bathcontrol example

Author: mathertel

examples/bathcontrol.md

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+# Bathroom Climate control
+
+--
+
+This example demonstrates how to implement an IoT device for controlling a bathroom or cellar fan with the help of the HomeDing library.
+
+## Situation
+
+In many residential buildings, there are rooms where water usage leads to increased air humidity.
+Also after using the toilet you may want some fresh air in the room.
+
+High humidity levels can cause various problems, including mold growth, unpleasant odors, and damage to walls or
+furniture.  Extended exposure to high humidity can also adversely affect health and comfort.
+
+To reduce humidity, you can either open a window (if available) or use a fan to exhaust the moist air.  This example
+focuses on controlling such a fan using an IoT device with built-in rules that apply to this situation.
+
+## Rules for the fan
+
+In conventional installations, bathroom fans are typically controlled by the light switch, continuing to run for a
+preset time after the light is turned off.  This approach can be inefficient when using the room without generating
+excess humidity.
+
+Some more modern devices also have sensors for humidity and adjust their activity when humidity reaches a threshold.
+
+This IoT device offers a smarter solution by combining two sensors and a pushbutton and can implement some more smart rules that can be adjusted
+using the remote web interface. This example uses this approach and provides the following features:
+
+* A light sensor is capturing the light situation. The light switch is not used.
+  Instead a simple light sensor is used to trigger fan activity. No need to capture a signal from a high voltage line.
+* A Humidity sensor is capturing the light situation.
+*
+* The fan doesn't start when the light is switched on for a few seconds only.
+* The fan will be started for a few minutes after the light has been switched off.
+* When the humidity sensor signals a humidity higher than 80 % the fan will start.
+* When the humidity has fallen under 60 % the fan will be switched off.
+* When pressing the push button the fan will be activated for 60 seconds per push.
+* When long pressing the push button the device will go into off mode.
+* When long pressing the push button again the device will start again in normal mode.
+
+You can change all the threshold and time values in the configuration of the device
+and adapt or extend the configuration to your special needs.
+
+There are some rules implemented that cover the above ideas that can be switched on/off using the web user interface.
+They are running independently and the fan will be activated whenever one of the triggers wants it.
+
+Analog in with LDR -> [Reference Element] onHigh -> Start Light [Timer Element]
+Analog in with LDR -> [Reference Element] onLow -> Stop Light [Timer Element]
+
+When the light is detected only for a short time this timer will not reach the end before stopped and onEnd Event
+will not be triggered.
+
+Light Timer onEnd -> Start Fan [Timer Element]
+
+
+The Light Trigger part of the configuration
+
+
+[Reference Element]: /elements/reference.md
+[Timer Element]: /elements/timer.md
+
+
+``` json
+{
+  "digitalout": {
+    "relay": {
+      "title": "relay",
+      "pin": "3"
+    },
+    "led": {
+      "title": "led",
+      "pin": "8",
+      "invert": "1"
+    }
+  },
+  "timer": {
+    "led": {
+      "mode": "timer",
+      "restart": "1",
+      "waittime": "8s",
+      "pulsetime": "20s",
+      "cycletime": "80s",
+      "onHigh": "device/0?log=onHigh",
+      "onLow": "device/0?log=onLow",
+      "onValue": "digitalout/relay?value=$v",
+      "onEnd": "device/0?log=onEnd",
+      "title": "timer/led"
+    }
+  },
+  "bh1750": {
+    "lux": {
+      "title": "light",
+      "readtime": "2s"
+    }
+  }
+}
+```
+