BME280 temp/humidity/pressure sensor

[yoshida]

@emc2 or anybody:

Does anyone have a working BME280 mysensors arduino sketch? The code above states include mysensor.h now it is mysensorS.h, so I have renamed, but it won't compile, it says:

In function 'void setup()':

bme280:252: error: 'getConfig' was not declared in this scope

I have a MySensors Gateway USB
Version: 2.1.1 (arduino nano) with Domoticz, and I would like to use the bme280 for a battery powered outdoor temp/humidity/barometer (as DHT22 does not like battery level below 3.3V, and I would run on 2x1.5V AA)

Thanks

[emc2]

Was modified in 2.1.1, you need to change

metric = getConfig().isMetric;

to

metric = getControllerConfig().isMetric;  // was getConfig().isMetric; before MySensors v2.1.1

[anno]

Still a lot of errors in this sketch, did take some out but this is still in it:

In file included from C:\Users\x\Documents\Arduino\BME280_sensor\BME280_sensor.ino:48:0:

C:\Users\x\Documents\Arduino\libraries\BME280/BME280_MOD-1022.h:41:21: warning: extra tokens at end of #ifndef directive

#ifndef __BME280_MOD-1022_H

                 ^

C:\Users\x\Documents\Arduino\libraries\BME280/BME280_MOD-1022.h:42:21: warning: ISO C99 requires whitespace after the macro name

#define __BME280_MOD-1022_H

                 ^

In file included from C:\Users\x\Documents\Arduino\libraries\BME280\BME280_MOD-1022.cpp:40:0:

C:\Users\x\Documents\Arduino\libraries\BME280\BME280_MOD-1022.h:41:21: warning: extra tokens at end of #ifndef directive

#ifndef __BME280_MOD-1022_H

                 ^

C:\Users\x\Documents\Arduino\libraries\BME280\BME280_MOD-1022.h:42:21: warning: ISO C99 requires whitespace after the macro name

#define __BME280_MOD-1022_H

                 ^

C:\Users\x\Documents\Arduino\libraries\BME280\BME280_MOD-1022.cpp: In member function 'BME280Class::readCompensationParams()':

C:\Users\x\Documents\Arduino\libraries\BME280\BME280_MOD-1022.cpp:276:45: warning: iteration 20 invokes undefined behavior [-Waggressive-loop-optimizations]

compParams.compArray[count] = Wire.read();

                                         ^

C:\Users\x\Documents\Arduino\libraries\BME280\BME280_MOD-1022.cpp:275:3: note: containing loop

for (count = 0; count < 28; count++) { // first 28 bytes we can process like this

^

C:\Users\x\Documents\Arduino\BME280_sensor\BME280_sensor.ino: In function 'loop':

C:\Users\x\Documents\Arduino\libraries\BME280\BME280_MOD-1022.cpp:276:45: warning: iteration 20 invokes undefined behavior [-Waggressive-loop-optimizations]

compParams.compArray[count] = Wire.read();

                                         ^

C:\Users\x\Documents\Arduino\libraries\BME280\BME280_MOD-1022.cpp:275:3: note: containing loop

for (count = 0; count < 28; count++) { // first 28 bytes we can process like this

[yoshida]

@emc2 Thanks! With this modification the sketch compiled successfully. Today I had time, so put everything together, and the BME280 works with the 2.4GH radio, temp/hum/pressure all reporting like they should.

Using arduino pro mini, bme280, nrf24, 2XAA Batteries. It reports to the mysensors serial gw, and then shown in domoticz.

[Zbigniew Ko]

@yoshida Hello
You can share your sketch.
Please
I can not make modifications.
I still have a lot of errors.

[anno]

This post is deleted!

[yoshida]

Zbigniew Ko:

(2.1.1 mysensors compatible, but first you need to install the BME280_MOD-1022.h library in arduino IDE)

/**
 * The MySensors Arduino library handles the wireless radio link and protocol
 * between your home built sensors/actuators and HA controller of choice.
 * The sensors forms a self healing radio network with optional repeaters. Each
 * repeater and gateway builds a routing tables in EEPROM which keeps track of the
 * network topology allowing messages to be routed to nodes.
 *
 * Created by Henrik Ekblad <henrik.ekblad@mysensors.org>
 * Copyright (C) 2013-2015 Sensnology AB
 * Full contributor list: https://github.com/mysensors/Arduino/graphs/contributors
 *
 * Documentation: http://www.mysensors.org
 * Support Forum: http://forum.mysensors.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 *******************************
 *
 * REVISION HISTORY
 * Version 1.0 - Henrik Ekblad
 * 
 * DESCRIPTION
 * Pressure sensor example using BMP085 module  
 * http://www.mysensors.org/build/pressure
 *
 */

// Enable debug prints to serial monitor
#define MY_DEBUG 

// Enable and select radio type attached
#define MY_RADIO_NRF24
//#define MY_RADIO_RFM69

#include <SPI.h>
#include <MySensors.h>  
#include <Wire.h>

// BME280 libraries and variables
// Bosch BME280 Embedded Adventures MOD-1022 weather multi-sensor Arduino code
// Written originally by Embedded Adventures
// https://github.com/embeddedadventures/BME280
#include <BME280_MOD-1022.h>

#define BARO_CHILD 0
#define TEMP_CHILD 1
#define HUM_CHILD 2

const float ALTITUDE = 184; // <-- adapt this value to your location's altitude (in m). Use your smartphone GPS to get an accurate value!

// Sleep time between reads (in ms). Do not change this value as the forecast algorithm needs a sample every minute.
const unsigned long SLEEP_TIME = 60000; 

const char *weather[] = { "stable", "sunny", "cloudy", "unstable", "thunderstorm", "unknown" };
enum FORECAST
{
  STABLE = 0,     // "Stable Weather Pattern"
  SUNNY = 1,      // "Slowly rising Good Weather", "Clear/Sunny "
  CLOUDY = 2,     // "Slowly falling L-Pressure ", "Cloudy/Rain "
  UNSTABLE = 3,   // "Quickly rising H-Press",     "Not Stable"
  THUNDERSTORM = 4, // "Quickly falling L-Press",    "Thunderstorm"
  UNKNOWN = 5     // "Unknown (More Time needed)
};

float lastPressure = -1;
float lastTemp = -1;
float lastHum = -1;
int lastForecast = -1;

const int LAST_SAMPLES_COUNT = 5;
float lastPressureSamples[LAST_SAMPLES_COUNT];


// this CONVERSION_FACTOR is used to convert from Pa to kPa in the forecast algorithm
// get kPa/h by dividing hPa by 10 
#define CONVERSION_FACTOR (1.0/10.0)

int minuteCount = 0;
bool firstRound = true;
// average value is used in forecast algorithm.
float pressureAvg;
// average after 2 hours is used as reference value for the next iteration.
float pressureAvg2;

float dP_dt;
boolean metric;
MyMessage tempMsg(TEMP_CHILD, V_TEMP);
MyMessage humMsg(HUM_CHILD, V_HUM);
MyMessage pressureMsg(BARO_CHILD, V_PRESSURE);
MyMessage forecastMsg(BARO_CHILD, V_FORECAST);


float getLastPressureSamplesAverage()
{
  float lastPressureSamplesAverage = 0;
  for (int i = 0; i < LAST_SAMPLES_COUNT; i++)
  {
    lastPressureSamplesAverage += lastPressureSamples[i];
  }
  lastPressureSamplesAverage /= LAST_SAMPLES_COUNT;

  return lastPressureSamplesAverage;
}


// Algorithm found here
// http://www.freescale.com/files/sensors/doc/app_note/AN3914.pdf
// Pressure in hPa -->  forecast done by calculating kPa/h
int sample(float pressure)
{
  // Calculate the average of the last n minutes.
  int index = minuteCount % LAST_SAMPLES_COUNT;
  lastPressureSamples[index] = pressure;

  minuteCount++;
  if (minuteCount > 185)
  {
    minuteCount = 6;
  }

  if (minuteCount == 5)
  {
    pressureAvg = getLastPressureSamplesAverage();
  }
  else if (minuteCount == 35)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change * 2; // note this is for t = 0.5hour
    }
    else
    {
      dP_dt = change / 1.5; // divide by 1.5 as this is the difference in time from 0 value.
    }
  }
  else if (minuteCount == 65)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) //first time initial 3 hour
    {
      dP_dt = change; //note this is for t = 1 hour
    }
    else
    {
      dP_dt = change / 2; //divide by 2 as this is the difference in time from 0 value
    }
  }
  else if (minuteCount == 95)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change / 1.5; // note this is for t = 1.5 hour
    }
    else
    {
      dP_dt = change / 2.5; // divide by 2.5 as this is the difference in time from 0 value
    }
  }
  else if (minuteCount == 125)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    pressureAvg2 = lastPressureAvg; // store for later use.
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change / 2; // note this is for t = 2 hour
    }
    else
    {
      dP_dt = change / 3; // divide by 3 as this is the difference in time from 0 value
    }
  }
  else if (minuteCount == 155)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change / 2.5; // note this is for t = 2.5 hour
    }
    else
    {
      dP_dt = change / 3.5; // divide by 3.5 as this is the difference in time from 0 value
    }
  }
  else if (minuteCount == 185)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change / 3; // note this is for t = 3 hour
    }
    else
    {
      dP_dt = change / 4; // divide by 4 as this is the difference in time from 0 value
    }
    pressureAvg = pressureAvg2; // Equating the pressure at 0 to the pressure at 2 hour after 3 hours have past.
    firstRound = false; // flag to let you know that this is on the past 3 hour mark. Initialized to 0 outside main loop.
  }

  int forecast = UNKNOWN;
  if (minuteCount < 35 && firstRound) //if time is less than 35 min on the first 3 hour interval.
  {
    forecast = UNKNOWN;
  }
  else if (dP_dt < (-0.25))
  {
    forecast = THUNDERSTORM;
  }
  else if (dP_dt > 0.25)
  {
    forecast = UNSTABLE;
  }
  else if ((dP_dt > (-0.25)) && (dP_dt < (-0.05)))
  {
    forecast = CLOUDY;
  }
  else if ((dP_dt > 0.05) && (dP_dt < 0.25))
  {
    forecast = SUNNY;
  }
  else if ((dP_dt >(-0.05)) && (dP_dt < 0.05))
  {
    forecast = STABLE;
  }
  else
  {
    forecast = UNKNOWN;
  }

  // uncomment when debugging
  //Serial.print(F("Forecast at minute "));
  //Serial.print(minuteCount);
  //Serial.print(F(" dP/dt = "));
  //Serial.print(dP_dt);
  //Serial.print(F("kPa/h --> "));
  //Serial.println(weather[forecast]);

  return forecast;
}


void setup() {
  metric = getControllerConfig().isMetric;  // was getConfig().isMetric; before MySensors v2.1.1
  Wire.begin(); // Wire.begin(sda, scl)
}

void presentation()  {
  // Send the sketch version information to the gateway and Controller
  sendSketchInfo("BME280 Sensor", "1.6");

  // Register sensors to gw (they will be created as child devices)
  present(BARO_CHILD, S_BARO);
  present(TEMP_CHILD, S_TEMP);
  present(HUM_CHILD, S_HUM);
}

// Loop
void loop() {
  
  // need to read the NVM compensation parameters
  BME280.readCompensationParams();

  /* After taking the measurement the chip goes back to sleep, use when battery powered.
  // Oversampling settings (os1x, os2x, os4x, os8x or os16x).
  BME280.writeFilterCoefficient(fc_16);       // IIR Filter coefficient, higher numbers avoid sudden changes to be accounted for (such as slamming a door)
  BME280.writeOversamplingPressure(os16x);    // pressure x16
  BME280.writeOversamplingTemperature(os8x);  // temperature x8
  BME280.writeOversamplingHumidity(os8x);     // humidity x8

  BME280.writeMode(smForced);                 // Forced sample.  After taking the measurement the chip goes back to sleep
  */

  // Normal mode for regular automatic samples
  BME280.writeStandbyTime(tsb_0p5ms);         // tsb = 0.5ms
  BME280.writeFilterCoefficient(fc_16);       // IIR Filter coefficient 16
  BME280.writeOversamplingPressure(os16x);    // pressure x16
  BME280.writeOversamplingTemperature(os8x);  // temperature x8
  BME280.writeOversamplingHumidity(os8x);     // humidity x8
  
  BME280.writeMode(smNormal);
  
  while (1) {
    // Just to be sure, wait until sensor is done mesuring  
    while (BME280.isMeasuring()) {
  }
  
  // Read out the data - must do this before calling the getxxxxx routines
  BME280.readMeasurements();

  float temperature = BME280.getTemperatureMostAccurate();                    // must get temp first
  float humidity = BME280.getHumidityMostAccurate();
  float pressure_local = BME280.getPressureMostAccurate();                    // Get pressure at current location
  float pressure = pressure_local/pow((1.0 - ( ALTITUDE / 44330.0 )), 5.255); // Adjust to sea level pressure using user altitude
  int forecast = sample(pressure);
  
  if (!metric) 
  {
    // Convert to fahrenheit
    temperature = temperature * 9.0 / 5.0 + 32.0;
  }

  Serial.println();
  Serial.print("Temperature = ");
  Serial.print(temperature);
  Serial.println(metric ? " °C" : " °F");
  Serial.print("Humidity = ");
  Serial.print(humidity);
  Serial.println(" %");
  Serial.print("Pressure = ");
  Serial.print(pressure);
  Serial.println(" hPa");
  Serial.print("Forecast = ");
  Serial.println(weather[forecast]);
  Serial.println();


  if (temperature != lastTemp) 
  {
    send(tempMsg.set(temperature, 1));
    lastTemp = temperature;
  }


  if (humidity != lastHum) 
  {
    send(humMsg.set(humidity, 1));
    lastHum = humidity;
  }

  if (pressure != lastPressure) 
  {
    send(pressureMsg.set(pressure, 2));
    lastPressure = pressure;
  }

  if (forecast != lastForecast)
  {
    send(forecastMsg.set(weather[forecast]));
    lastForecast = forecast;
  }
  
  sleep(SLEEP_TIME);
  
}
}

[Zbigniew Ko]

@yoshida Thank you very much.
As soon as I find time I will check it out.

Yes checked, sketch works.
Thanks yoshida.
Please note that the library BME_MOD-1022.h consists of two parts: file-h, and file cpp.

[gohan]

I am using the one from adafruit : what's the difference with this other library?

[alexsh1]

@gohan I have been using both libraries with a chinese module I bought from Aliexpress. I did not notice any differences apart from size and maybe a module address, which you can change in either library.

[bluezr1]

I used the last sketch posed by Yoshida and for some reason whenever the temp and humidity goes through a stretch where there isn't any change, it's as if the node goes into a deep sleep and doesn't come out of it until I hit the reset on a pro mini.

I have it plunged in and not on batteries, so no need for any deep sleep. Is there anything I can change in the sketch? I'm still fairly new at this, although I'm having a blast.

Thanks,

[yoshida]

@bluezr1 Interesting... :) I used it with a pro mini as well, and my problem was that it ate up the batteries in 2 weeks... :D So I would need more deep sleep for the same sketch :D

But for that 2 weeks, it was working well. Temp/Hum/Baro updated every minute.

[mfalkvidd]

@yoshida did you do the modifications (remove led and regulator) recommended at https://www.mysensors.org/build/battery ?

My storage room sensor (https://forum.mysensors.org/topic/7227/esp8266-wifi-gateway-with-rssi-for-rfm69-and-wifi ) uses the bme280. Not sure if that sketch is any help, but you are welcome to use it. It is much much simpler than the sketch posted above though.

[yoshida]

@mfalkvidd good question, yes I have removed the two leds I found, but I am too lame to remove the voltage regulator :( I have read here that the most consuming part is the LED(s)

[scalpel]

@yoshida said in BME280 temp/humidity/pressure sensor:

> /**
>  * The MySensors Arduino library handles the wireless radio link and protocol
>  * between your home built sensors/actuators and HA controller of choice.
>  * The sensors forms a self healing radio network with optional repeaters. Each
>  * repeater and gateway builds a routing tables in EEPROM which keeps track of the
>  * network topology allowing messages to be routed to nodes.
>  *
>  * Created by Henrik Ekblad <henrik.ekblad@mysensors.org>
>  * Copyright (C) 2013-2015 Sensnology AB
>  * Full contributor list: https://github.com/mysensors/Arduino/graphs/contributors
>  *
>  * Documentation: http://www.mysensors.org
>  * Support Forum: http://forum.mysensors.org
>  *
>  * This program is free software; you can redistribute it and/or
>  * modify it under the terms of the GNU General Public License
>  * version 2 as published by the Free Software Foundation.
>  *
>  *******************************
>  *
>  * REVISION HISTORY
>  * Version 1.0 - Henrik Ekblad
>  * 
>  * DESCRIPTION
>  * Pressure sensor example using BMP085 module  
>  * http://www.mysensors.org/build/pressure
>  *
>  */
> 
> // Enable debug prints to serial monitor
> #define MY_DEBUG 
> 
> // Enable and select radio type attached
> #define MY_RADIO_NRF24
> //#define MY_RADIO_RFM69
> 
> #include <SPI.h>
> #include <MySensors.h>  
> #include <Wire.h>
> 
> // BME280 libraries and variables
> // Bosch BME280 Embedded Adventures MOD-1022 weather multi-sensor Arduino code
> // Written originally by Embedded Adventures
> // https://github.com/embeddedadventures/BME280
> #include <BME280_MOD-1022.h>
> 
> #define BARO_CHILD 0
> #define TEMP_CHILD 1
> #define HUM_CHILD 2
> 
> const float ALTITUDE = 184; // <-- adapt this value to your location's altitude (in m). Use your smartphone GPS to get an accurate value!
> 
> // Sleep time between reads (in ms). Do not change this value as the forecast algorithm needs a sample every minute.
> const unsigned long SLEEP_TIME = 60000; 
> 
> const char *weather[] = { "stable", "sunny", "cloudy", "unstable", "thunderstorm", "unknown" };
> enum FORECAST
> {
>   STABLE = 0,     // "Stable Weather Pattern"
>   SUNNY = 1,      // "Slowly rising Good Weather", "Clear/Sunny "
>   CLOUDY = 2,     // "Slowly falling L-Pressure ", "Cloudy/Rain "
>   UNSTABLE = 3,   // "Quickly rising H-Press",     "Not Stable"
>   THUNDERSTORM = 4, // "Quickly falling L-Press",    "Thunderstorm"
>   UNKNOWN = 5     // "Unknown (More Time needed)
> };
> 
> float lastPressure = -1;
> float lastTemp = -1;
> float lastHum = -1;
> int lastForecast = -1;
> 
> const int LAST_SAMPLES_COUNT = 5;
> float lastPressureSamples[LAST_SAMPLES_COUNT];
> 
> 
> // this CONVERSION_FACTOR is used to convert from Pa to kPa in the forecast algorithm
> // get kPa/h by dividing hPa by 10 
> #define CONVERSION_FACTOR (1.0/10.0)
> 
> int minuteCount = 0;
> bool firstRound = true;
> // average value is used in forecast algorithm.
> float pressureAvg;
> // average after 2 hours is used as reference value for the next iteration.
> float pressureAvg2;
> 
> float dP_dt;
> boolean metric;
> MyMessage tempMsg(TEMP_CHILD, V_TEMP);
> MyMessage humMsg(HUM_CHILD, V_HUM);
> MyMessage pressureMsg(BARO_CHILD, V_PRESSURE);
> MyMessage forecastMsg(BARO_CHILD, V_FORECAST);
> 
> 
> float getLastPressureSamplesAverage()
> {
>   float lastPressureSamplesAverage = 0;
>   for (int i = 0; i < LAST_SAMPLES_COUNT; i++)
>   {
>     lastPressureSamplesAverage += lastPressureSamples[i];
>   }
>   lastPressureSamplesAverage /= LAST_SAMPLES_COUNT;
> 
>   return lastPressureSamplesAverage;
> }
> 
> 
> // Algorithm found here
> // http://www.freescale.com/files/sensors/doc/app_note/AN3914.pdf
> // Pressure in hPa -->  forecast done by calculating kPa/h
> int sample(float pressure)
> {
>   // Calculate the average of the last n minutes.
>   int index = minuteCount % LAST_SAMPLES_COUNT;
>   lastPressureSamples[index] = pressure;
> 
>   minuteCount++;
>   if (minuteCount > 185)
>   {
>     minuteCount = 6;
>   }
> 
>   if (minuteCount == 5)
>   {
>     pressureAvg = getLastPressureSamplesAverage();
>   }
>   else if (minuteCount == 35)
>   {
>     float lastPressureAvg = getLastPressureSamplesAverage();
>     float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
>     if (firstRound) // first time initial 3 hour
>     {
>       dP_dt = change * 2; // note this is for t = 0.5hour
>     }
>     else
>     {
>       dP_dt = change / 1.5; // divide by 1.5 as this is the difference in time from 0 value.
>     }
>   }
>   else if (minuteCount == 65)
>   {
>     float lastPressureAvg = getLastPressureSamplesAverage();
>     float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
>     if (firstRound) //first time initial 3 hour
>     {
>       dP_dt = change; //note this is for t = 1 hour
>     }
>     else
>     {
>       dP_dt = change / 2; //divide by 2 as this is the difference in time from 0 value
>     }
>   }
>   else if (minuteCount == 95)
>   {
>     float lastPressureAvg = getLastPressureSamplesAverage();
>     float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
>     if (firstRound) // first time initial 3 hour
>     {
>       dP_dt = change / 1.5; // note this is for t = 1.5 hour
>     }
>     else
>     {
>       dP_dt = change / 2.5; // divide by 2.5 as this is the difference in time from 0 value
>     }
>   }
>   else if (minuteCount == 125)
>   {
>     float lastPressureAvg = getLastPressureSamplesAverage();
>     pressureAvg2 = lastPressureAvg; // store for later use.
>     float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
>     if (firstRound) // first time initial 3 hour
>     {
>       dP_dt = change / 2; // note this is for t = 2 hour
>     }
>     else
>     {
>       dP_dt = change / 3; // divide by 3 as this is the difference in time from 0 value
>     }
>   }
>   else if (minuteCount == 155)
>   {
>     float lastPressureAvg = getLastPressureSamplesAverage();
>     float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
>     if (firstRound) // first time initial 3 hour
>     {
>       dP_dt = change / 2.5; // note this is for t = 2.5 hour
>     }
>     else
>     {
>       dP_dt = change / 3.5; // divide by 3.5 as this is the difference in time from 0 value
>     }
>   }
>   else if (minuteCount == 185)
>   {
>     float lastPressureAvg = getLastPressureSamplesAverage();
>     float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
>     if (firstRound) // first time initial 3 hour
>     {
>       dP_dt = change / 3; // note this is for t = 3 hour
>     }
>     else
>     {
>       dP_dt = change / 4; // divide by 4 as this is the difference in time from 0 value
>     }
>     pressureAvg = pressureAvg2; // Equating the pressure at 0 to the pressure at 2 hour after 3 hours have past.
>     firstRound = false; // flag to let you know that this is on the past 3 hour mark. Initialized to 0 outside main loop.
>   }
> 
>   int forecast = UNKNOWN;
>   if (minuteCount < 35 && firstRound) //if time is less than 35 min on the first 3 hour interval.
>   {
>     forecast = UNKNOWN;
>   }
>   else if (dP_dt < (-0.25))
>   {
>     forecast = THUNDERSTORM;
>   }
>   else if (dP_dt > 0.25)
>   {
>     forecast = UNSTABLE;
>   }
>   else if ((dP_dt > (-0.25)) && (dP_dt < (-0.05)))
>   {
>     forecast = CLOUDY;
>   }
>   else if ((dP_dt > 0.05) && (dP_dt < 0.25))
>   {
>     forecast = SUNNY;
>   }
>   else if ((dP_dt >(-0.05)) && (dP_dt < 0.05))
>   {
>     forecast = STABLE;
>   }
>   else
>   {
>     forecast = UNKNOWN;
>   }
> 
>   // uncomment when debugging
>   //Serial.print(F("Forecast at minute "));
>   //Serial.print(minuteCount);
>   //Serial.print(F(" dP/dt = "));
>   //Serial.print(dP_dt);
>   //Serial.print(F("kPa/h --> "));
>   //Serial.println(weather[forecast]);
> 
>   return forecast;
> }
> 
> 
> void setup() {
>   metric = getControllerConfig().isMetric;  // was getConfig().isMetric; before MySensors v2.1.1
>   Wire.begin(); // Wire.begin(sda, scl)
> }
> 
> void presentation()  {
>   // Send the sketch version information to the gateway and Controller
>   sendSketchInfo("BME280 Sensor", "1.6");
> 
>   // Register sensors to gw (they will be created as child devices)
>   present(BARO_CHILD, S_BARO);
>   present(TEMP_CHILD, S_TEMP);
>   present(HUM_CHILD, S_HUM);
> }
> 
> // Loop
> void loop() {
>   
>   // need to read the NVM compensation parameters
>   BME280.readCompensationParams();
> 
>   /* After taking the measurement the chip goes back to sleep, use when battery powered.
>   // Oversampling settings (os1x, os2x, os4x, os8x or os16x).
>   BME280.writeFilterCoefficient(fc_16);       // IIR Filter coefficient, higher numbers avoid sudden changes to be accounted for (such as slamming a door)
>   BME280.writeOversamplingPressure(os16x);    // pressure x16
>   BME280.writeOversamplingTemperature(os8x);  // temperature x8
>   BME280.writeOversamplingHumidity(os8x);     // humidity x8
> 
>   BME280.writeMode(smForced);                 // Forced sample.  After taking the measurement the chip goes back to sleep
>   */
> 
>   // Normal mode for regular automatic samples
>   BME280.writeStandbyTime(tsb_0p5ms);         // tsb = 0.5ms
>   BME280.writeFilterCoefficient(fc_16);       // IIR Filter coefficient 16
>   BME280.writeOversamplingPressure(os16x);    // pressure x16
>   BME280.writeOversamplingTemperature(os8x);  // temperature x8
>   BME280.writeOversamplingHumidity(os8x);     // humidity x8
>   
>   BME280.writeMode(smNormal);
>   
>   while (1) {
>     // Just to be sure, wait until sensor is done mesuring  
>     while (BME280.isMeasuring()) {
>   }
>   
>   // Read out the data - must do this before calling the getxxxxx routines
>   BME280.readMeasurements();
> 
>   float temperature = BME280.getTemperatureMostAccurate();                    // must get temp first
>   float humidity = BME280.getHumidityMostAccurate();
>   float pressure_local = BME280.getPressureMostAccurate();                    // Get pressure at current location
>   float pressure = pressure_local/pow((1.0 - ( ALTITUDE / 44330.0 )), 5.255); // Adjust to sea level pressure using user altitude
>   int forecast = sample(pressure);
>   
>   if (!metric) 
>   {
>     // Convert to fahrenheit
>     temperature = temperature * 9.0 / 5.0 + 32.0;
>   }
> 
>   Serial.println();
>   Serial.print("Temperature = ");
>   Serial.print(temperature);
>   Serial.println(metric ? " °C" : " °F");
>   Serial.print("Humidity = ");
>   Serial.print(humidity);
>   Serial.println(" %");
>   Serial.print("Pressure = ");
>   Serial.print(pressure);
>   Serial.println(" hPa");
>   Serial.print("Forecast = ");
>   Serial.println(weather[forecast]);
>   Serial.println();
> 
> 
>   if (temperature != lastTemp) 
>   {
>     send(tempMsg.set(temperature, 1));
>     lastTemp = temperature;
>   }
> 
> 
>   if (humidity != lastHum) 
>   {
>     send(humMsg.set(humidity, 1));
>     lastHum = humidity;
>   }
> 
>   if (pressure != lastPressure) 
>   {
>     send(pressureMsg.set(pressure, 2));
>     lastPressure = pressure;
>   }
> 
>   if (forecast != lastForecast)
>   {
>     send(forecastMsg.set(weather[forecast]));
>     lastForecast = forecast;
>   }
>   
>   sleep(SLEEP_TIME);
>   
> }
> }

Added to sketch @yoshida battery state send, but its not sending it, please chek it:

/**
 * The MySensors Arduino library handles the wireless radio link and protocol
 * between your home built sensors/actuators and HA controller of choice.
 * The sensors forms a self healing radio network with optional repeaters. Each
 * repeater and gateway builds a routing tables in EEPROM which keeps track of the
 * network topology allowing messages to be routed to nodes.
 *
 * Created by Henrik Ekblad <henrik.ekblad@mysensors.org>
 * Copyright (C) 2013-2015 Sensnology AB
 * Full contributor list: https://github.com/mysensors/Arduino/graphs/contributors
 *
 * Documentation: http://www.mysensors.org
 * Support Forum: http://forum.mysensors.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 *******************************
 *
 * REVISION HISTORY
 * Version 1.0 - Henrik Ekblad
 * 
 * DESCRIPTION
 * Pressure sensor example using BMP085 module  
 * http://www.mysensors.org/build/pressure
 *
 */

// Enable debug prints to serial monitor
#define MY_DEBUG 

// Enable and select radio type attached
#define MY_RADIO_NRF24
//#define MY_RADIO_RFM69

#include <SPI.h>
#include <MySensors.h>  
#include <Wire.h>

// BME280 libraries and variables
// Bosch BME280 Embedded Adventures MOD-1022 weather multi-sensor Arduino code
// Written originally by Embedded Adventures
// https://github.com/embeddedadventures/BME280
#include <BME280_MOD-1022.h>

#define BARO_CHILD 0
#define TEMP_CHILD 1
#define HUM_CHILD 2

int BATTERY_SENSE_PIN = A0; // select the input pin for the battery sense point
int oldBatteryPcnt = 0;

const float ALTITUDE = 450; // <-- adapt this value to your location's altitude (in m). Use your smartphone GPS to get an accurate value!

// Sleep time between reads (in ms). Do not change this value as the forecast algorithm needs a sample every minute.
const unsigned long SLEEP_TIME = 300000; 

const char *weather[] = { "stable", "sunny", "cloudy", "unstable", "thunderstorm", "unknown" };
enum FORECAST
{
  STABLE = 0,     // "Stable Weather Pattern"
  SUNNY = 1,      // "Slowly rising Good Weather", "Clear/Sunny "
  CLOUDY = 2,     // "Slowly falling L-Pressure ", "Cloudy/Rain "
  UNSTABLE = 3,   // "Quickly rising H-Press",     "Not Stable"
  THUNDERSTORM = 4, // "Quickly falling L-Press",    "Thunderstorm"
  UNKNOWN = 5     // "Unknown (More Time needed)
};

float lastPressure = -1;
float lastTemp = -1;
float lastHum = -1;
int lastForecast = -1;

const int LAST_SAMPLES_COUNT = 5;
float lastPressureSamples[LAST_SAMPLES_COUNT];


// this CONVERSION_FACTOR is used to convert from Pa to kPa in the forecast algorithm
// get kPa/h by dividing hPa by 10 
#define CONVERSION_FACTOR (1.0/10.0)

int minuteCount = 0;
bool firstRound = true;
// average value is used in forecast algorithm.
float pressureAvg;
// average after 2 hours is used as reference value for the next iteration.
float pressureAvg2;

float dP_dt;
boolean metric;
MyMessage tempMsg(TEMP_CHILD, V_TEMP);
MyMessage humMsg(HUM_CHILD, V_HUM);
MyMessage pressureMsg(BARO_CHILD, V_PRESSURE);
MyMessage forecastMsg(BARO_CHILD, V_FORECAST);


float getLastPressureSamplesAverage()
{
  float lastPressureSamplesAverage = 0;
  for (int i = 0; i < LAST_SAMPLES_COUNT; i++)
  {
    lastPressureSamplesAverage += lastPressureSamples[i];
  }
  lastPressureSamplesAverage /= LAST_SAMPLES_COUNT;

  return lastPressureSamplesAverage;
}


// Algorithm found here
// http://www.freescale.com/files/sensors/doc/app_note/AN3914.pdf
// Pressure in hPa -->  forecast done by calculating kPa/h
int sample(float pressure)
{
  // Calculate the average of the last n minutes.
  int index = minuteCount % LAST_SAMPLES_COUNT;
  lastPressureSamples[index] = pressure;

  minuteCount++;
  if (minuteCount > 185)
  {
    minuteCount = 6;
  }

  if (minuteCount == 5)
  {
    pressureAvg = getLastPressureSamplesAverage();
  }
  else if (minuteCount == 35)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change * 2; // note this is for t = 0.5hour
    }
    else
    {
      dP_dt = change / 1.5; // divide by 1.5 as this is the difference in time from 0 value.
    }
  }
  else if (minuteCount == 65)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) //first time initial 3 hour
    {
      dP_dt = change; //note this is for t = 1 hour
    }
    else
    {
      dP_dt = change / 2; //divide by 2 as this is the difference in time from 0 value
    }
  }
  else if (minuteCount == 95)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change / 1.5; // note this is for t = 1.5 hour
    }
    else
    {
      dP_dt = change / 2.5; // divide by 2.5 as this is the difference in time from 0 value
    }
  }
  else if (minuteCount == 125)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    pressureAvg2 = lastPressureAvg; // store for later use.
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change / 2; // note this is for t = 2 hour
    }
    else
    {
      dP_dt = change / 3; // divide by 3 as this is the difference in time from 0 value
    }
  }
  else if (minuteCount == 155)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change / 2.5; // note this is for t = 2.5 hour
    }
    else
    {
      dP_dt = change / 3.5; // divide by 3.5 as this is the difference in time from 0 value
    }
  }
  else if (minuteCount == 185)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change / 3; // note this is for t = 3 hour
    }
    else
    {
      dP_dt = change / 4; // divide by 4 as this is the difference in time from 0 value
    }
    pressureAvg = pressureAvg2; // Equating the pressure at 0 to the pressure at 2 hour after 3 hours have past.
    firstRound = false; // flag to let you know that this is on the past 3 hour mark. Initialized to 0 outside main loop.
  }

  int forecast = UNKNOWN;
  if (minuteCount < 35 && firstRound) //if time is less than 35 min on the first 3 hour interval.
  {
    forecast = UNKNOWN;
  }
  else if (dP_dt < (-0.25))
  {
    forecast = THUNDERSTORM;
  }
  else if (dP_dt > 0.25)
  {
    forecast = UNSTABLE;
  }
  else if ((dP_dt > (-0.25)) && (dP_dt < (-0.05)))
  {
    forecast = CLOUDY;
  }
  else if ((dP_dt > 0.05) && (dP_dt < 0.25))
  {
    forecast = SUNNY;
  }
  else if ((dP_dt >(-0.05)) && (dP_dt < 0.05))
  {
    forecast = STABLE;
  }
  else
  {
    forecast = UNKNOWN;
  }

  // uncomment when debugging
  //Serial.print(F("Forecast at minute "));
  //Serial.print(minuteCount);
  //Serial.print(F(" dP/dt = "));
  //Serial.print(dP_dt);
  //Serial.print(F("kPa/h --> "));
  //Serial.println(weather[forecast]);

  return forecast;
}


void setup() {
  metric = getControllerConfig().isMetric;  // was getConfig().isMetric; before MySensors v2.1.1
  Wire.begin(); // Wire.begin(sda, scl)
  // use the 1.1 V internal reference
  #if defined(__AVR_ATmega2560__)
  analogReference(INTERNAL1V1);
  #else
  analogReference(INTERNAL);
  #endif
}

void presentation()  {
  // Send the sketch version information to the gateway and Controller
  sendSketchInfo("BME280 Sensor", "1.6");

  // Register sensors to gw (they will be created as child devices)
  present(BARO_CHILD, S_BARO);
  present(TEMP_CHILD, S_TEMP);
  present(HUM_CHILD, S_HUM);
}

// Loop
void loop() {

  
  
  // need to read the NVM compensation parameters
  BME280.readCompensationParams();

  /* After taking the measurement the chip goes back to sleep, use when battery powered.
  // Oversampling settings (os1x, os2x, os4x, os8x or os16x).
  BME280.writeFilterCoefficient(fc_16);       // IIR Filter coefficient, higher numbers avoid sudden changes to be accounted for (such as slamming a door)
  BME280.writeOversamplingPressure(os16x);    // pressure x16
  BME280.writeOversamplingTemperature(os8x);  // temperature x8
  BME280.writeOversamplingHumidity(os8x);     // humidity x8

  BME280.writeMode(smForced);                 // Forced sample.  After taking the measurement the chip goes back to sleep
  */

  // Normal mode for regular automatic samples
  BME280.writeStandbyTime(tsb_0p5ms);         // tsb = 0.5ms
  BME280.writeFilterCoefficient(fc_16);       // IIR Filter coefficient 16
  BME280.writeOversamplingPressure(os16x);    // pressure x16
  BME280.writeOversamplingTemperature(os8x);  // temperature x8
  BME280.writeOversamplingHumidity(os8x);     // humidity x8
  
  BME280.writeMode(smNormal);
  
  while (1) {
    // Just to be sure, wait until sensor is done mesuring  
    while (BME280.isMeasuring()) {
  }
  
  // Read out the data - must do this before calling the getxxxxx routines
  BME280.readMeasurements();

  float temperature = BME280.getTemperatureMostAccurate();                    // must get temp first
  float humidity = BME280.getHumidityMostAccurate();
  float pressure_local = BME280.getPressureMostAccurate();                    // Get pressure at current location
  float pressure = pressure_local/pow((1.0 - ( ALTITUDE / 44330.0 )), 5.255); // Adjust to sea level pressure using user altitude
  int forecast = sample(pressure);
  
  if (!metric) 
  {
    // Convert to fahrenheit
    temperature = temperature * 9.0 / 5.0 + 32.0;
  }

  Serial.println();
  Serial.print("Temperature = ");
  Serial.print(temperature);
  Serial.println(metric ? " °C" : " °F");
  Serial.print("Humidity = ");
  Serial.print(humidity);
  Serial.println(" %");
  Serial.print("Pressure = ");
  Serial.print(pressure);
  Serial.println(" hPa");
  Serial.print("Forecast = ");
  Serial.println(weather[forecast]);
  Serial.println();


  if (temperature != lastTemp) 
  {
    send(tempMsg.set(temperature, 1));
    lastTemp = temperature;
  }


  if (humidity != lastHum) 
  {
    send(humMsg.set(humidity, 1));
    lastHum = humidity;
  }

  if (pressure != lastPressure) 
  {
    send(pressureMsg.set(pressure, 2));
    lastPressure = pressure;
  }

  if (forecast != lastForecast)
  {
    send(forecastMsg.set(weather[forecast]));
    lastForecast = forecast;
  }

    int sensorValue = analogRead(BATTERY_SENSE_PIN);
    int batteryPcnt = sensorValue / 10;
    if (oldBatteryPcnt != batteryPcnt) {
    // Power up radio after sleep
    sendBatteryLevel(batteryPcnt);
    oldBatteryPcnt = batteryPcnt;
    }
    
  sleep(SLEEP_TIME);
  
}
}

[sundberg84]

@scalpel - works great! Thank you!!
Downloaded the library from the link in your sketch and up and running i no time.
Here is my sketch, with some modifications:

• Lightsensor A0
• No sleep (might want to enable repeater function later)
• Sends every 5 minute regardless of prevoius value (I use Domoticz and want to avoid red nodes and combined nodes).
• Fixed node it

// Enable debug prints to serial monitor
//#define MY_DEBUG 

// Enable and select radio type attached
#define MY_RADIO_NRF24
//#define MY_RADIO_RFM69

//Fixed ID/Parent?
#define MY_NODE_ID 20                     //To set a fixed ID for your node
//#define MY_PARENT_NODE_ID 100             //To set a fixed parent for this node

#include <SPI.h>
#include <MySensors.h>  
#include <Wire.h>

// BME280 libraries and variables
// Bosch BME280 Embedded Adventures MOD-1022 weather multi-sensor Arduino code
// Written originally by Embedded Adventures
// https://github.com/embeddedadventures/BME280
#include <BME280_MOD-1022.h>

#define BARO_CHILD 0
#define TEMP_CHILD 1
#define HUM_CHILD 2

long interval = 300000;           // interval at which to send (milliseconds)
long previousMillis = interval;        // will store last time data was sent

const float ALTITUDE = 135; // <-- adapt this value to your location's altitude (in m). Use your smartphone GPS to get an accurate value!

const char *weather[] = { "stable", "sunny", "cloudy", "unstable", "thunderstorm", "unknown" };
enum FORECAST
{
  STABLE = 0,     // "Stable Weather Pattern"
  SUNNY = 1,      // "Slowly rising Good Weather", "Clear/Sunny "
  CLOUDY = 2,     // "Slowly falling L-Pressure ", "Cloudy/Rain "
  UNSTABLE = 3,   // "Quickly rising H-Press",     "Not Stable"
  THUNDERSTORM = 4, // "Quickly falling L-Press",    "Thunderstorm"
  UNKNOWN = 5     // "Unknown (More Time needed)
};


const int LAST_SAMPLES_COUNT = 5;
float lastPressureSamples[LAST_SAMPLES_COUNT];


// this CONVERSION_FACTOR is used to convert from Pa to kPa in the forecast algorithm
// get kPa/h by dividing hPa by 10 
#define CONVERSION_FACTOR (1.0/10.0)

int minuteCount = 0;
bool firstRound = true;
// average value is used in forecast algorithm.
float pressureAvg;
// average after 2 hours is used as reference value for the next iteration.
float pressureAvg2;

float dP_dt;
boolean metric;
MyMessage tempMsg(TEMP_CHILD, V_TEMP);
MyMessage humMsg(HUM_CHILD, V_HUM);
MyMessage pressureMsg(BARO_CHILD, V_PRESSURE);
MyMessage forecastMsg(BARO_CHILD, V_FORECAST);

//Light
#define CHILD_ID_LIGHT 3
#define LIGHT_SENSOR_ANALOG_PIN A0
MyMessage light_Msg(CHILD_ID_LIGHT, V_LIGHT_LEVEL);


float getLastPressureSamplesAverage()
{
  float lastPressureSamplesAverage = 0;
  for (int i = 0; i < LAST_SAMPLES_COUNT; i++)
  {
    lastPressureSamplesAverage += lastPressureSamples[i];
  }
  lastPressureSamplesAverage /= LAST_SAMPLES_COUNT;

  return lastPressureSamplesAverage;
}


// Algorithm found here
// http://www.freescale.com/files/sensors/doc/app_note/AN3914.pdf
// Pressure in hPa -->  forecast done by calculating kPa/h
int sample(float pressure)
{
  // Calculate the average of the last n minutes.
  int index = minuteCount % LAST_SAMPLES_COUNT;
  lastPressureSamples[index] = pressure;

  minuteCount++;
  if (minuteCount > 185)
  {
    minuteCount = 6;
  }

  if (minuteCount == 5)
  {
    pressureAvg = getLastPressureSamplesAverage();
  }
  else if (minuteCount == 35)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change * 2; // note this is for t = 0.5hour
    }
    else
    {
      dP_dt = change / 1.5; // divide by 1.5 as this is the difference in time from 0 value.
    }
  }
  else if (minuteCount == 65)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) //first time initial 3 hour
    {
      dP_dt = change; //note this is for t = 1 hour
    }
    else
    {
      dP_dt = change / 2; //divide by 2 as this is the difference in time from 0 value
    }
  }
  else if (minuteCount == 95)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change / 1.5; // note this is for t = 1.5 hour
    }
    else
    {
      dP_dt = change / 2.5; // divide by 2.5 as this is the difference in time from 0 value
    }
  }
  else if (minuteCount == 125)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    pressureAvg2 = lastPressureAvg; // store for later use.
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change / 2; // note this is for t = 2 hour
    }
    else
    {
      dP_dt = change / 3; // divide by 3 as this is the difference in time from 0 value
    }
  }
  else if (minuteCount == 155)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change / 2.5; // note this is for t = 2.5 hour
    }
    else
    {
      dP_dt = change / 3.5; // divide by 3.5 as this is the difference in time from 0 value
    }
  }
  else if (minuteCount == 185)
  {
    float lastPressureAvg = getLastPressureSamplesAverage();
    float change = (lastPressureAvg - pressureAvg) * CONVERSION_FACTOR;
    if (firstRound) // first time initial 3 hour
    {
      dP_dt = change / 3; // note this is for t = 3 hour
    }
    else
    {
      dP_dt = change / 4; // divide by 4 as this is the difference in time from 0 value
    }
    pressureAvg = pressureAvg2; // Equating the pressure at 0 to the pressure at 2 hour after 3 hours have past.
    firstRound = false; // flag to let you know that this is on the past 3 hour mark. Initialized to 0 outside main loop.
  }

  int forecast = UNKNOWN;
  if (minuteCount < 35 && firstRound) //if time is less than 35 min on the first 3 hour interval.
  {
    forecast = UNKNOWN;
  }
  else if (dP_dt < (-0.25))
  {
    forecast = THUNDERSTORM;
  }
  else if (dP_dt > 0.25)
  {
    forecast = UNSTABLE;
  }
  else if ((dP_dt > (-0.25)) && (dP_dt < (-0.05)))
  {
    forecast = CLOUDY;
  }
  else if ((dP_dt > 0.05) && (dP_dt < 0.25))
  {
    forecast = SUNNY;
  }
  else if ((dP_dt >(-0.05)) && (dP_dt < 0.05))
  {
    forecast = STABLE;
  }
  else
  {
    forecast = UNKNOWN;
  }

  // uncomment when debugging
  //Serial.print(F("Forecast at minute "));
  //Serial.print(minuteCount);
  //Serial.print(F(" dP/dt = "));
  //Serial.print(dP_dt);
  //Serial.print(F("kPa/h --> "));
  //Serial.println(weather[forecast]);

  return forecast;
}


void setup() {
  metric = getControllerConfig().isMetric;  // was getConfig().isMetric; before MySensors v2.1.1
  Wire.begin(); // Wire.begin(sda, scl)
  // use the 1.1 V internal reference
  #if defined(__AVR_ATmega2560__)
  analogReference(INTERNAL1V1);
  #else
  analogReference(INTERNAL);
  #endif
}

void presentation()  {
  // Send the sketch version information to the gateway and Controller
  sendSketchInfo("WeatherStation #20", "1.0");

  // Register sensors to gw (they will be created as child devices)
  present(BARO_CHILD, S_BARO);
  present(TEMP_CHILD, S_TEMP);
  present(HUM_CHILD, S_HUM);
  present(CHILD_ID_LIGHT, S_LIGHT_LEVEL);
}

// Loop
void loop() {

unsigned long currentMillis = millis();  

if(currentMillis - previousMillis > interval) {
    // save the last time sent the data
    previousMillis = currentMillis;


  analogReference(DEFAULT);
  wait(500);
   readLightLevel();   //Read Light

  analogReference(INTERNAL);
  wait(500);
  
  // need to read the NVM compensation parameters
  BME280.readCompensationParams();

  // Normal mode for regular automatic samples
  BME280.writeStandbyTime(tsb_0p5ms);         // tsb = 0.5ms
  BME280.writeFilterCoefficient(fc_16);       // IIR Filter coefficient 16
  BME280.writeOversamplingPressure(os16x);    // pressure x16
  BME280.writeOversamplingTemperature(os8x);  // temperature x8
  BME280.writeOversamplingHumidity(os8x);     // humidity x8
  
  BME280.writeMode(smNormal);

    // Just to be sure, wait until sensor is done mesuring  
    while (BME280.isMeasuring()) {
  }

  // Read out the data - must do this before calling the getxxxxx routines
  BME280.readMeasurements();

  float temperature = BME280.getTemperatureMostAccurate();                    // must get temp first
  float humidity = BME280.getHumidityMostAccurate();
  float pressure_local = BME280.getPressureMostAccurate();                    // Get pressure at current location
  float pressure = pressure_local/pow((1.0 - ( ALTITUDE / 44330.0 )), 5.255); // Adjust to sea level pressure using user altitude
  int forecast = sample(pressure);

  if (!metric) 
  {
    // Convert to fahrenheit
    temperature = temperature * 9.0 / 5.0 + 32.0;
  }

  Serial.println();
  Serial.print("Temperature = ");
  Serial.print(temperature);
  Serial.println(metric ? " °C" : " °F");
  Serial.print("Humidity = ");
  Serial.print(humidity);
  Serial.println(" %");
  Serial.print("Pressure = ");
  Serial.print(pressure);
  Serial.println(" hPa");
  Serial.print("Forecast = ");
  Serial.println(weather[forecast]);
  Serial.println();


    send(tempMsg.set(temperature, 1));
wait(50);
    send(humMsg.set(humidity, 1));
wait(50);
    send(pressureMsg.set(pressure, 2));
wait(50);
    send(forecastMsg.set(weather[forecast]));
wait(50);

}
}

void readLightLevel()      {
  Serial.println(analogRead(A0));  
  int lightLevel = (1023 - analogRead(LIGHT_SENSOR_ANALOG_PIN)) / 10.23; //To get a value ranging from 0 (dark) to 100 (bright).

#ifdef MY_DEBUG
  Serial.print("Light: "); Serial.println(lightLevel);
#endif
  send(light_Msg.set(lightLevel));

}

[RickyTerzis]

Hi...i am a new user here. I built a RFM69 gateway and a node.I decided to place the RFM69 node in a basement storage room. The room has been flooded a few times historically, so being able to monitor humidity in the room seems like a good idea.The room has thick brick walls, which the RFM69-433MHz radio is much more capable to handle than the nrf24. Still, I wanted to keep an eye on the signal strength. Because of this, I added code to the gateway to report RSSI from the node.

circuit card assembly