aab

#include "DHT.h"
#define DHTPIN 2
#define DHTTYPE DHT11

DHT dht(DHTPIN, DHTTYPE);

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

void loop() {
  delay(500);
  int h = dht.readHumidity();
  int t = dht.readTemperature();
  char x = Serial.read();

if(x == 'a'){
    Serial.print(h);
    Serial.print(",");
    Serial.println(t);
  }
}