.90){
Alarma_roe();
}