renamed modbus test to fit other tests I will add

software/test_modbus/src/main.c

@@ -0,0 +1,78 @@
+/* Testing MODBUS functionality
+   This code initializes a Modbus client, sets the zero point and the 2m point for water level,
+   and reads the water level in both meters and millimeters.
+   It uses the Zephyr RTOS and its Modbus library to communicate with a Modbus server.
+*/
+
+#include <zephyr/logging/log.h>
+#include <zephyr/kernel.h>
+#include <zephyr/drivers/gpio.h>
+
+#include "modbus.h"
+
+LOG_MODULE_REGISTER(main, CONFIG_LOG_DEFAULT_LEVEL);
+
+/* 1000 msec = 1 sec */
+#define SLEEP_TIME_MS 1000
+
+int main(void)
+{
+	int rc;
+
+	rc = mb_init_client();
+	if (rc != 0)
+	{
+		LOG_ERR("Failed to initialize Modbus client: %d", rc);
+		return rc;
+	}
+	LOG_INF("Modbus client initialized successfully");
+
+	double water_level = 0.0;
+	int water_level_mm, water_level_min_mm, water_level_max_mm = 0;
+
+	rc = mb_write_minimum_mm(42); // Set the zero point for water level
+	if (rc < 0)
+	{
+		LOG_ERR("Failed to write minimum water level: %d", rc);
+		return rc;
+	}
+	rc = mb_write_maximum_mm(2000); // Set the 2m point for water level
+	if (rc < 0)
+	{
+		LOG_ERR("Failed to write maximum water level: %d", rc);
+		return rc;
+	}
+	rc = mb_read_minimum_mm(&water_level_min_mm);
+	if (rc < 0)
+	{
+		LOG_ERR("Failed to read minimum water level: %d", rc);
+		return rc;
+	}
+	rc = mb_read_maximum_mm(&water_level_max_mm);
+	if (rc < 0)
+	{
+		LOG_ERR("Failed to read maximum water level: %d", rc);
+		return rc;
+	}
+	LOG_INF("Water zero point is set to: %dmm", water_level_min_mm);
+	LOG_INF("Water 2m point is set to: %dmm", water_level_max_mm);
+
+	/* Read water level */
+	rc = mb_read_water_level(&water_level);
+	if (rc < 0)
+	{
+		LOG_ERR("Failed to read water level: %d", rc);
+		return rc;
+	}
+	rc = mb_read_water_level_mm(&water_level_mm);
+	if (rc < 0)
+	{
+		LOG_ERR("Failed to read water level: %d", rc);
+		return rc;
+	}
+	LOG_INF("Water level: %.3fm", water_level);
+	LOG_INF("Water level: %dmm", water_level_mm);
+	LOG_INF("Modbus test completed successfully");
+
+	return 0;
+}