OpenDew

what is it

a collection of simple shellscripts to

collect data from external wireless temperature/humidity sensors
calculate dewpoint temperature
turn on/off a fan (through a smartplug)

why

when last did you ventilate the cellar?

why openwrt / rtl_433 / shellscript ?

the choise of the components was defined by availability in my stuff box. :)

todo

add support for wired sensors (i2c/onewire)?

hardware

an OpenWRT compatible router (e.g. some from TP-Link) with USB port
a Realtek RTL2832 based DVB dongle (https://osmocom.org/projects/rtl-sdr/wiki)
some temperature/humidity sensors (433/868Mhz)

software

(os) http://openwrt.org
(sdr) https://github.com/merbanan/rtl_433 /
(broker) https://mosquitto.org

mqttreader

reads rtl_433 sensor data from 'rtl_433/{hostname}/events' (rtl_433 default topic)

{
  "time": "2024-04-07 16:27:27.095538",
  "model": "Nexus-TH",
  "id": 231,
  "channel": 1,
  "battery_ok": 1,
  "temperature_C": 27.4,
  "humidity": 35
}

{
  "time": "2024-04-07 16:27:27.095538",
  "model": "Bresser-3CH",
  "id": 116,
  "channel": 3,
  "battery_ok": 1,
  "temperature_C": 15.5,
  "humidity": 63,
  "mic": "CHECKSUM"
}

and publishes to 'app/dewpoint/sensors/in'

{ "name": "id1-231", "temperature_C": 27.4, "humidity": 35 }

{ "name": "id3-116", "temperature_C": 15.5, "humidity": 63 }

sensormaster

reads sensor data from 'app/dewpoint/sensor/in'

{ "name": "id1-231", "temperature_C": 27.4, "humidity": 35 }

{ "name": "id3-116", "temperature_C": 15.5, "humidity": 63 }

uses a configuration to map from external sensor ids to internal names

[
    {
        "name":"id3-116",
        "id":"keller1"
    },  
    {
        "name":"id1-231",
        "id":"aussen1stock"
    }
]

calculate dewpoint according to temperature / humidity and publishes to 'app/dewpoint/in'

{
    "ts":"2024-04-07_16:27:29+CEST", 
    "name":"aussen1stock",  
    "temperature_C":27.4, 
    "humidity":35,
    "dew":10.5808
}

{
    "ts":"2024-04-07_16:27:30+CEST",
    "name":"keller1",
    "temperature_C":15.5,
    "humidity":63,
    "dew":8.48191
}

dewcalculator

read from 'app/dewpoint/in'

{
    "ts":"2024-04-07_16:27:29+CEST", 
    "name":"aussen1stock",  
    "temperature_C":27.4, 
    "humidity":35,
    "dew":10.5808
}

{
    "ts":"2024-04-07_16:27:30+CEST",
    "name":"keller1",
    "temperature_C":15.5,
    "humidity":63,
    "dew":8.48191
}

has a mapping where multiple indoor/outdoor sensors can be configured.

{
    "insensors": [
        "keller1"
    ],
    "outsensors": [
        "aussen1stock"
    ]
}

when data from every sensor is available
average outdoor/indoor temperature, humidity and dewpoint are calculated.

publishes to 'app/dewpoint/out'

{
  "ts": "2024-04-07_16:27:32+CEST",
  "dew_avg": {
    "delta": -2.09889,
    "indoor": 8.48191,
    "outdoor": 10.5808
  },
  "temperature_avg": {
    "indoor": 15.5,
    "outdoor": 27.4
  },
  "humidity_avg": {
    "indoor": 63,
    "outdoor": 35
  },
  "sensors": {
    "indoor": [
      {
        "ts": "2024-04-07_16:26:10+CEST",
        "name": "keller1",
        "temperature_C": 15.5,
        "humidity": 63,
        "dew": 8.48191
      }
    ],
    "outdoor": [
      {
        "ts": "2024-04-07_16:27:29+CEST",
        "name": "aussen1stock",
        "temperature_C": 27.4,
        "humidity": 35,
        "dew": 10.5808
      }
    ]
  },
  "app": {
    "dew_diff_min": 1.0,
    "dew_diff_max": 2.3,
    "room_temperature_min": 10.0
  }
}

dewapp

reads from 'app/dewpoint/out'

{
  "ts": "2024-04-07_16:27:32+CEST",
  "dew_avg": {
    "delta": -2.09889,
    "indoor": 8.48191,
    "outdoor": 10.5808
  },
  "temperature_avg": {
    "indoor": 15.5,
    "outdoor": 27.4
  },
  "humidity_avg": {
    "indoor": 63,
    "outdoor": 35
  },
  "sensors": {
    "indoor": [
      {
        "ts": "2024-04-07_16:26:10+CEST",
        "name": "keller1",
        "temperature_C": 15.5,
        "humidity": 63,
        "dew": 8.48191
      }
    ],
    "outdoor": [
      {
        "ts": "2024-04-07_16:27:29+CEST",
        "name": "aussen1stock",
        "temperature_C": 27.4,
        "humidity": 35,
        "dew": 10.5808
      }
    ]
  },
  "app": {
    "dew_diff_min": 1.0,
    "dew_diff_max": 2.3,
    "room_temperature_min": 10.0
  }
}

calculates if fan should be turned on/off according temperature / dewpoint data.

publishes to 'app/dewpoint/control'

{
    "ts":"2024-04-07_16:27:37+CEST",
    "type":"control",
    "fan":0
}

dewcontrol

reads from 'app/dewpoint/control'

{
    "ts":"2024-04-07_16:27:37+CEST",
    "type":"control",
    "fan":0
}

read user provided functions from '/etc/opendew/custom.sh'

# custom user actions can be executed here

custom_fanon() {
	logger "custom fan on :)"
    curl http://espplug.fritz.box/cm?cmnd=Power%20on
}

custom_fanoff() {
	logger "custom fan off :)"
    curl http://espplug.fritz.box/cm?cmnd=Power%20off
}

custom_status_on() {
    logger "custom status changed to on"
}

custom_status_off() {
    logger "custom status changed to off"
}

executes custom_fanoff() or custom_fanon() functions (if defined).

configuration

configfile '/etc/opendew/opendew.cfg'


MQTTHOST="localhost"
MQTTPORT="1883"
MQTTUSER=""
MQTTPASS=""

MQTTTOPICBASE="app/dewpoint"

MQTTREADER_INTOPIC="rtl_433/+/events"

DEW_DIFF_MAX=2.3
DEW_DIFF_MIN=1.0 
ROOM_TEMP_MIN=10.0

SENSORMASTERCONFIG='[{"name":"id3-116","id":"keller1"},{"name":"id1-231","id":"aussen1stock"}]'

SENSORCONFIG='{"insensors":["keller1"],"outsensors":["aussen1stock"]}'

sensor mapping (rtl_433 to internal)

SENSORMASTERCONFIG='[{"name":"id3-116","id":"keller1"},{"name":"id1-231","id":"aussen1stock"}]'

In a first step, the sensor data must be converted from the rtl_433 proprietary format into the application's own data format.

// rtl_433 specific
{
  "time": "2024-04-07 16:27:27.095538",
  "model": "Bresser-3CH",
  "id": 116,
  "channel": 3,
  "battery_ok": 1,
  "temperature_C": 15.5,
  "humidity": 63,
  "mic": "CHECKSUM"
}

// dew app specific
{ 
  "name": "id3-116", 
  "temperature_C": 15.5, 
  "humidity": 63 
}

During this process, a unique ID is also assigned to each sensor, which is then used internally. In the event of a sensor replacement (e.g., due to a defect), only the mapping to the internal name/ID needs to be changed.

The ID generation follows the following pattern:

id{rtl_433.channel}-{rtl_433.id}

e.g.

id:116, channel=3 -> 'id3-116'

sensor mapping (internal to in/outsensor)

SENSORCONFIG='{"insensors":["keller1","keller2","keller3"],"outsensors":["aussen1stock","aussenterrasse"]}'

Indoor and outdoor sensors can be defined as 1 to n sensors each. The respective value (temperature, humidity, and dew point) is determined as the average across all configured sensors for indoor/outdoor use.

faq

will it also run on a 'real' linux system?

Probably.
The shellscripts should run on any linux system, but startup scripts for initd / systemd are necessary.

is there a UI available?

No.

how to display data?

Use your favorite home automation system.
For example: FHEM

womoak75 / opendew Goto Github PK

opendew's Introduction