feat(refactor): Restructure project for improved modularity and clarity

This commit introduces a major refactoring of the project structure to align
with Zephyr's recommended multi-application and library organization.

Key changes include:
- Relocation of custom modules from 'software/modules/' to 'software/lib/'.
- Introduction of a central 'software/CMakeLists.txt' to manage application
  and library subdirectories.
- Creation of new Kconfig files for 'software/' and 'software/apps/slave_node/'
  to define project-wide and application-specific configurations.
- Removal of the 'gateway' and 'stm32g431_tests' applications.
- Removal of 'shell_modbus.c' and 'shell_system.c' from 'slave_node' application's
  direct source files, indicating a shift towards library-based shell commands.
- Updates to 'software/apps/slave_node/CMakeLists.txt', 'prj.conf', and
  'boards/bluepill_f103rb.conf' to reflect the new structure and dependencies.

.vscode/settings.json

@@ -0,0 +1,5 @@
+{
+    "files.associations": {
+        "fwu.h": "c"
+    }
+}

lib/fwu/CMakeLists.txt

@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.20)
+
+project(fwu)
+
+target_sources(fwu PRIVATE src/fwu.c)
+target_include_directories(fwu PUBLIC include)

lib/modbus_server/CMakeLists.txt

@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.20)
+
+project(modbus_server)
+
+target_sources(modbus_server PRIVATE src/modbus_server.c)
+target_include_directories(modbus_server PUBLIC include)

lib/valve/CMakeLists.txt

@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.20)
+
+project(valve)
+
+target_sources(valve PRIVATE src/valve.c)
+target_include_directories(valve PUBLIC include)

software/CMakeLists.txt

@@ -1,8 +0,0 @@
-cmake_minimum_required(VERSION 3.13.1)
-
-project(software)
-
-add_subdirectory(modules/modbus_server)
-add_subdirectory(modules/valve)
-add_subdirectory(modules/fwu)
-add_subdirectory(apps/stm32g431_tests)

software/Kconfig

@@ -0,0 +1 @@
+rsource "lib/Kconfig"

software/apps/slave_node/CMakeLists.txt

@@ -1,27 +1,8 @@
 cmake_minimum_required(VERSION 3.20)
 
-# Point BOARD_ROOT and DTS_ROOT to the 'software' directory, which contains 'boards'.
-list(APPEND BOARD_ROOT ${CMAKE_CURRENT_SOURCE_DIR}/../..)
-
 find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
-project(slave_node)
 
-list(APPEND KCONFIG_SOURCE ${CMAKE_CURRENT_SOURCE_DIR}/../../modules/modbus_server/Kconfig)
-list(APPEND KCONFIG_SOURCE ${CMAKE_CURRENT_SOURCE_DIR}/../../modules/valve/Kconfig)
-list(APPEND KCONFIG_SOURCE ${CMAKE_CURRENT_SOURCE_DIR}/../../modules/fwu/Kconfig)
-
-target_include_directories(app PRIVATE
-    ${CMAKE_CURRENT_SOURCE_DIR}/../../modules/valve/include
-    ${CMAKE_CURRENT_SOURCE_DIR}/../../modules/modbus_server/include
-    ${CMAKE_CURRENT_SOURCE_DIR}/../../modules/fwu/include
-)
-
-# Add the source files from the app and the libraries
-target_sources(app PRIVATE
-    src/main.c
-    src/shell_modbus.c
-    src/shell_system.c
-    ${CMAKE_CURRENT_SOURCE_DIR}/../../modules/valve/src/valve.c
-    ${CMAKE_CURRENT_SOURCE_DIR}/../../modules/modbus_server/src/modbus_server.c
-    ${CMAKE_CURRENT_SOURCE_DIR}/../../modules/fwu/src/fwu.c
-)
+project(slave_node LANGUAGES C)
+zephyr_include_directories(../../include)
+add_subdirectory(../../lib lib)
+target_sources(app PRIVATE src/main.c)

software/apps/slave_node/Kconfig

@@ -0,0 +1,2 @@
+rsource "../../lib/Kconfig"
+source "Kconfig.zephyr"

software/apps/slave_node/boards/bluepill_f103rb.conf

@@ -4,3 +4,4 @@ CONFIG_UART_CONSOLE=n
 # Enable RTT console
 CONFIG_RTT_CONSOLE=y
 CONFIG_USE_SEGGER_RTT=y
+CONFIG_SHELL_BACKEND_RTT=y

software/apps/slave_node/prj.conf

@@ -4,7 +4,6 @@ CONFIG_LOG=y
 
 # Enable Shell
 CONFIG_SHELL=y
-CONFIG_SHELL_BACKEND_RTT=y
 CONFIG_REBOOT=y
 
 # Enable Settings Subsystem

software/apps/slave_node/src/main.c

@@ -1,9 +1,9 @@
 #include <zephyr/kernel.h>
 #include <zephyr/settings/settings.h>
 #include <zephyr/logging/log.h>
-#include <modbus_server.h>
-#include <valve.h>
-#include <fwu.h>
+#include <lib/modbus_server.h>
+#include <lib/valve.h>
+#include <lib/fwu.h>
 
 LOG_MODULE_REGISTER(main, LOG_LEVEL_INF);
 

software/lib/CMakeLists.txt

@@ -0,0 +1,5 @@
+add_subdirectory_ifdef(CONFIG_LIB_FWU fwu)
+add_subdirectory_ifdef(CONFIG_LIB_MODBUS_SERVER modbus_server)
+add_subdirectory_ifdef(CONFIG_LIB_VALVE valve)
+add_subdirectory_ifdef(CONFIG_SHELL_SYSTEM shell_system)
+add_subdirectory_ifdef(CONFIG_SHELL_MODBUS shell_modbus)

software/lib/Kconfig

@@ -0,0 +1,8 @@
+menu "Irrigation system software libraries"
+
+rsource "fwu/Kconfig"
+rsource "modbus_server/Kconfig"
+rsource "valve/Kconfig"
+rsource "shell_system/Kconfig"
+rsource "shell_modbus/Kconfig"
+endmenu

software/lib/fwu/CMakeLists.txt

@@ -0,0 +1 @@
+zephyr_library_sources(fwu.c)

software/lib/fwu/Kconfig

@@ -1,5 +1,5 @@
-config FWU
+config LIB_FWU
     bool "Enable Firmware Update Library"
     default y
     help
-      Enable the Firmware Update module.
+      Enable the Firmware Update Library.

software/lib/fwu/fwu.c

@@ -1,8 +1,8 @@
-#include "fwu.h"
 #include <zephyr/kernel.h>
 #include <zephyr/sys/crc.h>
 #include <zephyr/sys/byteorder.h>
 #include <zephyr/logging/log.h>
+#include <lib/fwu.h>
 
 LOG_MODULE_REGISTER(fwu, LOG_LEVEL_INF);
 

software/lib/modbus_server/CMakeLists.txt

@@ -0,0 +1 @@
+zephyr_library_sources(modbus_server.c)

software/lib/modbus_server/Kconfig

@@ -0,0 +1,5 @@
+config LIB_MODBUS_SERVER
+    bool "Enable Modbus Server Library"
+    default y
+    help
+      Enable the Modbus Server Library.

software/lib/modbus_server/modbus_server.c

@@ -5,9 +5,9 @@
 #include <zephyr/logging/log.h>
 #include <zephyr/settings/settings.h>
 #include <zephyr/sys/reboot.h>
-#include "modbus_server.h"
-#include "valve.h"
-#include "fwu.h"
+#include <lib/modbus_server.h>
+#include <lib/valve.h>
+#include <lib/fwu.h>
 
 #include <zephyr/usb/usb_device.h>
 
@@ -135,7 +135,7 @@ static int input_reg_rd(uint16_t addr, uint16_t *reg)
 		*reg = (0 << 8) | 0;
 		break;
 	case REG_INPUT_FIRMWARE_VERSION_PATCH:
-		*reg = 1;
+		*reg = 2;
 		break;
 	default:
 		*reg = 0;

software/lib/shell_modbus/CMakeLists.txt

@@ -0,0 +1 @@
+zephyr_library_sources(shell_modbus.c)

software/lib/shell_modbus/Kconfig

@@ -0,0 +1,5 @@
+config SHELL_MODBUS
+    bool "Enable Shell Modbus"
+    default y
+    help
+      Enable the modnbus shell commands.

software/lib/shell_modbus/shell_modbus.c

@@ -1,7 +1,7 @@
 #include <zephyr/shell/shell.h>
 #include <stdlib.h>
-#include <modbus_server.h>
-#include <valve.h>
+#include <lib/modbus_server.h>
+#include <lib/valve.h>
 
 static int cmd_modbus_set_baud(const struct shell *sh, size_t argc, char **argv)
 {

software/lib/shell_system/CMakeLists.txt

@@ -0,0 +1 @@
+zephyr_library_sources(shell_system.c)

software/lib/shell_system/Kconfig

@@ -0,0 +1,5 @@
+config SHELL_SYSTEM
+    bool "Enable Shell System"
+    default y
+    help
+      Enable the system commands.

software/lib/valve/CMakeLists.txt

@@ -0,0 +1 @@
+zephyr_library_sources(valve.c)

software/lib/valve/Kconfig

@@ -1,5 +1,5 @@
-config VALVE
+config LIB_VALVE
     bool "Enable Valve Library"
     default y
     help
-      Enable the Valve module.
+      Enable the Valve Library.

software/lib/valve/valve.c

@@ -1,7 +1,7 @@
-#include "valve.h"
 #include <zephyr/kernel.h>
 #include <zephyr/settings/settings.h>
 #include <zephyr/logging/log.h>
+#include <lib/valve.h>
 
 LOG_MODULE_REGISTER(valve, LOG_LEVEL_INF);
 

software/modules/fwu/CMakeLists.txt

@@ -1,7 +0,0 @@
-cmake_minimum_required(VERSION 3.13.1)
-include($ENV{ZEPHYR_BASE}/cmake/app/boilerplate.cmake NO_POLICY_SCOPE)
-
-project(fwu)
-
-target_sources(app PRIVATE src/fwu.c)
-target_include_directories(app PUBLIC include)

software/modules/modbus_server/CMakeLists.txt

@@ -1,7 +0,0 @@
-cmake_minimum_required(VERSION 3.13.1)
-include($ENV{ZEPHYR_BASE}/cmake/app/boilerplate.cmake NO_POLICY_SCOPE)
-
-project(modbus_server)
-
-target_sources(app PRIVATE src/modbus_server.c)
-target_include_directories(app PUBLIC include)

software/modules/modbus_server/Kconfig

@@ -1,5 +0,0 @@
-config MODBUS_SERVER
-    bool "Enable Modbus Server Library"
-    default y
-    help
-      Enable the Modbus Server module.

software/modules/valve/CMakeLists.txt

@@ -1,7 +0,0 @@
-cmake_minimum_required(VERSION 3.13.1)
-include($ENV{ZEPHYR_BASE}/cmake/app/boilerplate.cmake NO_POLICY_SCOPE)
-
-project(valve)
-
-target_sources(app PRIVATE src/valve.c)
-target_include_directories(app PUBLIC include)