nightd
screen dimmer for android tv
keep your media playing while the screen goes dark
---
## what is this?
nightd is a tiny android tv app that blacks out your screen while keeping your media playing. perfect for:
- **falling asleep to music/podcasts** - screen goes dark, audio keeps playing
- **saving power on oled displays** - no burn-in, no wasted pixels
- **background audio** - cast audio without lighting up your room
## modes
| mode | what it does |
|------|-------------|
| **dim** | single overlay layer (~40% darker) |
| **black** | 5 stacked layers = pitch black (android limits overlay opacity to 80%, so we stack 'em) |
cycle order: `off → dim → black → off`
## installation
1. download the latest [nightd.apk](https://github.com/sudoxnym/nightd/releases/latest)
2. sideload via adb: `adb install nightd.apk`
3. grant "display over other apps" permission when prompted
## usage
### with key mapper (recommended)
use [key mapper](https://github.com/keymapperorg/KeyMapper) to bind nightd to remote buttons:
| action | intent |
|--------|--------|
| toggle | `com.sudox.nightd.TOGGLE` |
| dim mode | `com.sudox.nightd.DIM` |
| black mode | `com.sudox.nightd.BLACK` |
| turn off | `com.sudox.nightd.OFF` |
**package:** `com.sudox.nightd`
**service:** `com.sudox.nightd.NightdService`
example: bind "zoom in" to toggle, "zoom out" to off.
### with adb
```bash
# toggle (cycles through off → dim → black → off)
adb shell am startservice -a com.sudox.nightd.TOGGLE com.sudox.nightd/.NightdService
# specific modes
adb shell am startservice -a com.sudox.nightd.DIM com.sudox.nightd/.NightdService
adb shell am startservice -a com.sudox.nightd.BLACK com.sudox.nightd/.NightdService
adb shell am startservice -a com.sudox.nightd.OFF com.sudox.nightd/.NightdService
```
## how it works
android limits overlay opacity to 80% per layer. to achieve true black, nightd stacks 5 layers:
```
0.8 × 0.8 × 0.8 × 0.8 × 0.8 = 0.032 (96.8% blocked)
```
plus it sets screen brightness to 0 for good measure.
## permissions
- **SYSTEM_ALERT_WINDOW** - required to draw overlay
- **FOREGROUND_SERVICE** - keeps the overlay running
- **WRITE_SETTINGS** - adjusts screen brightness (optional, gracefully fails)
## building from source
```bash
# clone
git clone https://github.com/sudoxnym/nightd.git
cd nightd
# build (requires android ndk)
./gradlew assembleRelease
# or use the aapt/d8/apksigner toolchain directly
```
## license
MIT - do whatever you want with it.
---
built by sudoxnym for the sleep-deprived