diff --git a/docs/dev-stories.md b/docs/dev-stories.md
index e12e057..9fcb2da 100644
--- a/docs/dev-stories.md
+++ b/docs/dev-stories.md
@@ -1,5 +1,4 @@
 # Stories architecture
-
 ## Story location
 
 The stories are located on a SD-Card flash memory. The following file system formats are supported by openStoryTeller:
@@ -9,7 +8,7 @@ The stories are located on a SD-Card flash memory. The following file system for
 
 Connect OpenStoryTeller to your computer using a USB cable, a USB-disk will show up on your file explorer.
 
-## Story tree
+## Story root tree
 
 A typical folder organisation is showed here:
 
@@ -17,8 +16,41 @@ A typical folder organisation is showed here:
 
 At the root of the SD-Card, a special index file named `index.ost` must be present. It contains the list of installed stories as well as other informations about each story.
 
-## Index file format
+## Story folder organisation
 
-TLV format.
+A story folder name must be a UUID v4 string.
+
+It must contains:
+- A project file in JSON named `project.json`
+- A pre-compiled story binary name `story.c32`
+- A directory named `assets`
+
+The assets directory must contains all the resource files for the story (sounds, images...).
+
+# Index file format
+
+## General principle
+
+This binary file is encoded using a simple TLV format (Type Lenght Value) supporting the following types:
 
 
+| Type  | encoding |
+| ----- | ----- |
+| Object | 0xE7   |
+|  Array | 0xAB   |
+|  String |  0x3D  |
+|  Integer |  0x77  |
+|  Real |  0xB8  |
+
+Each Type is encoded on a byte.
+
+The Length is encoded on two bytes, little endian. The length indicates the size of the Value.
+
+## Application on the Index File Forma
+
+- Array
+   - Object
+      - String (UUID, folder name of the story)
+      - String (title image file name)
+      - String (sound title file name)
+
diff --git a/docs/guide-devkit-pico.md b/docs/guide-devkit-pico.md
index 2e5e91c..f6998b5 100644
--- a/docs/guide-devkit-pico.md
+++ b/docs/guide-devkit-pico.md
@@ -6,7 +6,7 @@ This is the official development kit. It offers the following advantages:
 3. Low wiring/soldering: usage of a motherboard 
 4. SWD debug port
 
-Current status: ON DEVELOPMENT
+Current status: Firmware and software are completed. Build instructions under writing.
 
 ![pico](./images/devkit-pico.jpg)
 
@@ -57,17 +57,41 @@ The pins usage for this bundle is indicated by the folling wirering. OST pins ar
 
 ![pico](./images/picow-pinout_ost.png)
 
-# Bundle build guide
-
-
 # Firmware flashing
 
+## Get the firmware binary
+
+Download the right file for your bundle on the Github project page : [Github project page](https://github.com/arabine/open-story-teller) 
+
+For the Raspberry Pi Pico bundle, the executable is a ELF file extension.
+
+## Procedure
+
+You can program the Pico without any software thanks to the UF2 file system driver embedded in the Pico bootloader.
+
+- Press the Boot button located on the Marbe Pico
+- Without releasing the button, connect the Marbe Pico to your computer using a USB-C cable
+- Release the button
+- A new disk drive should popup on your file system
+
+Button position:
+
+![pico](./images/marble-pico.png)
+
+
+UF2 disk on your file explorer:
 
 ![pico](./images/pico-uf2-ubuntu.png)
 
 
+Just drag and drop the firmware image in this directory, wait for the programming and firmware reboot.
 
-# How to build from the source code
+# Bundle build guide
+
+TODO
+
+
+# How to build the firmare image from the source code
 
 ## Clone the repository
 
diff --git a/docs/images/marble-pico.png b/docs/images/marble-pico.png
new file mode 100644
index 0000000..e830427
Binary files /dev/null and b/docs/images/marble-pico.png differ
diff --git a/docs/intro-getting-started.md b/docs/intro-getting-started.md
index 1668dd7..c5cd0cc 100644
--- a/docs/intro-getting-started.md
+++ b/docs/intro-getting-started.md
@@ -7,18 +7,17 @@ This documentation will guide you to make your own story teller. You can choose
 Before starting, here is a complete list of links where you'll find project information:
 
 - :octopus: [Github](https://github.com/arabine/open-story-teller): source code for the firmware, the player and the story editor, issue tracking
-- [Itch.io](https://d8s-apps.itch.io/open-story-teller): Download page for the Story Editor and various player versions.
+- Free stories community (in French) [Discord](https://monurl.ca/DiscordLuniiYT)
+- My Discord channel for this project: https://discord.gg/4TW4B3R4Ye
 
 ## Helping
 
 You can help in various ways:
 
 - Report bugs on Github (open an new issue)
-- Propose patches, ideas, mechanical drawings, ports (open an issue)
+- Propose patches, ideas, mechanical drawings for enclosures, ports (open an issue)
 - Translate stuff
 
-Reach me on Discord: [Discord](https://monurl.ca/DiscordLuniiYT)
-
 ## Where to start
 
 Before building your own hardware, make sure you have a minimal knowledge of basic electronics. You may have to solder some wires, but nothing's complicated.
diff --git a/software/library/story_project.cpp b/software/library/story_project.cpp
index a141180..09756e6 100644
--- a/software/library/story_project.cpp
+++ b/software/library/story_project.cpp
@@ -27,7 +27,8 @@ void StoryProject::New(const std::string &uuid, const std::string &file_path)
 #define TLV_ARRAY_TYPE  0xAB
 #define TLV_OBJECT_TYPE  0xE7
 #define TLV_STRING_TYPE  0x3D
-
+#define TLV_INTEGER     0x77
+#define TLV_REAL        0xB8
 
 class Tlv
 {