EclipseClimateBridge

An Android app (bridge-app) that joins a Mitsubishi Eclipse Cross PHEV's Wi-Fi and starts/stops its climate control.

General idea is to have android phone with this app in the car always. You just call to the phone in a car and it will start predefined operation (heating, cooling or heating windshield).

You can trigger it from a button in the app or by calling the phone from an allowlisted number. It's pure Kotlin. There's no Gradle and no native code: bridge-app/build.ps1 runs the Android SDK command-line tools directly.

Other docs:

• RC4Solution.md: the app's architecture, first-run setup on the phone, and current status.
• MitsubishiEclipseCrossReverseEngineerWitifProtocol.md: the car's protocol.
• DEVELOPER-NOTES.md: test phone setup and debug/capture tooling.

Prerequisites

• Windows with PowerShell 5.1 or later.
• About 1 GB of free disk space for the toolchain.
• An Android 10+ phone (minSdk 29) with USB debugging enabled.
• The phone must already be paired with the car through the official Mitsubishi app (com.mitsubishi_motors.remote_ecp). The car only accepts commands from a Wi-Fi MAC address that the official app has registered. This app has no pairing logic of its own. See DEVELOPER-NOTES.md.

1. Install the toolchain (one time)

The build needs these exact versions:

Tool	Version	Why this version
JDK	17 (Temurin)	Runs kotlinc, d8 and apksigner
Android SDK platform	android-35	build.ps1 compiles against it (targetSdk 35)
Android SDK build-tools	35.0.1	Provides aapt2, d8, zipalign and apksigner
Kotlin compiler	2.0.x (2.0.21)	d8 from build-tools 35.0.1 can't read Kotlin 2.1+ metadata. Newer compilers still build, but d8 prints thousands of warnings.

build.ps1 looks for everything under %LOCALAPPDATA%\mitsubishi-android-build. Don't put the toolchain under %TEMP%, because Windows storage cleanup will eventually delete it.

Paste this into a PowerShell window. It downloads everything into the expected place:

$ErrorActionPreference = 'Stop'; $ProgressPreference = 'SilentlyContinue'
$root = "$env:LOCALAPPDATA\mitsubishi-android-build"
$dl = Join-Path $env:TEMP 'mitsubishi-android-build-dl'
New-Item -ItemType Directory -Force $root, $dl | Out-Null

# JDK 17 (latest Temurin 17 build)
Invoke-WebRequest 'https://api.adoptium.net/v3/binary/latest/17/ga/windows/x64/jdk/hotspot/normal/eclipse' -OutFile "$dl\jdk17.zip"
Expand-Archive "$dl\jdk17.zip" "$root\jdk17" -Force

# Kotlin compiler 2.0.21
Invoke-WebRequest 'https://github.com/JetBrains/kotlin/releases/download/v2.0.21/kotlin-compiler-2.0.21.zip' -OutFile "$dl\kotlinc.zip"
Expand-Archive "$dl\kotlinc.zip" "$root\kotlinc-download" -Force

# Android command-line tools; sdkmanager requires the cmdline-tools\latest layout
Invoke-WebRequest 'https://dl.google.com/android/repository/commandlinetools-win-15859902_latest.zip' -OutFile "$dl\cmdline.zip"
Expand-Archive "$dl\cmdline.zip" "$dl\cmdline" -Force
New-Item -ItemType Directory -Force "$root\sdk\cmdline-tools" | Out-Null
Move-Item "$dl\cmdline\cmdline-tools" "$root\sdk\cmdline-tools\latest"

# SDK packages. Licenses are accepted through cmd redirection, because piping "y" from
# PowerShell doesn't reliably reach sdkmanager and the install then silently does nothing.
$env:JAVA_HOME = (Get-ChildItem "$root\jdk17" -Directory | Select-Object -First 1).FullName
$sm = "$root\sdk\cmdline-tools\latest\bin\sdkmanager.bat"
Set-Content "$dl\yes.txt" -Value (@('y') * 30) -Encoding ascii
cmd /c "`"$sm`" --sdk_root=`"$root\sdk`" --licenses < `"$dl\yes.txt`" > nul 2>&1"
cmd /c "`"$sm`" --sdk_root=`"$root\sdk`" `"platforms;android-35`" `"build-tools;35.0.1`" `"platform-tools`" < `"$dl\yes.txt`""

Remove-Item -Recurse -Force $dl
Test-Path "$root\sdk\platforms\android-35\android.jar", "$root\sdk\build-tools\35.0.1\d8.bat", "$root\kotlinc-download\kotlinc\bin\kotlinc.bat"

The last line should print True three times. sdkmanager prints a deprecation warning ("Use Android CLI instead"); you can ignore it.

Check the JDK folder name. build.ps1 defaults to jdk17\jdk-17.0.20.1+1. If Adoptium gave you a newer 17.x build, the folder name will be different. In that case, run build.ps1 with -JavaHome set to the new folder, or change the default in build.ps1.

The toolchain is somewhere else? Pass its locations to build.ps1:

.\build.ps1 -SdkRoot <sdk> -JavaHome <jdk> -KotlinHome <kotlinc>

2. Build

cd bridge-app
.\build.ps1

build.ps1 runs these steps:

1. Compiles src/main/kotlin with kotlinc.
2. Links the manifest with aapt2.
3. Converts the classes to dex with d8.
4. Zip-aligns and signs the APK.

Output: bridge-app\build\bridge-app.apk. A successful build ends with Built: ....

A few things to know:

• Don't redirect the build's error output in Windows PowerShell 5.1. With redirects like 2>&1 or *>, PowerShell treats d8's warnings on stderr as a terminating error, and the build aborts. Run .\build.ps1 without redirects.
• Signing key. The first build creates a debug keystore at bridge-app\build\debug.keystore. build/ is gitignored, so each fresh clone or deleted build/ folder gets a new key. Android won't install an update over an APK signed with a different key (see below). To keep the same key, back up debug.keystore.

3. Install and run

adb is in %LOCALAPPDATA%\mitsubishi-android-build\sdk\platform-tools. Add that folder to PATH, or call adb by its full path.

adb install -r bridge-app\build\bridge-app.apk
adb shell am start -n fi.mitsukanny.phevbridge/.Rc4TestActivity

adb install -r may fail with INSTALL_FAILED_UPDATE_INCOMPATIBLE. That means the phone has a copy signed with a different debug key. Uninstall the old copy, then install again:

adb uninstall fi.mitsukanny.phevbridge

Uninstalling deletes the app's saved settings, so you'll need to enter them again.

On some phones adb install fails silently. If that happens, push the APK to the phone and install it there:

adb push bridge-app\build\bridge-app.apk /data/local/tmp/
adb shell pm install -r /data/local/tmp/bridge-app.apk

To finish setting up the app on the phone (car Wi-Fi credentials, allowlisted callers, permissions), follow RC4Solution.md → First-run setup.