diff --git a/main/README.md b/main/README.md
new file mode 100644
index 0000000..9f39420
--- /dev/null
+++ b/main/README.md
@@ -0,0 +1,20 @@
+# Quack Firmware source code
+
+### Supported SDK versions:
+
+The code is designed to be build with ESP-IDF SDK version 4.2.2. To workaround some patchs or limitations of this specific release, you need to apply the patch located in the SDK subfolder
+
+### Unsupported mouse conversions:
+
+Functions are grouped into "domains" in different files. Each functions has a prefix for its own domain.
+For example, adb_init() is the init function for the ADB Bus and is located in the adb.c source file.
+
+List of relevant files:
+- adb.* Apple Desktop Bus related functions
+- blue.* Bluetooth related functions
+- esp_hid_gap.* HID GAP library from Espressif
+- gpio.* raw GPIO related functions
+- led.* LED related functions
+- m4848.h Header for Apple Hockey Puck mouse over Bluetooth emulation
+- main.c Everything start here
+- quad.c Quadrature related functions (mouse port)