How to develop an app

2025-08-11T17:02:05Z

Sgielen: /* Add your own app */

== How to develop an app for the badge ==

''This is living documentation, check often for updates''

WARNING: the documentation might be out of date. But it might be better than no documentation.
We try to update as soon as possible.

For now, the documentation is focused on Linux. MacOS might work, for Windows, you probably need WSL.

=== Clone the firmware repo ===

Also read the [https://gitlab.com/why2025/team-badge/firmware README].

git clone https://gitlab.com/why2025/team-badge/firmware.git

=== Install ESP-IDF ===

Follow instructions here

[https://docs.espressif.com/projects/esp-idf/en/stable/esp32/get-started/index.html#installation ESP32 installation]

At the point where you run <code>install.sh</code>, give <code>esp32p4</code> as argument.

./install.sh esp32p4

If you type

idf.py --version

you should get the version number. If not, you might need to activate it.

. ~/esp/esp-idf/export.sh

If you're using NixOS with [https://github.com/mirrexagon/nixpkgs-esp-dev nixpkgs-esp-dev],
make sure to run <code>export ESP_IDF_VERSION=5.5</code> after calling <code>nix develop</code>.

=== Build and install ===

First connect to the USB-C connector at the upper side of the badge.

Go to the firmware directory of the cloned repository and build and install the firmware

idf.py build flash monitor

This takes quite some time since the whole firmware is being build and flashed.
For updating only an app, see mpydaemon below.

=== Add your own app ===

Create a new directory in <code>sdk_apps/</code> and copy <code>sdk_apps/hello/main.c</code> to it. Also copy <code>sdk_apps/hello/manifest.json</code> as well and update it, and create an empty <code>storage_skel</code> directory.

Adjust <code>flash_storage/skel/init.toml</code> and add your app.

Adjust <code>sdk_apps/CMakeLists.txt</code> and add your app.

Make changes, then build and flash again with <code>idf.py</code>. Look at other apps in <code>sdk_apps</code> for examples.

See <code>sdk_apps/sdl_test/sdl_test.c</code> for an example on how to use SDL3 (specifically graphics).

After changing <code>init.toml</code>, you might want to delete a directory:

rm -rf build/storage_staging/

=== Test locally ===

To improve development speed, you want to develop and test locally.

The badge uses SDL3, which is a OS independent hardware layer that can be used on your computer.

Install SDL3:

https://github.com/libsdl-org/SDL/blob/main/INSTALL.md

On Linux, you might need to install the packages described here: [https://wiki.libsdl.org/SDL3/README-linux SDL Wiki Linux]

After this, you might want to run

sudo ldconfig

Now go inside your app directory and you can compile your app for your OS:

gcc myapp.c -o myapp -I /usr/local/include/SDL3 -L/usr/local/lib -lSDL3

(adjust paths as needed)

Now you can run the app locally:

./myapp

=== Use mpydaemon ===

Use mpydaemon to update only your app. You need an SD card installed.

See [https://gitlab.com/why2025/team-badge/micropython/-/tree/master/mpydaemon mpydeamon]

=== Share ===

If you made an app that you want to share, upload it to

[https://badge.why2025.org/ BadgeHub]

User:Sgielen

2025-08-01T23:30:34Z

Sgielen:

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User:Sgielen

2025-05-26T18:11:35Z

Sgielen:

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User:Sgielen

2025-05-26T18:10:28Z

Sgielen: create user page

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WHY2025 wiki - User contributions [en]

How to develop an app

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