WHY2025 wiki - User contributions [en]

How to develop an app

2025-08-16T19:44:39Z

Felixwebercouk: Clarify goal of local building

== 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WARNING: the documentation might be out of date.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.

Type CTRL-] to end the monitor.

=== 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 build flash monitor</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/

=== Build locally ===

To build locally, call <code>get_idf</code> after installing ESP-IDF (or have another <code>riscv32-esp-elf-gcc</code> command available) and run-

<pre>
riscv32-esp-elf-gcc \
-O2 -flto -fPIC -fdata-sections -ffunction-sections \
-fno-builtin -fno-builtin-function -fno-common -fno-jump-tables \
-fno-tree-switch-conversion -fstrict-volatile-bitfields -fvisibility=hidden \
-g3 -mabi=ilp32f -march=rv32imafc_zicsr_zifencei \
-nostartfiles -nostdlib -shared \
-Wl,--strip-debug -Wl,--gc-sections -e main \
-isystem build/sdk_staging/include \
-o build/app_elfs/[your_app].elf \
sdk_apps/[your_app]/main.c
</pre>

(Replace [your_app].)

This mirrors the flags used in CMakeLists.txt and will build an .elf to run on the WHY2025 badge, possibly to be copied to the badge with [https://wiki.why2025.org/index.php?title=How_to_develop_an_app#Use_mpydaemon mpydaemon/mpytool.sh].

=== 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]

How to develop an app

2025-08-16T19:40:44Z

Felixwebercouk: Add local machine .elf building instructions

== 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.

Type CTRL-] to end the monitor.

=== 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 build flash monitor</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/

=== Build locally ===

To build locally, call <code>get_idf</code> after installing ESP-IDF (or have another <code>riscv32-esp-elf-gcc</code> command available) and run-

<pre>
riscv32-esp-elf-gcc \
-O2 -flto -fPIC -fdata-sections -ffunction-sections \
-fno-builtin -fno-builtin-function -fno-common -fno-jump-tables \
-fno-tree-switch-conversion -fstrict-volatile-bitfields -fvisibility=hidden \
-g3 -mabi=ilp32f -march=rv32imafc_zicsr_zifencei \
-nostartfiles -nostdlib -shared \
-Wl,--strip-debug -Wl,--gc-sections -e main \
-isystem build/sdk_staging/include \
-o build/app_elfs/[your_app].elf \
sdk_apps/[your_app]/main.c
</pre>

(Replace [your_app].)

This mirrors the flags used in CMakeLists.txt.

=== 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:Felixwebercouk

2025-08-05T10:48:30Z

Felixwebercouk:

{{UserInfo
|Bringing=gazebo, 🏳️🌈, purty fairy lights, speaker, tildagon x2, camping stove
|Village=Village:UK Refuge
|Arrival=2025-08-07
|Departure=2025-08-14
|EMail=me@felixweber.co.uk
|Languages=EN
|HackerSpace=Leighhack, Manchester
|NickName={{PAGENAME}}
}}

User:Felixwebercouk

2025-06-10T12:17:04Z

Felixwebercouk:

{{UserInfo
|Bringing=gazebo, 🏳️🌈, purty fairy lights, speaker, tildagon x2, camping stove
|Village=Village:UK Refuge
|Arrival=2025-08-06
|Departure=2025-08-14
|EMail=me@felixweber.co.uk
|Languages=EN
|HackerSpace=Leighhack, Manchester
|NickName={{PAGENAME}}
}}

Village:UK Refuge

2025-06-09T11:56:57Z

Felixwebercouk:

{{Village
|Has name=UK Refuge
|Has description=A village for those visiting from the UK, with social space and chill vibes.
|Related to village=Village:EMF
|Village is open to newcomers=Yes
|Provides session location=No
|Location=52.69204, 4.74995
|Has orga contact=tony.goacher@hotmail.co.uk
|On site orga contact=Email or +447789715991
|Village citizen count=9
|Village Needs power=Smaller Village (up to 2x 230V/Schuko)
|Village size needed=50
|Village hacktents num=0
|Village brings big stuff=No
|Village Special Vehicle=TrakTrike. About 2.5mx1.5m
|Village planning notes=A group of those visiting from the UK (primarily North West England) but anyone is welcome!
Social space (may?) include Manchester Hackspace's gazebo, a speaker, and villagers' furniture.
}}
A group of those visiting from the UK (primarily North West England) but anyone is welcome!
Social space to include a gazebo, fairy lights. a speaker, and villagers' furniture.

Location not considered(?) yet.

The awesome lists and tips below are borrowed from [[Village:TechInc]]:

<blockquote>
=for participants=

===things that would be nice to have at our village:===
* things that provide shade (very important), such as tarps
* a speaker for chill beats
* some chairs
* all the flags!!!
* enough extension cords and stekkerblokken, preferably meant for outdoor use
* a few outdoor-proof lights, for practical use or for aesthetics and vibes.

===pro tips for surviving hackercamps===
* earplugs for sleeping are a must
* shade is everything
* blinkenlights everywhere
* use glowsticks on tent wires to prevent accidents in the dark
* if a talk you want to attend is full or you're running late, you can watch them live at streaming.media.ccc.de.

remember to check the foodcourt page for current info on guaranteed food-for-money sources at camp https://wiki.why2025.org/Team:Foodcourt
of course, there are many other ways to acquire food at camp, but they typically require a bit more elbow grease and good timing.

</blockquote>

TrakTike needs about 800W to charge.

User:Felixwebercouk

2025-06-09T11:56:00Z

Felixwebercouk:

{{UserInfo
|Bringing=gazebo, maybe 2 chairs, fairy lights, bluetooth speaker, tildagon x2, multifuel stove, insanity
|Village=Village:UK Refuge
|Arrival=2025-08-06
|Departure=2025-08-14
|EMail=me@felixweber.co.uk
|Languages=EN
|HackerSpace=Leighhack, Manchester
|NickName={{PAGENAME}}
}}

User:Felixwebercouk

2025-06-09T11:48:04Z

Felixwebercouk:

{{UserInfo
|Bringing=bluetooth speaker, tildagon x2, multifuel stove, insanity
|Village=Village:UK Refuge
|Arrival=2025-08-06
|Departure=2025-08-14
|EMail=me@felixweber.co.uk
|Languages=EN
|HackerSpace=Leighhack, Manchester
|NickName={{PAGENAME}}
}}

File:Village-UK Refuge.svg

2025-06-03T12:34:35Z

Felixwebercouk:

User:Felixwebercouk

2025-06-02T22:00:54Z

Felixwebercouk:

{{UserInfo
|Bringing=bluetooth speaker, tildagon x2, multifuel stove, insanity
|Village=Village:UK Refuge
|EMail=me@felixweber.co.uk
|Languages=EN
|HackerSpace=Leighhack, Manchester
|NickName={{PAGENAME}}
}}

User:Felixwebercouk

2025-06-02T21:50:20Z

Felixwebercouk:

{{UserInfo
|Bringing=bluetooth speaker, tildagon x2, multifuel stove, insanity
|Village=Village:UK Refuge
|Languages=EN
|NickName={{PAGENAME}}
}}

Village:UK Refuge

2025-06-02T21:46:23Z

Felixwebercouk:

{{Village
|Has name=UK Refuge
|Has description=A village for those visiting from the UK, with social space and chill vibes.
|Related to village=Village:EMF
|Village is open to newcomers=Yes
|Provides session location=No
|Location=52.69204, 4.74995
|Has orga contact=tony.goacher@hotmail.co.uk
|On site orga contact=Email or +447789715991
|Village citizen count=9
|Village Needs power=Smaller Village (up to 2x 230V/Schuko)
|Village size needed=50
|Village hacktents num=0
|Village brings big stuff=No
|Village Special Vehicle=TrakTrike. About 2.5mx1.5m
|Village planning notes=A group of those visiting from the UK (primarily North West England) but anyone is welcome!
Social space (may?) include Manchester Hackspace's gazebo, a speaker, and villagers' furniture.
}}
A group of those visiting from the UK (primarily North West England) but anyone is welcome!
Social space (may?) include Manchester Hackspace's gazebo, a speaker, and villagers' furniture.

Location not considered(?) yet.

The awesome lists and tips below are borrowed from [[Village:TechInc]]:

<blockquote>
=for participants=

===things that would be nice to have at our village:===
* things that provide shade (very important), such as tarps
* a speaker for chill beats
* some chairs
* all the flags!!!
* enough extension cords and stekkerblokken, preferably meant for outdoor use
* a few outdoor-proof lights, for practical use or for aesthetics and vibes.

===pro tips for surviving hackercamps===
* earplugs for sleeping are a must
* shade is everything
* blinkenlights everywhere
* use glowsticks on tent wires to prevent accidents in the dark
* if a talk you want to attend is full or you're running late, you can watch them live at streaming.media.ccc.de.

remember to check the foodcourt page for current info on guaranteed food-for-money sources at camp https://wiki.why2025.org/Team:Foodcourt
of course, there are many other ways to acquire food at camp, but they typically require a bit more elbow grease and good timing.

</blockquote>

TrakTike needs about 800W to charge.

Village:UK Refuge

2025-06-01T13:27:39Z

Felixwebercouk:

{{Village
|Has name=UK Refuge
|Has description=A village for those from the UK who aren't in any other villages.
|Related to village=Village:EMF
|Village is open to newcomers=Yes
|Provides session location=No
|Location=52.69204, 4.74995
|Has orga contact=tony.goacher@hotmail.co.uk
|On site orga contact=Email or +447789715991
|Village citizen count=9
|Village Needs power=Smaller Village (up to 2x 230V/Schuko)
|Village size needed=50
|Village hacktents num=0
|Village brings big stuff=No
|Village Special Vehicle=TrakTrike. About 2.5mx1.5m
|Village planning notes=A group of those from the UK who do not fit into any other villages. Primarily a mix of people from the NW of England but anyone is welcome.
}}
A group of those from the UK who do not fit into any other villages. Primarily a mix of people from the NW of England but anyone is welcome.
TrakTike needs about 800W to charge.

User:Felixwebercouk

2025-06-01T08:11:53Z

Felixwebercouk:

{{UserInfo
|Village=Village:UK Refuge
|Languages=EN
|NickName={{PAGENAME}}
}}

User:Felixwebercouk

2025-05-31T20:50:20Z

Felixwebercouk: create user page

{{UserInfo
|NickName={{PAGENAME}}
|Languages=EN
|HackerSpace=
}}