MuhPortal

An Android application built with Kotlin and Jetpack Compose to monitor and control a smart home via MQTT over WebSockets.

Features

• Portal Control: Monitor and toggle garage, garage door, and house door states in real time.
• Wake-on-LAN: Wake and shut down networked machines; shows live online/offline status.
• Home Automation (HA tab):
  • Temperature and humidity sensors
  • Solar PV power and daily production
  • Energy meter (consumption, import, export)
  • Heater (Brenner) and zone (Kommer) switch control
  • Alarm system: arm/disarm with live alert feed
• Connection Management: Automatic reconnection, visual status bar (green/yellow/red).
• Local Cache: Last-known state persisted to SharedPreferences, restored on launch.
• Configurable: All MQTT topics, device IDs, and sensor JSON keys editable in-app settings.
• Dark mode & high-contrast (black/white) accessibility mode.

Screenshots

Technical Specifications

Language	Kotlin
UI	Jetpack Compose / Material3
Build	Gradle (Kotlin DSL)
MQTT library	Eclipse Paho MQTT Client 1.2.5
Protocol	MQTT over WebSockets
Min SDK	28 (Android 9)
Target SDK	35 (Android 15)

MQTT Architecture

Portal tab

Direction	Topic	Payload
Subscribe	muh/portal/+/json	{"state":0|1, "ts":"..."}
Publish	muh/portal/RLY/cmnd	G_T, GD_O, GD_U, GD_L, HD_O, HD_U, HD_L

Portal keys: G Garage · GD Garage Door · GDL Garage Door Lock · HD House Door · HDL House Door Lock

WoL tab

Direction	Topic	Payload
Subscribe	muh/pc/+	{"name":"…","ip":"…","mac":"…","alive":true}
Publish	muh/wol	{"mac":"…"}
Publish	muh/poweroff	{"mac":"…"}

HA tab

Direction	Topic	Payload
Subscribe	muh/sensors/#	JSON with temp/humidity fields
Subscribe	muh/wst/data/+	JSON weather station data
Subscribe	muh/pv/+/json	{"data":{"p1":…,"p2":…,"e1":…,"e2":…}}
Subscribe	tasmota/tele/+/STATE	Tasmota state JSON
Subscribe	tasmota/tele/+/SENSOR	Tasmota sensor/energy JSON
Subscribe	tasmota/stat/+/RESULT	Tasmota command result
Publish	tasmota/cmnd/{id}/POWER	0 or 1

Alarm System

Direction	Topic	QoS	Retain	Payload
Subscribe	muh/alarm/state	1	yes	ARM_AWAY | ARM_HOME | DISARM
Subscribe	muh/alarm/alert	1	no	{"device":"…","label":"…","alarmState":"…","time":"HH:mm:ss","ts":"…"}
Publish	muh/alarm/set	1	no	ARM_AWAY | ARM_HOME | DISARM

Installation

On a physical device

1. Enable Developer Options and USB Debugging on the device.
2. Connect via USB, then:

   ./gradlew assembleDebug
   adb install app/build/outputs/apk/debug/app-debug.apk

On a Linux emulator

Prerequisites: Android Studio installed (includes the emulator and sdkmanager).

1. Create an AVD via Android Studio → Device Manager → Create Virtual Device, or from the command line:

   # List available system images
   sdkmanager --list | grep "system-images;android-35"
   
   # Download a system image (x86_64 for speed)
   sdkmanager "system-images;android-35;google_apis;x86_64"
   
   # Create the AVD
   avdmanager create avd -n MuhPortal -k "system-images;android-35;google_apis;x86_64" --device "pixel_6"

2. Start the emulator:

   # The emulator binary lives in $ANDROID_HOME/emulator/
   emulator -avd MuhPortal -no-snapshot-load &

   If KVM is not available, add -accel off (much slower):

   emulator -avd MuhPortal -no-snapshot-load -accel off &

   Enable KVM on Linux for full speed:

   sudo apt install qemu-kvm
   sudo usermod -aG kvm $USER   # log out and back in after this

3. Build and install:

   ./gradlew assembleDebug
   adb install app/build/outputs/apk/debug/app-debug.apk

4. MQTT broker reachability: the emulator's 10.0.2.2 routes to the host's 127.0.0.1. If your broker runs on the host, set the Server URI in app settings to ws://10.0.2.2:1884. For a broker on another LAN host, use its normal IP.

Building a release APK

Set the keystore environment variables, then:

export KEYSTORE_PATH=/path/to/release.keystore
export KEYSTORE_PASSWORD=...
export KEY_ALIAS=...
export KEY_PASSWORD=...

./gradlew assembleRelease
# Output: app/build/outputs/apk/release/app-release.apk