Mysensort mit DHT12 (i2C)

[michlb1982]

Hello

Does anyone built up an Mysenors Humidity Node with an DHT12 it is an I2C sensor...

but I2C is needet for the NRF24+ or?

Thanks

[mfalkvidd]

@michlb1982 the nrf radio uses SPI, not I2C.

I haven't seen anyone using the dht12, but there are examples that use other i2c sensors.
https://www.mysensors.org/build/pressure
https://www.mysensors.org/build/light-bh1750
https://www.mysensors.org/build/rfid

[michlb1982]

Well i did it... i've got a working MYSENSOR with DHT12...
here the Code ... its not nice but it works...

// Enable debug prints
#define MY_DEBUG

// Define Node ID
#define MY_NODE_ID 128
//#define MY_REPEATER_FEATURE


// Enable and select radio type attached 
#define MY_RADIO_NRF24

#include <SPI.h>
#include <MySensors.h>  
#include <DHT12.h>
#include <Wire.h>
DHT12 dht12;

#define SENSOR_TEMP_OFFSET 0

// Sleep time between sensor updates (in milliseconds)
// Must be >1000ms for DHT22 and >2000ms for DHT11
static const uint64_t UPDATE_INTERVAL = 30000;

static const uint8_t FORCE_UPDATE_N_READS = 10;

#define CHILD_ID_HUM 0
#define CHILD_ID_TEMP 1

float lastTemp;
float lastHum;
uint8_t nNoUpdatesTemp;
uint8_t nNoUpdatesHum;
bool metric = true;

MyMessage msgHum(CHILD_ID_HUM, V_HUM);
MyMessage msgTemp(CHILD_ID_TEMP, V_TEMP);



void presentation()  
{ 
  // Send the sketch version information to the gateway
  sendSketchInfo("DHT12", "1.1");

  // Register all sensors to gw (they will be created as child devices)
  present(CHILD_ID_HUM, S_HUM);
  present(CHILD_ID_TEMP, S_TEMP);

  //metric = getControllerConfig().isMetric;
}


void setup()
{
  Wire.begin();
}


void loop()      
{  
  // Force reading sensor, so it works also after sleep()
  //dht12.readSensor(true);

  // Get temperature from DHT library
  float temperature = dht12.readTemperature();
  if (isnan(temperature)) {
    Serial.println("Failed reading temperature from DHT!");
  } else if (temperature != lastTemp || nNoUpdatesTemp == FORCE_UPDATE_N_READS) {
    // Only send temperature if it changed since the last measurement or if we didn't send an update for n times
    lastTemp = temperature;

    // apply the offset before converting to something different than Celsius degrees
    temperature += SENSOR_TEMP_OFFSET;

    if (!metric) {
      temperature = dht12.readTemperature();
    }
    // Reset no updates counter
    nNoUpdatesTemp = 0;
    send(msgTemp.set(temperature, 1));

    #ifdef MY_DEBUG
    Serial.print("T: ");
    Serial.println(temperature);
    #endif
  } else {
    // Increase no update counter if the temperature stayed the same
    nNoUpdatesTemp++;
  }

  // Get humidity from DHT library
  float humidity = dht12.readHumidity();
  if (isnan(humidity)) {
    Serial.println("Failed reading humidity from DHT");
  } else if (humidity != lastHum || nNoUpdatesHum == FORCE_UPDATE_N_READS) {
    // Only send humidity if it changed since the last measurement or if we didn't send an update for n times
    lastHum = humidity;
    // Reset no updates counter
    nNoUpdatesHum = 0;
    send(msgHum.set(humidity, 1));

    #ifdef MY_DEBUG
    Serial.print("H: ");
    Serial.println(humidity);
    #endif
  } else {
    // Increase no update counter if the humidity stayed the same
    nNoUpdatesHum++;
  }

  // Sleep for a while to save energy
  sleep(UPDATE_INTERVAL); 
  //wait(UPDATE_INTERVAL); //for repeaters
}

i Used this library: https://github.com/Bobadas/DHT12_library_Arduino/blob/master/README.md

here the datasheet of the dht12: http://www.robototehnika.ru/file/DHT12.pdf