Domotiocz + Rain gauge

[flopp]

@TheoL RAINRATE is implemented according to this page https://github.com/domoticz/domoticz/blob/master/hardware/MySensorsBase.cpp but I don't know how to use it. I know that DZ doesn't work with this example https://www.mysensors.org/build/rain

[flopp]

I have adjust my bucked to tip every ~0.25mm and calibrated it ofcourse

[AWI]

Domoticz just recently changed the method of rain rate calculation. It does not interpret rainrate values sent by sensors but calculates this by the total value coming in.

[TheoL]

@AWI Thank you again. I already had a gut feeling this would be the case. I'll strip out the rain rate code from the sketch.

[BulldogLowell]

@TheoL

Great to see this project continuing to grow legs!

[Hilltan]

This post is deleted!

[flopp]

@sundberg84 said:

I just wanted to celebrate 1 year for my Rainsensor on batteries, reporting every hour (or less when it rains). Still going strong and 81% battery left! Except for some range issues in the beginning you can see its working as it should:

WOW, nice. Would it be possible to see your Battery graph, if you have one?
I am send data every 2h or often when it rains but my battery is draining much quicker than yours. Maybe I will get 1 year out of it, so I am happy anyway.
But I am interested in your graph if the voltage is going down quicker in the beginning.

[Hilltan]

Maybe a stupid question, but it is possible to replace the SI7021 sensor with a DHT-22 sensor (the code has to be changed offsourse)? And get everything to work with ThresholdUtil? I have all parts, but not the SI7021 sensor to build the rain gauge.

[TheoL]

@Hilltan That should really be easy. I've created the threshold util especially for this. You only have to replace the si7021 init part with the DHT22 init part and replace the reading part of the si7021 in the threshold util callback with reading the DHT22 part. Then you're done.

Just give it a try yourself. It's really not that hard.

There's however a reason why I use the si7021 instead of the DHT's. I've had serious troubles with the DHT sensors. Some of them wouldn't report the values to the gateway for a week. After the that the node spontaneously started reporting again. I have a sense bender running for more than a half year flawlessly. So in my opinion the si7021 is superior to the DHT.

[AWI]

@Hilltan Like @TheoL mentioned, try to avoid the DHT22, especially for battery powered operation. The DHT-22 is (apart from other disadvantages) specified for a working voltage from 3.3-6V. And tend to get unstable at low voltages.

[hek]

Hmm.. @AWI, @TheoL maybe we should replace DHT example on the main site for something more modern?

[TheoL]

@hek That sounds like a good idea. Should we also indicate that the SI7021 is a sensor for more experienced users? Because you need to solder wires or headers to it.

[hek]

Yes, But they exist in breakout board variants. So it shouldn't be much more effort than connecting a DHT module.

[AWI]

@hek @TheoL let's join forces. Dht21 or si7021 share the same code and both available on a board with level converter. And a sketch wit Bme280 (with pressure)
Making a drawing (kicad) is not my thing. The rest ok

[hek]

Yep, note that the BMP180/BMP085 is described in the https://www.mysensors.org/build/pressure example. BME280 might be a better choice nowadays perhaps.

[TheoL]

@AWI Would love to join forces with you my friend. I can make a Fritzing ;-)

[AWI]

@TheoL deal:thumbsup:

[TheoL]

@hek The BME280 is very interesting. But for most of my temp sensors I'm only interested in Temp and Humidity. At the moment I have only one Pressure sensor.

[Hilltan]

@TheoL

How will the numbers affect the Thresholds reading and reporting of the sensor?

registerThresholdedSensor( CHILD_ID_TEMP, 1, TEMPERATURE_SENSOR, 0.5, 30, 20 );

0.5 //What will this do?
30 //What will this do?
20 //That one I assume is how often the value will be sent to the gateway?

void updatedTHSensorValue( uint8_t child_id, uint8_t sensor_id, ThreshHoldedSensorType sensor_type, float value ) {
switch ( child_id ) {
case CHILD_ID_TEMP:
Serial.print( "Sending temp " );
Serial.println( value, 1 ); //What will this do?
send( msgTemp.set( value, 1 ) ); //What will this do?
break;

I don’t have the SI7021 sensor yet so therefore my questions

And a problem with the DHT sensor is correct me if I am wrong, is that the DHT sensor does not like to be “read” to often. How will I do this? Or maybe the answer to my question is in the registerThresholdedSensor code ;).

[TheoL]

@Hilltan I assume that you've downloaded my ThresholdUtil library from my github.

The three values are:

• theshHold: The value of threshold is indicates how much the new value needs to differ from the last send value before it triggers a resend.
• readingInterval: The amount of seconds the library waits before it request a new value for this sensor
• forcedTransmissionInterval: The amount of measurements without retransmissions, before a retransmission is triggered. In other words if the values of a sensor don't extend the threshold, a retransmissionis triggered of this given amount of readings.

I just checked my github and there's a none MySensors example handling a DHT22 and a Lux sensors. You can find it here

I initialize the threshold util as follows

#include "ThresholdUtil.h"

#include "DHT.h"

DHT dht;


#define DHT 0

#define CHILD_ID_TEMP 0
#define CHILD_ID_HUMIDITY 1
#define CHILD_ID_LIGHT_SENSOR 2
#define DHT22_PIN 14

void setup() {
  Serial.begin( 115200 );

  registerThresholdedSensor( CHILD_ID_TEMP, DHT, TEMPERATURE_SENSOR, 0.5, 30, 20 ); // every 30 seconds report at least every 10 minutes
  registerThresholdedSensor( CHILD_ID_HUMIDITY, DHT, HUMIDTY_SENSOR, 1.0, 60, 10 ); // every 60 seconds

  dht.setup( DHT22_PIN ); // data pin 2

  delay( dht.getMinimumSamplingPeriod() );

  checkThresholdedSensors( checkThrsedSensor, reportSensorValue ); // Necessary call for intializing ThresholdUtil
}

This means that I read the temp value every 30 seconds and report the temperature at least every 10 minutes or if the temperature lowers a half degree. But it would be better to change the half degree into 1 degree.
The humidity gets read every minute and will report at least every 10 minutes as well. Or when the humidity drops or raises 1 %. But I think I would use 2 percent in production.

To make sure the DHT is not being read to often. I remember the humidity when I read the temperature from the DHT. So when the ThresholdUtil requests the humidity state I return the humidity we last read.

float dhtHumidity; 

void checkThrsedSensor( uint8_t aSensorId, ThreshHoldedSensorType aType, float *value ) {
  if ( aSensorId == DHT  ) {
    if ( aType == TEMPERATURE_SENSOR ) {
      dhtHumidity = dht.getHumidity();
      *value = dht.getTemperature();
    }
    else {
      *value = dhtHumidity;
    }
  }
  if ( aSensorId == LUX_SENSOR && aType == LIGHTLEVEL_SENSOR ) {
    *value = random( 30, 40 ); // not sure why but I apparently just fake the light level sensor
  }
}

The remainder of the sketch contains a callback handler for reporting the sensor values e.g. to MySensors. But I've noticed that I need to update that example on github

void reportSensorValue( uint8_t child_id, uint8_t sensor_id, ThreshHoldedSensorType sensor_type, float value ) {
  Serial.print( millis() ); Serial.print( ": new sensor value " );
 Serial.print( value ); 
Serial.print( child_id == CHILD_ID_TEMP ? " C" : " %" );
 Serial.print( " for child " );
 Serial.println( child_id == CHILD_ID_TEMP ? "temp" : ( child_id == CHILD_ID_HUMIDITY ? "hum" : "light" ) );
}

And in the loop we continuously call the checkThresholdedSensors method, that well handle all the timing part for you. So that the check only gets called when needed and the report only when a sensor value needs to be reported.

void loop() {
  checkThresholdedSensors( checkThrsedSensor, reportSensorValue );
}

Hope this helps you a bit. I'm currently to occupied to update the sketch for you.