Mysensors 2.3.1
Domoticz 4.11506
Tested on Arduino nano and NodeMcu (same results)

#define MY_RADIO_RF24
#define MY_RF24_PA_LEVEL (RF24_PA_MIN)
#define MY_NODE_ID 114

//taken from the original and mysensors forum
//http://forum.mysensors.org/topic/1393/2-or-more-dht11-sensors-on-one-arduino-nano-mysensor/8
//http://forum.mysensors.org/topic/1462/getting-node-id-0-after-erasing-eeprom


#include <SPI.h>
#include <MySensors.h>  
#include <DHT.h>           //dht22 


//Definition of sensor
#define CHILD_ID1_HUM 1
#define CHILD_ID1_TEMP 3
#define CHILD_ID2_HUM 2
#define CHILD_ID2_TEMP 4

const int HUMIDITY_SENSOR1_DIGITAL_PIN = D0;
const int HUMIDITY_SENSOR2_DIGITAL_PIN = D1;

unsigned long SLEEP_TIME = 30000; // Sleep time between reads (in milliseconds)

//MySensor;
DHT dht1;
DHT dht2;
float lastTemp1;
float lastHum1;
float lastTemp2;
float lastHum2;

boolean metric = true; 
MyMessage msgHum1(CHILD_ID1_HUM, V_HUM);
MyMessage msgTemp1(CHILD_ID1_TEMP, V_TEMP);
MyMessage msgHum2(CHILD_ID2_HUM, V_HUM);
MyMessage msgTemp2(CHILD_ID2_TEMP, V_TEMP);

void setup()  
{ 
  
 // begin();
  dht1.setup(HUMIDITY_SENSOR1_DIGITAL_PIN); 
  dht2.setup(HUMIDITY_SENSOR2_DIGITAL_PIN);

  // Send the Sketch Version Information to the Gateway
  sendSketchInfo("2DHT22_ESP8266", "V2");

  // Register all sensors to gw (they will be created as child devices)
  present(CHILD_ID1_HUM, S_HUM);
  present(CHILD_ID1_TEMP, S_TEMP);
  present(CHILD_ID2_HUM, S_HUM);
  present(CHILD_ID2_TEMP, S_TEMP);


 // metric = getConfig().isMetric;
    
}

void loop()      
  {
    
//DHT 11 Sensor 1

  delay(dht1.getMinimumSamplingPeriod());

  float temperature1 = dht1.getTemperature();
  if (isnan(temperature1)) {
    Serial.println("Failed reading temperature from DHT 1");
  } else if (temperature1 != lastTemp1) {
    lastTemp1 = temperature1;
    if (!metric) {
    temperature1 = dht1.toFahrenheit(temperature1);
    }
    send(msgTemp1.set(temperature1, 1));
    Serial.print("T1: ");
    Serial.println(temperature1);
  
  }
  float humidity1 = dht1.getHumidity();
  if (isnan(humidity1)) {
    Serial.println("Failed reading humidity from DHT 1");
  } else if (humidity1 != lastHum1) {
    lastHum1 = humidity1;
    send(msgHum1.set(humidity1, 1));
    Serial.print("H1: ");
    Serial.println(humidity1);

  }

delay(500);

// DHT11 Sensor 2
{
  delay(dht2.getMinimumSamplingPeriod());

  float temperature2 = dht2.getTemperature();
  if (isnan(temperature2)) {
    Serial.println("Failed reading temperature from DHT 2");
  } else if (temperature2 != lastTemp2) {
    lastTemp2 = temperature2;
    if (!metric) {
    temperature2 = dht2.toFahrenheit(temperature2);
    }
    send(msgTemp2.set(temperature2, 1));
    Serial.print("T2: ");
    Serial.println(temperature2);

  }
  float humidity2 = dht2.getHumidity();
  if (isnan(humidity2)) {
    Serial.println("Failed reading humidity from DHT 2");
  } else if (humidity2 != lastHum2) {
    lastHum2 = humidity2;
    send(msgHum2.set(humidity2, 1));
    Serial.print("H2: ");
    Serial.println(humidity2);

    }
  
   
  sleep(SLEEP_TIME); //sleep a bit

  delay (2000);
}
}