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/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)
 
-# Define a variable for the lib directory
-set(LIB_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../../lib)
-
-# Add the include directories for the libraries
-target_include_directories(app PRIVATE
-    ${LIB_DIR}/valve
-    ${LIB_DIR}/modbus_server
-    ${LIB_DIR}/fwu
-)
-
-# 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
-    ${LIB_DIR}/valve/valve.c
-    ${LIB_DIR}/modbus_server/modbus_server.c
-    ${LIB_DIR}/fwu/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

@@ -0,0 +1,7 @@
+# Disable UART console
+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/boards/weact_stm32g431_core.overlay

@@ -0,0 +1,9 @@
+&usart1 {
+	modbus0 {
+		compatible = "zephyr,modbus-serial";
+		status = "okay";
+	};
+	status = "okay";
+    pinctrl-0 = <&usart1_tx_pa9 &usart1_rx_pa10>;
+    pinctrl-names = "default";
+};

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

@@ -2,16 +2,8 @@
 CONFIG_CONSOLE=y
 CONFIG_LOG=y
 
-# Disable UART console
-CONFIG_UART_CONSOLE=n
-
-# Enable RTT console
-CONFIG_RTT_CONSOLE=y
-CONFIG_USE_SEGGER_RTT=y
-
 # Enable Shell
 CONFIG_SHELL=y
-CONFIG_SHELL_BACKEND_RTT=y
 CONFIG_REBOOT=y
 
 # Enable Settings Subsystem
@@ -28,3 +20,4 @@ CONFIG_UART_INTERRUPT_DRIVEN=y
 CONFIG_MODBUS=y
 CONFIG_MODBUS_ROLE_SERVER=y
 CONFIG_MODBUS_BUFFER_SIZE=256
+

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/include/lib/modbus_server.h

@@ -0,0 +1,52 @@
+#ifndef MODBUS_SERVER_H
+#define MODBUS_SERVER_H
+
+#include <stdint.h>
+
+/**
+ * @brief Modbus Input Register Addresses.
+ */
+enum {
+	/* Valve Control & Status */
+	REG_INPUT_VALVE_STATE_MOVEMENT        = 0x0000,
+	REG_INPUT_MOTOR_CURRENT_MA            = 0x0001,
+	/* Digital Inputs */
+	REG_INPUT_DIGITAL_INPUTS_STATE        = 0x0020,
+	REG_INPUT_BUTTON_EVENTS               = 0x0021,
+	/* System Config & Status */
+	REG_INPUT_FIRMWARE_VERSION_MAJOR_MINOR = 0x00F0,
+	REG_INPUT_FIRMWARE_VERSION_PATCH      = 0x00F1,
+	REG_INPUT_DEVICE_STATUS               = 0x00F2,
+	REG_INPUT_UPTIME_SECONDS_LOW          = 0x00F3,
+	REG_INPUT_UPTIME_SECONDS_HIGH         = 0x00F4,
+	/* Firmware Update */
+	REG_INPUT_FWU_LAST_CHUNK_CRC          = 0x0100,
+};
+
+/**
+ * @brief Modbus Holding Register Addresses.
+ */
+enum {
+	/* Valve Control */
+	REG_HOLDING_VALVE_COMMAND             = 0x0000,
+	REG_HOLDING_MAX_OPENING_TIME_S        = 0x0001,
+	REG_HOLDING_MAX_CLOSING_TIME_S        = 0x0002,
+	/* Digital Outputs */
+	REG_HOLDING_DIGITAL_OUTPUTS_STATE     = 0x0010,
+	/* System Config */
+	REG_HOLDING_WATCHDOG_TIMEOUT_S        = 0x00F0,
+	REG_HOLDING_DEVICE_RESET              = 0x00F1,
+	/* Firmware Update */
+	REG_HOLDING_FWU_COMMAND               = 0x0100,
+	REG_HOLDING_FWU_CHUNK_OFFSET_LOW      = 0x0101,
+	REG_HOLDING_FWU_CHUNK_OFFSET_HIGH     = 0x0102,
+	REG_HOLDING_FWU_CHUNK_SIZE            = 0x0103,
+	REG_HOLDING_FWU_DATA_BUFFER           = 0x0180,
+};
+
+int modbus_server_init(void);
+int modbus_reconfigure(uint32_t baudrate, uint8_t unit_id);
+uint32_t modbus_get_baudrate(void);
+uint8_t modbus_get_unit_id(void);
+
+#endif // MODBUS_SERVER_H

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

@@ -0,0 +1,5 @@
+config LIB_FWU
+    bool "Enable Firmware Update Library"
+    default y
+    help
+      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

@@ -1,60 +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 "fwu.h"
+#include <lib/modbus_server.h>
+#include <lib/valve.h>
+#include <lib/fwu.h>
+
+#include <zephyr/usb/usb_device.h>
 
 LOG_MODULE_REGISTER(modbus_server, LOG_LEVEL_INF);
 
-
-/**
- * @brief Modbus Input Register Addresses.
- */
-enum {
-	/* Valve Control & Status */
-	REG_INPUT_VALVE_STATE_MOVEMENT        = 0x0000,
-	REG_INPUT_MOTOR_CURRENT_MA            = 0x0001,
-	/* Digital Inputs */
-	REG_INPUT_DIGITAL_INPUTS_STATE        = 0x0020,
-	REG_INPUT_BUTTON_EVENTS               = 0x0021,
-	/* System Config & Status */
-	REG_INPUT_FIRMWARE_VERSION_MAJOR_MINOR = 0x00F0,
-	REG_INPUT_FIRMWARE_VERSION_PATCH      = 0x00F1,
-	REG_INPUT_DEVICE_STATUS               = 0x00F2,
-	REG_INPUT_UPTIME_SECONDS_LOW          = 0x00F3,
-	REG_INPUT_UPTIME_SECONDS_HIGH         = 0x00F4,
-	/* Firmware Update */
-	REG_INPUT_FWU_LAST_CHUNK_CRC          = 0x0100,
-};
-
-/**
- * @brief Modbus Holding Register Addresses.
- */
-enum {
-	/* Valve Control */
-	REG_HOLDING_VALVE_COMMAND             = 0x0000,
-	REG_HOLDING_MAX_OPENING_TIME_S        = 0x0001,
-	REG_HOLDING_MAX_CLOSING_TIME_S        = 0x0002,
-	/* Digital Outputs */
-	REG_HOLDING_DIGITAL_OUTPUTS_STATE     = 0x0010,
-	/* System Config */
-	REG_HOLDING_WATCHDOG_TIMEOUT_S        = 0x00F0,
-	/* Firmware Update */
-	REG_HOLDING_FWU_COMMAND               = 0x0100,
-	REG_HOLDING_FWU_CHUNK_OFFSET_LOW      = 0x0101,
-	REG_HOLDING_FWU_CHUNK_OFFSET_HIGH     = 0x0102,
-	REG_HOLDING_FWU_CHUNK_SIZE            = 0x0103,
-	REG_HOLDING_FWU_DATA_BUFFER           = 0x0180,
-};
-
 static int modbus_iface;
 static struct modbus_iface_param server_param = {
 	.mode = MODBUS_MODE_RTU,
-	.server = { .user_cb = NULL, .unit_id = 1 },
-	.serial = { .baud = 19200, .parity = UART_CFG_PARITY_NONE },
+	.server = {.user_cb = NULL, .unit_id = 1},
+	.serial = {.baud = 19200, .parity = UART_CFG_PARITY_NONE},
 };
 
 static uint16_t watchdog_timeout_s = 0;
@@ -68,7 +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);
 	}
 }
@@ -76,11 +40,20 @@ static inline void reset_watchdog(void)
 static int holding_reg_rd(uint16_t addr, uint16_t *reg)
 {
 	reset_watchdog();
-	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_WATCHDOG_TIMEOUT_S: *reg = watchdog_timeout_s; break;
-	default: *reg = 0; break;
+	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_WATCHDOG_TIMEOUT_S:
+		*reg = watchdog_timeout_s;
+		break;
+	default:
+		*reg = 0;
+		break;
 	}
 	return 0;
 }
@@ -88,11 +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(); }
-		else if (reg == 2) { valve_close(); }
-		else if (reg == 0) { valve_stop(); }
+		if (reg == 1)
+		{
+			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);
@@ -102,23 +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:
-        fwu_handler(addr, reg);
-        break;
+	default:
+		fwu_handler(addr, reg);
+		break;
 	}
 	return 0;
 }
@@ -127,13 +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) {
-	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_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;
-	default: *reg = 0; break;
+	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_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;
 }
@@ -150,8 +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);
 }
@@ -163,12 +189,13 @@ int modbus_reconfigure(uint32_t baudrate, uint8_t unit_id)
 
 	int ret = modbus_init_server(modbus_iface, server_param);
 
-    if (ret == 0) {
-        settings_save_one("modbus/baudrate", &baudrate, sizeof(baudrate));
-        settings_save_one("modbus/unit_id", &unit_id, sizeof(unit_id));
-    }
+	if (ret == 0)
+	{
+		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/modbus_server/modbus_server.h

@@ -1,11 +0,0 @@
-#ifndef MODBUS_SERVER_H
-#define MODBUS_SERVER_H
-
-#include <stdint.h>
-
-int modbus_server_init(void);
-int modbus_reconfigure(uint32_t baudrate, uint8_t unit_id);
-uint32_t modbus_get_baudrate(void);
-uint8_t modbus_get_unit_id(void);
-
-#endif // MODBUS_SERVER_H

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

@@ -0,0 +1,5 @@
+config LIB_VALVE
+    bool "Enable Valve Library"
+    default y
+    help
+      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/tools/modbus_tool/modbus_tool.py

@@ -54,33 +54,74 @@ def format_uptime(seconds):
 
 def poll_status(slave_id, interval):
     global status_data
+    reconnect_attempts = 0
+    max_reconnect_attempts = 5
+    reconnect_delay = 1 # seconds
+
     while not stop_event.is_set():
-        if update_status["running"]: time.sleep(interval); continue
-        new_data = {"error": None}
+        if update_status["running"]:
+            time.sleep(interval)
+            continue
+
+        new_data = {}
         try:
+            if not client.is_socket_open():
+                reconnect_attempts += 1
+                if reconnect_attempts >= max_reconnect_attempts:
+                    new_data["error"] = f"Failed to reconnect after {max_reconnect_attempts} attempts. Exiting."
+                    stop_event.set()
+                    break
+                
+                # Attempt to connect
+                if client.connect():
+                    reconnect_attempts = 0
+                    new_data["error"] = None # Clear error on successful reconnect
+                else:
+                    new_data["error"] = f"Connection lost. Attempting to reconnect ({reconnect_attempts}/{max_reconnect_attempts})..."
+                    time.sleep(reconnect_delay)
+                    continue
+
+            # If connected, try to read data
             ir_valve = client.read_input_registers(REG_INPUT_VALVE_STATE_MOVEMENT, count=2, slave=slave_id)
             ir_dig = client.read_input_registers(REG_INPUT_DIGITAL_INPUTS_STATE, count=2, slave=slave_id)
             ir_sys = client.read_input_registers(REG_INPUT_FIRMWARE_VERSION_MAJOR_MINOR, count=5, slave=slave_id)
             hr_valve = client.read_holding_registers(REG_HOLDING_MAX_OPENING_TIME_S, count=2, slave=slave_id)
             hr_dig = client.read_holding_registers(REG_HOLDING_DIGITAL_OUTPUTS_STATE, count=1, slave=slave_id)
             hr_sys = client.read_holding_registers(REG_HOLDING_WATCHDOG_TIMEOUT_S, count=1, slave=slave_id)
+
             for res in [ir_valve, ir_dig, ir_sys, hr_valve, hr_dig, hr_sys]:
-                if res.isError(): raise ModbusException(str(res))
+                if res.isError():
+                    raise ModbusException(str(res))
             
             valve_state_raw = ir_valve.registers[0]
-            movement_map = {0: "Idle", 1: "Opening", 2: "Closing", 3: "Error"}; state_map = {0: "Closed", 1: "Open"}
-            new_data["movement"] = movement_map.get(valve_state_raw >> 8, 'Unknown'); new_data["state"] = state_map.get(valve_state_raw & 0xFF, 'Unknown')
-            new_data["motor_current"] = f"{ir_valve.registers[1]} mA"; new_data["open_time"] = f"{hr_valve.registers[0]}s"; new_data["close_time"] = f"{hr_valve.registers[1]}s"
-            new_data["digital_inputs"] = f"0x{ir_dig.registers[0]:04X}"; new_data["button_events"] = f"0x{ir_dig.registers[1]:04X}"; new_data["digital_outputs"] = f"0x{hr_dig.registers[0]:04X}"
+            movement_map = {0: "Idle", 1: "Opening", 2: "Closing", 3: "Error"}
+            state_map = {0: "Closed", 1: "Open"}
+            new_data["movement"] = movement_map.get(valve_state_raw >> 8, 'Unknown')
+            new_data["state"] = state_map.get(valve_state_raw & 0xFF, 'Unknown')
+            new_data["motor_current"] = f"{ir_valve.registers[1]} mA"
+            new_data["open_time"] = f"{hr_valve.registers[0]}s"
+            new_data["close_time"] = f"{hr_valve.registers[1]}s"
+            new_data["digital_inputs"] = f"0x{ir_dig.registers[0]:04X}"
+            new_data["button_events"] = f"0x{ir_dig.registers[1]:04X}"
+            new_data["digital_outputs"] = f"0x{hr_dig.registers[0]:04X}"
             
-            fw_major = ir_sys.registers[0] >> 8; fw_minor = ir_sys.registers[0] & 0xFF; fw_patch = ir_sys.registers[1]
+            fw_major = ir_sys.registers[0] >> 8
+            fw_minor = ir_sys.registers[0] & 0xFF
+            fw_patch = ir_sys.registers[1]
             uptime_seconds = (ir_sys.registers[4] << 16) | ir_sys.registers[3]
-            new_data["firmware"] = f"v{fw_major}.{fw_minor}.{fw_patch}"; new_data["device_status"] = "OK" if ir_sys.registers[2] == 0 else "ERROR"
-            new_data["uptime"] = format_uptime(uptime_seconds); new_data["watchdog"] = f"{hr_sys.registers[0]}s"
+            new_data["firmware"] = f"v{fw_major}.{fw_minor}.{fw_patch}"
+            new_data["device_status"] = "OK" if ir_sys.registers[2] == 0 else "ERROR"
+            new_data["uptime"] = format_uptime(uptime_seconds)
+            new_data["watchdog"] = f"{hr_sys.registers[0]}s"
+            new_data["error"] = None # Clear any previous error on successful read
+            reconnect_attempts = 0 # Reset attempts on successful communication
         except Exception as e:
-            new_data["error"] = f"Error: {e}"
-        with status_lock: status_data = new_data
-        time.sleep(interval)
+            new_data["error"] = f"Communication Error: {e}. Closing connection."
+            client.close() # Close connection to force reconnect attempt in next loop
+        finally:
+            with status_lock:
+                status_data = new_data
+            time.sleep(interval)
 
 def firmware_update_thread(slave_id, filepath):
     global update_status
@@ -225,11 +266,11 @@ def main_menu(stdscr, slave_id):
                 elif selected_option == "Set Watchdog":
                     input_mode, input_prompt, input_target_reg = True, "Enter Watchdog Timeout (s): ", REG_HOLDING_WATCHDOG_TIMEOUT_S
                 elif selected_option == "Reset Node":
-                    client.write_register(REG_HOLDING_DEVICE_RESET, 1, slave=slave_id)
-                    message = "-> Sent RESET command"
-                elif selected_option == "Firmware Update":
-                    client.write_register(REG_HOLDING_DEVICE_RESET, 1, slave=slave_id)
-                    message = "-> Sent RESET command"
+                    try:
+                        client.write_register(REG_HOLDING_DEVICE_RESET, 1, slave=slave_id)
+                        message = "-> Sent RESET command. Node should reboot."
+                    except Exception as e:
+                        message = f"-> Error sending reset: {e}"
                 elif selected_option == "Firmware Update":
                     filepath = file_browser(stdscr)
                     if filepath:
@@ -245,9 +286,9 @@ def main_menu(stdscr, slave_id):
             stdscr.addstr(h // 2 + 1, w // 2 - 25, msg.ljust(50))
         else:
             with status_lock: current_data = status_data.copy()
+            bold, normal = curses.color_pair(1) | curses.A_BOLD, curses.color_pair(1)
             if current_data.get("error"): stdscr.addstr(0, 0, current_data["error"], curses.color_pair(3) | curses.A_BOLD)
             else:
-                bold, normal = curses.color_pair(1) | curses.A_BOLD, curses.color_pair(1)
                 col1, col2, col3, col4 = 2, 30, 58, 88
                 stdscr.addstr(1, col1, "State:", bold); stdscr.addstr(1, col1 + 18, str(current_data.get('state', 'N/A')), normal)
                 stdscr.addstr(2, col1, "Movement:", bold); stdscr.addstr(2, col1 + 18, str(current_data.get('movement', 'N/A')), normal)