miluka Splitgrade Controller

Android companion app for the open-source splitgrade enlarger LED head: connects over Bluetooth LE, sets hard/soft exposure times, and runs exposures — no light sensor required. On-device name: miluka Splitgrade Controller.

Pairs with the shared head firmware: darkroom-enlarger-head (Seeed XIAO ESP32-S3 + SK6812RGBW panel).

License: MIT — Copyright © 2026 Dragan Bojovic.

What this is

Platform	Android (minSdk 26), phones and tablets
Link	BLE GATT (JSON commands)
Role	Budget-tier controller — phone you already own
Package	com.dragan.darkroom_timer

This is the cheap half of the two-tier design: the same enlarger head also speaks ESP-NOW for a SenseCAP primary-tier controller with sensors (splitgrade-controller-sensecap, when published). The head firmware is shared; only the remote changes.

Beta scope

For: darkroom hobbyists with an Android phone/tablet and a flashed enlarger-head board.

Includes: BLE scan/connect, focus / expose UI, hard & soft times, hidden LED config (pixel count + GPIO), wake-lock during exposure.

Not this repo: ESP32 firmware, SenseCAP UI, panel Gerbers, Play Store release signing. Emulator BLE is unreliable — use a real device.

Requirements

• Flutter SDK (stable)
• Android SDK (minSdk 26)
• Physical Android device with BLE
• Flashed darkroom-enlarger-head nearby and powered

Run / build

flutter pub get
flutter run                          # connected device
flutter build apk --release          # APK under build/app/outputs/
flutter test

Open this folder in VS Code with the Flutter extension if you prefer the IDE buttons — same commands underneath.

Project layout

Path	Role
lib/main.dart	App entry
lib/ble/ble_service.dart	BLE + JSON protocol (must match firmware ble_server)
lib/ble/ble_constants.dart	Service / characteristic UUIDs
lib/screens/home_screen.dart	Focus / Expose UI
lib/screens/settings_sheet.dart	LED pin / pixel-count config
lib/widgets/	Exposure button, time display, orientation gate
lib/models/device_config.dart	LED config model

Status

Verified on real hardware (phones and a tablet). Needs the enlarger-head firmware advertising as DarkroomTimer over BLE.

Sibling project

• Head firmware: https://github.com/Draganito/darkroom-enlarger-head