flutter-pi

• Done. You can now run this app in release mode using flutter-pi --release /home/pi/flutter_gallery.

Building the App (old method, linux or windows)

rsync -a --info=progress2 ./build/flutterassets/ pi@raspberrypi:/home/pi/myappsflutterassets

scp -r ./build/flutterassets/ pi@raspberrypi:/home/pi/myappsflutterassets

git clone https://github.com/flutter/gallery.git flutter_gallery cd flutter_gallery git checkout d77920b4ced4a105ad35659fbe3958800d418fb9 flutter build bundle rsync -a ./build/flutterassets/ pi@raspberrypi:/home/pi/fluttergallery/

flutter build bundle

C:\flutter\bin\cache\dart-sdk\bin\dart.exe ^
      C:\flutter\bin\cache\dart-sdk\bin\snapshots\frontend_server.dart.snapshot ^
      --sdk-root C:\flutter\bin\cache\artifacts\engine\common\flutterpatchedsdk_product ^
      --target=flutter ^
      --aot ^
      --tfa ^
      -Ddart.vm.product=true ^
      --packages .darttool\packageconfig.json ^
      --output-dill build\kernel_snapshot.dill ^
      --verbose ^
      --depfile build\kernel_snapshot.d ^
      package:myappname/main.dart

gensnapshotlinuxx64release \
      --deterministic \
      --snapshot_kind=app-aot-elf \
      --elf=build/flutter_assets/app.so \
      --strip \
      --sim-use-hardfp \
      build/kernel_snapshot.dill

rsync -a --info=progress2 ./build/flutterassets/ pi@raspberrypi:/home/pi/myapp

scp -r ./build/flutterassets/ pi@raspberrypi:/home/pi/myapp

git clone https://github.com/flutter/gallery.git flutter_gallery
    git clone --depth 1 https://github.com/ardera/flutter-engine-binaries-for-arm.git engine-binaries
    cd flutter_gallery
    git checkout d77920b4ced4a105ad35659fbe3958800d418fb9
    flutter build bundle
    C:\flutter\bin\cache\dart-sdk\bin\dart.exe ^
      C:\flutter\bin\cache\dart-sdk\bin\snapshots\frontend_server.dart.snapshot ^
      --sdk-root C:\flutter\bin\cache\artifacts\engine\common\flutterpatchedsdk_product ^
      --target=flutter ^
      --aot ^
      --tfa ^
      -Ddart.vm.product=true ^
      --packages .darttool\packageconfig.json ^
      --output-dill build\kernel_snapshot.dill ^
      --verbose ^
      --depfile build\kernel_snapshot.d ^
      package:gallery/main.dart
    wsl
    ../engine-binaries/arm/gensnapshotlinuxx64release \
      --deterministic \
      --snapshot_kind=app-aot-elf \
      --elf=build/flutter_assets/app.so \
      --strip \
      --sim-use-hardfp \
      build/kernel_snapshot.dill
    rsync -a --info=progress2 ./build/flutterassets/ pi@raspberrypi:/home/pi/fluttergallery/
    exit

Running your App with flutter-pi

pi@hpi4:~ $ flutter-pi --help
flutter-pi - run flutter apps on your Raspberry Pi.
USAGE:   flutter-pi [options] <bundle path> [flutter engine options]
OPTIONS:   --release                  Run the app in release mode. The AOT snapshot                              of the app must be located inside the bundle directory.                              This also requires a libflutter_engine.so that was                              built with --runtime-mode=release.
--profile                  Run the app in profile mode. The AOT snapshot                              of the app must be located inside the bundle directory.                              This also requires a libflutter_engine.so that was                              built with --runtime-mode=profile.
--vulkan                   Use vulkan for rendering.
-o, --orientation <orientation>  Start the app in this orientation. Valid                              for <orientation> are: portraitup, landscapeleft,                              portraitdown, landscaperight.                              For more information about this orientation, see                              the flutter docs for the "DeviceOrientation"                              enum.                              Only one of the --orientation and --rotation                              options can be specified.
-r, --rotation <degrees>   Start the app with this rotation. This is just an                              alternative, more intuitive way to specify the                              startup orientation. The angle is in degrees and                              clock-wise.                              Valid values are 0, 90, 180 and 270.
-d, --dimensions "widthmm,heightmm" The width & height of your display in                              millimeters. Useful if your GPU doesn't provide                              valid physical dimensions for your display.                              The physical dimensions of your display are used                              to calculate the flutter device-pixel-ratio, which                              in turn basically "scales" the UI.
--pixelformat <format>     Selects the pixel format to use for the framebuffers.                              If this is not specified, a good pixel format will                              be selected automatically.                              Available pixel formats: RGB565, ARGB4444, XRGB4444, ARGB1555, XRGB1555, ARGB8888, XRGB8888, BGRA8888, BGRX8888, RGBA8888, RGBX8888,    --videomode widthxheight   --videomode widthxheight@hz  Uses an output videomode that satisfies the argument.                              If no hz value is given, the highest possible refreshrate                              will be used.
--dummy-display            Simulate a display. Useful for running apps                              without a display attached.   --dummy-display-size "width,height" The width & height of the dummy display                              in pixels.   --drm-fd <fd>              An opened and valid DRM file descriptor
-h, --help                 Show this help and exit.
EXAMPLES:   flutter-pi ~/helloworldapp   flutter-pi --release ~/helloworldapp   flutter-pi -o portraitup ./myapp   flutter-pi -r 90 ./my_app   flutter-pi -d "155, 86" ./my_app   flutter-pi --videomode 1920x1080 ./my_app   flutter-pi --videomode 1280x720@60 ./my_app
SEE ALSO:   Author:  Hannes Winkler, a.k.a ardera   Source:  https://github.com/ardera/flutter-pi   License: MIT
For instructions on how to build an asset bundle or an AOT snapshot     of your app, please see the linked github repository.   For a list of options you can pass to the flutter engine, look here:     https://github.com/flutter/engine/blob/main/shell/common/switches.h

<asset bundle path> is the path of the flutter asset bundle directory (i.e. the directory containing kernel_blob.bin) of the flutter app you're trying to run.

[flutter engine options...] will be passed as commandline arguments to the flutter engine. You can find a list of commandline options for the flutter engine Here.

gstreamer video player

To use the gstreamer video player, just rebuild flutter-pi (delete your build folder and reconfigure) and make sure the necessary gstreamer packages are installed. (See dependencies)

And then, just use the stuff in the official video_player package. (VideoPlayer, VideoPlayerController, etc, there's nothing specific you need to do on the dart-side)

audioplayers

• As flutter-pi is intended for use on constrained systems like raspberry pi, you should avoid creating multiple temporary instances and instead prefer to use one global instance of AudioPlayer. There is limit you can easily hit if you're going to spam multiple instances of AudioPlayer
• Plugin was tested to work with ALSA and pulseaudio might prevent the plugin from playing audio correctly:

• Finally, if you want to verify your audio setup is good, you can use gst-launch command to invoke playbin on audio file directly.

📊 Performance

Graphics Performance

Touchscreen Latency

This is why I created my own (userspace) touchscreen driver, for improved latency & polling rate. See this repo for details. The driver is very easy to use and the difference is noticeable, flutter apps look and feel a lot better with this driver.

📦 Useful Dart Packages

| Package | Category | Author | Description | | - | - | - | - | | flutterpitool (package) (repo) | 🔧 tooling | Hannes Winkler (me) | Tool to make developing & distributing apps for flutter-pi easier. | | fluttergpiod (package) (repo) | 🖨 peripherals | Hannes Winkler | GPIO control support for dart/flutter, uses kernel interfaces directly for more performance. | | linuxserial (package) (repo) | 🖨 peripherals | Hannes Winkler | Serial Port support for dart/flutter, uses kernel interfaces directly for more performance. | | linuxspidev (package) (repo) | 🖨 peripherals | Hannes Winkler | SPI bus support for dart/flutter, uses kernel interfaces directly for more performance. | | dartperiphery (package) (repo) | 🖨 peripherals | Peter Sauer | All-in-one package GPIO, I2C, SPI, Serial, PWM, Led, MMIO support using c-periphery. | | flutterpigstreamervideoplayer (package) (repo) | ⏯️ multimedia | Hannes Winkler | Official video player implementation for flutter-pi. See GStreamer video player section above. | | charsetconverter (package) (repo) | 🗚 encoding | Bartosz Wiśniewski | Encode and decode charsets using platform built-in converter. | | sentryflutter (package) (repo)| 📊 Monitoring | sentry.io | See https://github.com/ardera/flutter-pi/wiki/Sentry-Support for instructions. |