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/hello_world/CMakeLists.txt

@@ -1,6 +0,0 @@
-cmake_minimum_required(VERSION 3.20)
-
-find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
-project(hello_world)
-
-target_sources(app PRIVATE src/main.c)

software/apps/hello_world/prj.conf

@@ -1,4 +0,0 @@
-
-CONFIG_CONSOLE=y
-CONFIG_LOG=y
-CONFIG_UART_CONSOLE=y

software/apps/hello_world/src/main.c

@@ -1,9 +0,0 @@
-#include <zephyr/kernel.h>
-#include <zephyr/sys/printk.h>
-
-int main(void)
-{
-	printk("Hello World! %s\n", CONFIG_BOARD);
-	return 0;
-}
-

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)
+project(slave_node LANGUAGES C)
-list(APPEND KCONFIG_SOURCE ${CMAKE_CURRENT_SOURCE_DIR}/../../modules/valve/Kconfig)
+zephyr_include_directories(../../include)
-list(APPEND KCONFIG_SOURCE ${CMAKE_CURRENT_SOURCE_DIR}/../../modules/fwu/Kconfig)
+add_subdirectory(../../lib lib)
-
+target_sources(app PRIVATE src/main.c)
-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
-)

software/apps/slave_node/Kconfig

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

software/apps/slave_node/boards/bluepill_f103rb.conf

@@ -3,4 +3,5 @@ CONFIG_UART_CONSOLE=n
 
 # Enable RTT console
 CONFIG_RTT_CONSOLE=y
-CONFIG_USE_SEGGER_RTT=y
+CONFIG_USE_SEGGER_RTT=y
+CONFIG_SHELL_BACKEND_RTT=y

software/apps/slave_node/cdc-acm.overlay

@@ -0,0 +1,10 @@
+&zephyr_udc0 {
+	cdc_acm_uart0: cdc_acm_uart0 {
+		compatible = "zephyr,cdc-acm-uart";
+
+		modbus0 {
+			compatible = "zephyr,modbus-serial";
+			status = "okay";
+		};
+	};
+};

software/apps/slave_node/overlay-cdc-acm.conf

@@ -0,0 +1,4 @@
+CONFIG_USB_DEVICE_STACK=y
+CONFIG_USB_DEVICE_PRODUCT="Modbus slave node"
+CONFIG_UART_LINE_CTRL=y
+CONFIG_USB_DEVICE_INITIALIZE_AT_BOOT=n

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 <lib/modbus_server.h>
-#include <valve.h>
+#include <lib/valve.h>
-#include <fwu.h>
+#include <lib/fwu.h>
 
 LOG_MODULE_REGISTER(main, LOG_LEVEL_INF);
 

software/apps/stm32g431_tests/CMakeLists.txt

@@ -1,6 +0,0 @@
-cmake_minimum_required(VERSION 3.20)
-
-find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
-project(stm32g431_tests)
-
-target_sources(app PRIVATE src/main.c)

software/apps/stm32g431_tests/prj.conf

@@ -1,4 +0,0 @@
-
-CONFIG_CONSOLE=y
-CONFIG_LOG=y
-CONFIG_UART_CONSOLE=y

software/apps/stm32g431_tests/src/main.c

@@ -1,9 +0,0 @@
-#include <zephyr/kernel.h>
-#include <zephyr/sys/printk.h>
-
-int main(void)
-{
-	printk("Hello World! %s\n", CONFIG_BOARD);
-	return 0;
-}
-

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

@@ -1,19 +1,23 @@
 #include <zephyr/kernel.h>
-#include "modbus_server.h"
+#include <zephyr/drivers/uart.h>
+#include <zephyr/device.h>
 #include <zephyr/modbus/modbus.h>
 #include <zephyr/logging/log.h>
 #include <zephyr/settings/settings.h>
 #include <zephyr/sys/reboot.h>
-#include "valve.h"
+#include <lib/modbus_server.h>
-#include "fwu.h"
+#include <lib/valve.h>
+#include <lib/fwu.h>
+
+#include <zephyr/usb/usb_device.h>
 
 LOG_MODULE_REGISTER(modbus_server, LOG_LEVEL_INF);
 
 static int modbus_iface;
 static struct modbus_iface_param server_param = {
 	.mode = MODBUS_MODE_RTU,
-	.server = { .user_cb = NULL, .unit_id = 1 },
+	.server = {.user_cb = NULL, .unit_id = 1},
-	.serial = { .baud = 19200, .parity = UART_CFG_PARITY_NONE },
+	.serial = {.baud = 19200, .parity = UART_CFG_PARITY_NONE},
 };
 
 static uint16_t watchdog_timeout_s = 0;
@@ -27,7 +31,8 @@ static void watchdog_timer_handler(struct k_timer *timer_id)
 
 static inline void reset_watchdog(void)
 {
-	if (watchdog_timeout_s > 0) {
+	if (watchdog_timeout_s > 0)
+	{
 		k_timer_start(&watchdog_timer, K_SECONDS(watchdog_timeout_s), K_NO_WAIT);
 	}
 }
@@ -35,11 +40,20 @@ static inline void reset_watchdog(void)
 static int holding_reg_rd(uint16_t addr, uint16_t *reg)
 {
 	reset_watchdog();
-	switch (addr) {
+	switch (addr)
-	case REG_HOLDING_MAX_OPENING_TIME_S: *reg = valve_get_max_open_time(); break;
+	{
-	case REG_HOLDING_MAX_CLOSING_TIME_S: *reg = valve_get_max_close_time(); break;
+	case REG_HOLDING_MAX_OPENING_TIME_S:
-	case REG_HOLDING_WATCHDOG_TIMEOUT_S: *reg = watchdog_timeout_s; break;
+		*reg = valve_get_max_open_time();
-	default: *reg = 0; break;
+		break;
+	case REG_HOLDING_MAX_CLOSING_TIME_S:
+		*reg = valve_get_max_close_time();
+		break;
+	case REG_HOLDING_WATCHDOG_TIMEOUT_S:
+		*reg = watchdog_timeout_s;
+		break;
+	default:
+		*reg = 0;
+		break;
 	}
 	return 0;
 }
@@ -47,11 +61,21 @@ static int holding_reg_rd(uint16_t addr, uint16_t *reg)
 static int holding_reg_wr(uint16_t addr, uint16_t reg)
 {
 	reset_watchdog();
-	switch (addr) {
+	switch (addr)
+	{
 	case REG_HOLDING_VALVE_COMMAND:
-		if (reg == 1) { valve_open(); }
+		if (reg == 1)
-		else if (reg == 2) { valve_close(); }
+		{
-		else if (reg == 0) { valve_stop(); }
+			valve_open();
+		}
+		else if (reg == 2)
+		{
+			valve_close();
+		}
+		else if (reg == 0)
+		{
+			valve_stop();
+		}
 		break;
 	case REG_HOLDING_MAX_OPENING_TIME_S:
 		valve_set_max_open_time(reg);
@@ -61,23 +85,27 @@ static int holding_reg_wr(uint16_t addr, uint16_t reg)
 		break;
 	case REG_HOLDING_WATCHDOG_TIMEOUT_S:
 		watchdog_timeout_s = reg;
-		if (watchdog_timeout_s > 0) {
+		if (watchdog_timeout_s > 0)
+		{
 			LOG_INF("Watchdog enabled with %u s timeout.", watchdog_timeout_s);
 			reset_watchdog();
-		} else {
+		}
+		else
+		{
 			LOG_INF("Watchdog disabled.");
 			k_timer_stop(&watchdog_timer);
 		}
 		break;
 	case REG_HOLDING_DEVICE_RESET:
-		if (reg == 1) {
+		if (reg == 1)
+		{
 			LOG_WRN("Modbus reset command received. Rebooting...");
 			sys_reboot(SYS_REBOOT_WARM);
 		}
 		break;
-    default:
+	default:
-        fwu_handler(addr, reg);
+		fwu_handler(addr, reg);
-        break;
+		break;
 	}
 	return 0;
 }
@@ -86,13 +114,32 @@ static int input_reg_rd(uint16_t addr, uint16_t *reg)
 {
 	reset_watchdog();
 	uint32_t uptime_s = k_uptime_get_32() / 1000;
-	switch (addr) {
+	switch (addr)
-	case REG_INPUT_VALVE_STATE_MOVEMENT: *reg = (valve_get_movement() << 8) | (valve_get_state() & 0xFF); break;
+	{
-	case REG_INPUT_MOTOR_CURRENT_MA: *reg = valve_get_motor_current(); break;
+	case REG_INPUT_VALVE_STATE_MOVEMENT:
-	case REG_INPUT_UPTIME_SECONDS_LOW: *reg = (uint16_t)(uptime_s & 0xFFFF); break;
+		*reg = (valve_get_movement() << 8) | (valve_get_state() & 0xFF);
-	case REG_INPUT_UPTIME_SECONDS_HIGH: *reg = (uint16_t)(uptime_s >> 16); break;
+		break;
-	case REG_INPUT_FWU_LAST_CHUNK_CRC: *reg = fwu_get_last_chunk_crc(); break;
+	case REG_INPUT_MOTOR_CURRENT_MA:
-	default: *reg = 0; break;
+		*reg = valve_get_motor_current();
+		break;
+	case REG_INPUT_UPTIME_SECONDS_LOW:
+		*reg = (uint16_t)(uptime_s & 0xFFFF);
+		break;
+	case REG_INPUT_UPTIME_SECONDS_HIGH:
+		*reg = (uint16_t)(uptime_s >> 16);
+		break;
+	case REG_INPUT_FWU_LAST_CHUNK_CRC:
+		*reg = fwu_get_last_chunk_crc();
+		break;
+	case REG_INPUT_FIRMWARE_VERSION_MAJOR_MINOR:
+		*reg = (0 << 8) | 0;
+		break;
+	case REG_INPUT_FIRMWARE_VERSION_PATCH:
+		*reg = 2;
+		break;
+	default:
+		*reg = 0;
+		break;
 	}
 	return 0;
 }
@@ -109,8 +156,28 @@ int modbus_server_init(void)
 {
 	k_timer_init(&watchdog_timer, watchdog_timer_handler, NULL);
 	const char iface_name[] = {DEVICE_DT_NAME(MODBUS_NODE)};
+#if DT_NODE_HAS_COMPAT(DT_PARENT(MODBUS_NODE), zephyr_cdc_acm_uart)
+	const struct device *const dev = DEVICE_DT_GET(DT_PARENT(MODBUS_NODE));
+	uint32_t dtr = 0;
+
+	if (!device_is_ready(dev) || usb_enable(NULL))
+	{
+		return 0;
+	}
+
+	while (!dtr)
+	{
+		uart_line_ctrl_get(dev, UART_LINE_CTRL_DTR, &dtr);
+		k_sleep(K_MSEC(100));
+	}
+
+	LOG_INF("Client connected to server on %s", dev->name);
+#endif
 	modbus_iface = modbus_iface_get_by_name(iface_name);
-	if (modbus_iface < 0) { return modbus_iface; }
+	if (modbus_iface < 0)
+	{
+		return modbus_iface;
+	}
 	server_param.server.user_cb = &mbs_cbs;
 	return modbus_init_server(modbus_iface, server_param);
 }
@@ -122,12 +189,13 @@ int modbus_reconfigure(uint32_t baudrate, uint8_t unit_id)
 
 	int ret = modbus_init_server(modbus_iface, server_param);
 
-    if (ret == 0) {
+	if (ret == 0)
-        settings_save_one("modbus/baudrate", &baudrate, sizeof(baudrate));
+	{
-        settings_save_one("modbus/unit_id", &unit_id, sizeof(unit_id));
+		settings_save_one("modbus/baudrate", &baudrate, sizeof(baudrate));
-    }
+		settings_save_one("modbus/unit_id", &unit_id, sizeof(unit_id));
+	}
 
-    return ret;
+	return ret;
 }
 
 uint32_t modbus_get_baudrate(void) { return server_param.serial.baud; }

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 <lib/modbus_server.h>
-#include <valve.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)