diff --git a/fw/Core/Inc/config.h b/fw/Core/Inc/config.h
index 2e47aab..d75e37f 100644
--- a/fw/Core/Inc/config.h
+++ b/fw/Core/Inc/config.h
@@ -2,7 +2,7 @@
  * config.h
  *
  *  Created on: Sep 5, 2021
- *      Author: dukenuc
+ *      Author: david
  */
 
 #ifndef INC_CONFIG_H_
@@ -12,54 +12,78 @@
 
 #include "stdint.h"
 #include "stm32l0xx.h"
+/* DESCRIPTION OF THE DATA STRUCTURE */
+/*
+ * Data are divided into two groups:
+ * A) DEVICE DESCRIPTION
+ * 		Can not be changed by the user.
+ * 		These data can be only read.
+ * 		These data are:
+ * 		* VENDOR NAME
+ * 		* PRODUCT CODE
+ * 		* PRODUCT NAME
+ * 		* REVISION
+ * 		* SERIAL NUMBER
+ * B) DEVICE CONFIGURATION
+ * 		Can be changed by the user.
+ * 		These data are:
+ * 		* MODBUS ADDRESS - Modbus Address of the device. Default is 254
+ * 		* LED ON - Whether the CO2 Level Indication LED should be on or off
+ * 		* LED CO2 ALERT LIMIT 1 - CO2 Level when the LED color changes Green<->Yellow
+ * 		* LED CO2 ALERT LIMIT 2 - CO2 Level when the LED color changes Yellow<->Red
+ *
+ * Device description data can be accessed using direct readout from the memory
+ * Device configuration data can be accessed using config_t struct.
+ */
+#define	MODBUS_ADDR_LENGTH						2
+#define CONFIG_LED_ON_LENGTH					1
+#define CONFIG_LED_ALERT1_LENGTH				2
+#define CONFIG_LED_ALERT2_LENGTH				2
+#define VENDOR_NAME_LENGTH						64
+#define	PRODUCT_CODE_LENGTH						64
+#define	PRODUCT_NAME_LENGTH						64
+#define REVISION_LENGTH							16
+#define SERIAL_NUMBER_LENGTH					64
 
-#define VENDOR_NAME_LENGTH			64
-#define	PRODUCT_CODE_LENGTH			64
-#define	PRODUCT_NAME_LENGTH			64
-#define REVISION_LENGTH				16
-#define SERIAL_NUMBER_LENGTH		64
+#define EEPROM_ADDR_START 						((uint32_t)0x08080000)
+#define EEPROM_ADDR_END 						((uint32_t)0x080801FF)
 
-#define DATA_EEPROM_BASE_ADDR ((uint32_t)0x08080000) /* Data EEPROM base address */
-#define DATA_EEPROM_END_ADDR ((uint32_t)0x080801FF) /* Data EEPROM end address */
+#define CONFIG_EEPROM_ADDR_MODBUS_ADDR			EEPROM_ADDR_START
+#define CONFIG_EEPROM_ADDR_LED_ON_ADDR			CONFIG_EEPROM_ADDR_MODBUS_ADDR 		+ MODBUS_ADDR_LENGTH
+#define CONFIG_EEPROM_ADDR_LED_ALERT1_ADDR		CONFIG_EEPROM_ADDR_LED_ON_ADDR		+ CONFIG_LED_ON_LENGTH
+#define CONFIG_EEPROM_ADDR_LED_ALERT2_ADDR		CONFIG_EEPROM_ADDR_LED_ALERT1_ADDR 	+ CONFIG_LED_ALERT1_LENGTH
+#define CONFIG_EEPROM_ADDR_VENDOR_NAME			CONFIG_EEPROM_ADDR_LED_ALERT2_ADDR 	+ CONFIG_LED_ALERT2_LENGTH
+#define CONFIG_EEPROM_ADDR_PRODUCT_CODE			CONFIG_EEPROM_ADDR_VENDOR_NAME 		+ VENDOR_NAME_LENGTH
+#define CONFIG_EEPROM_ADDR_PRODUCT_NAME			CONFIG_EEPROM_ADDR_PRODUCT_CODE 	+ PRODUCT_CODE_LENGTH
+#define CONFIG_EEPROM_ADDR_REVISION				CONFIG_EEPROM_ADDR_PRODUCT_NAME 	+ PRODUCT_NAME_LENGTH
+#define CONFIG_EEPROM_ADDR_SERIAL_NUMBER		CONFIG_EEPROM_ADDR_REVISION			+ REVISION_LENGTH
 
-#define FLASH_PEKEY1				0x89ABCDEF
-#define FLASH_PEKEY2				0x02030405
-
-#define CONFIG_OK					0
-#define CONFIG_ERROR				-1
-
-#define EEPROM_OK					0
-#define EEPROM_ERROR				-1
-#define EEPROM_UNLOCK_ERROR			-2
-#define EEPROM_LOCK_ERROR			-3
-#define EEPROM_WRITE_ERROR			-4
+#define FLASH_PEKEY1							0x89ABCDEF
+#define FLASH_PEKEY2							0x02030405
 
+#define CONFIG_OK								0
+#define CONFIG_ERROR							-1
 
+#define EEPROM_OK								0
+#define EEPROM_ERROR							-1
+#define EEPROM_UNLOCK_ERROR						-2
+#define EEPROM_LOCK_ERROR						-3
+#define EEPROM_WRITE_ERROR						-4
+#define EEPROM_ADDR_ERROR						-5
 
 typedef struct
 {
-	/* DEVICE ID */
-	uint8_t vendor_name[VENDOR_NAME_LENGTH];
-	uint8_t product_code[PRODUCT_CODE_LENGTH];
-	uint8_t product_name[PRODUCT_NAME_LENGTH];
-	uint8_t revision[REVISION_LENGTH];
-	uint8_t serial_number[SERIAL_NUMBER_LENGTH];
-
-	/* DEVICE SPECIFIC CONFIG */
+	/* DEVICE CONFIG */
 	uint8_t led_on;
 	uint16_t led_co2_alert_limit1;
 	uint16_t led_co2_alert_limit2;
+
+	/* MODBUS CONFIG */
+	uint16_t modbus_addr;
 } config_t;
 
 int8_t config_read(config_t *config);
-
 int8_t config_write(config_t *config);
 
-static int8_t eeprom_lock(void);
-static int8_t eeprom_unlock(void);
-static int8_t eeprom_program_byte(uint32_t addr, uint8_t ee_data);
-static int8_t eeprom_program_halfword(uint32_t addr, uint16_t ee_data);
-static int8_t eeprom_program_word(uint32_t addr, uint32_t ee_data);
-
 #endif /* INC_CONFIG_H_ */
 
diff --git a/fw/Core/Src/config.c b/fw/Core/Src/config.c
index 4348c4c..cee056c 100644
--- a/fw/Core/Src/config.c
+++ b/fw/Core/Src/config.c
@@ -2,13 +2,28 @@
  * config.c
  *
  *  Created on: Sep 5, 2021
- *      Author: dukenuc
+ *      Author: david
  */
 
 #include "config.h"
 
+/* Function to lock the EEPROM */
+static int8_t eeprom_lock(void);
+/* Function to unlock the EEPROM */
+static int8_t eeprom_unlock(void);
+/* Function to write one byte to the EEPROM */
+/* IMPORTANT: EEPROM must be unlocked first */
+static int8_t eeprom_program_byte(uint32_t addr, uint8_t ee_data);
+/* Function to write two bytes to the EEPROM */
+/* IMPORTANT: EEPROM must be unlocked first */
+static int8_t eeprom_program_halfword(uint32_t addr, uint16_t ee_data);
+
 int8_t config_read(config_t *config)
 {
+	config->modbus_addr = *(uint16_t *) CONFIG_EEPROM_ADDR_MODBUS_ADDR;
+	config->led_on = *(uint8_t *) CONFIG_EEPROM_ADDR_LED_ON_ADDR;
+	config->led_co2_alert_limit1 = *(uint16_t *) CONFIG_EEPROM_ADDR_LED_ALERT1_ADDR;
+	config->led_co2_alert_limit2 = *(uint16_t *) CONFIG_EEPROM_ADDR_LED_ALERT2_ADDR;
 	return CONFIG_OK;
 }
 
@@ -21,26 +36,32 @@ int8_t config_write(config_t *config)
 	}
 	/* Reset the ERASE and DATA bits in the FLASH_PECR register to disable any residual erase */
 	FLASH->PECR = FLASH->PECR & ~(FLASH_PECR_ERASE | FLASH_PECR_DATA);
-	if (eeprom_program_byte(DATA_EEPROM_BASE_ADDR, 0xab) != EEPROM_OK)
+
+	/* Write MODBUS ADDRESS */
+	if (eeprom_program_halfword(CONFIG_EEPROM_ADDR_MODBUS_ADDR, config->modbus_addr)  != EEPROM_OK)
 	{
 		return EEPROM_WRITE_ERROR;
 	}
 
-	if (eeprom_program_halfword(DATA_EEPROM_BASE_ADDR+2, 0x4321) != EEPROM_OK)
+	/* Write LED ON */
+	if (eeprom_program_byte(CONFIG_EEPROM_ADDR_LED_ON_ADDR, config->led_on)  != EEPROM_OK)
 	{
 		return EEPROM_WRITE_ERROR;
 	}
 
-	if (eeprom_program_word(DATA_EEPROM_BASE_ADDR + (4), 0x12345678) != EEPROM_OK)
+	/* Write LED CO2 ALERT LIMIT 1 */
+	if (eeprom_program_halfword(CONFIG_EEPROM_ADDR_LED_ALERT1_ADDR, config->led_co2_alert_limit1) != EEPROM_OK)
 	{
 		return EEPROM_WRITE_ERROR;
 	}
 
-	for (uint8_t i = 0; i < 16; i ++)
+	/* Write LED CO2 ALERT LIMIT 2 */
+	if (eeprom_program_halfword(CONFIG_EEPROM_ADDR_LED_ALERT2_ADDR, config->led_co2_alert_limit2) != EEPROM_OK)
 	{
-		eeprom_program_byte(DATA_EEPROM_BASE_ADDR + 8 + i, i+1);
+		return EEPROM_WRITE_ERROR;
 	}
 
+	/* Lock EEPROM*/
 	if (eeprom_lock() != EEPROM_OK)
 	{
 		return EEPROM_LOCK_ERROR;
@@ -61,8 +82,6 @@ static int8_t eeprom_lock(void)
    return EEPROM_OK;
 }
 
-/* Unlock the EEPROM: */
-
 static int8_t eeprom_unlock(void)
 {
    while ((FLASH->SR & FLASH_SR_BSY) != 0) /* Wait for FLASH to be free */
@@ -76,49 +95,40 @@ static int8_t eeprom_unlock(void)
       FLASH->PEKEYR = FLASH_PEKEY2; /* PEKEY2 */
    }
    FLASH->PECR = FLASH->PECR | (FLASH_PECR_ERRIE | FLASH_PECR_EOPIE); /* enable flash interrupts */
-
    return EEPROM_OK;
 }
 
-/**
-* Brief This function programs a word of data EEPROM.
-* The ERASE bit and DATA bit are cleared in PECR at the beginning
-* words are automatically erased if required before programming
-* Param addr is the 32-bit EEPROM address to program, data is the 32 bit word to program
-* Retval None
-*/
-
-/* NOTE: The EEPROM must be unlocked and the flash interrupts must have been enabled prior to calling this function.*/
-
 static int8_t eeprom_program_byte(uint32_t addr, uint8_t ee_data)
 {
-	*(uint8_t *)(addr) = ee_data; /* write data to EEPROM */
-	//__WFI();
-	if (*(uint8_t *)(addr) != ee_data)
+	if ((EEPROM_ADDR_START <= addr) && (addr <= EEPROM_ADDR_END - 1))
 	{
-	  return EEPROM_WRITE_ERROR;
+		*(uint8_t *)(addr) = ee_data; /* write data to EEPROM */
+		/* TODO: Why is not the WFI triggering on FLASH Interrupt if it is supposed to be enabled? */
+		//__WFI();
+		if (*(uint8_t *)(addr) != ee_data)
+		{
+			return EEPROM_WRITE_ERROR;
+		}
+		return EEPROM_OK;
+	} else
+	{
+		return EEPROM_ADDR_ERROR;
 	}
-	return EEPROM_OK;
 }
 static int8_t eeprom_program_halfword(uint32_t addr, uint16_t ee_data)
 {
-   *(uint16_t *)(addr) = ee_data; /* write data to EEPROM */
-   //__WFI();
-   if (*(uint16_t *)(addr) != ee_data)
-   {
-      return EEPROM_WRITE_ERROR;
-   }
-	return EEPROM_OK;
-}
-
-
-static int8_t eeprom_program_word(uint32_t addr, uint32_t ee_data)
-{
-   *(uint32_t *)(addr) = ee_data; /* write data to EEPROM */
-   //__WFI();
-   if (*(uint32_t *)(addr) != ee_data)
-   {
-	  return EEPROM_WRITE_ERROR;
-   }
-	return EEPROM_OK;
+	if ((EEPROM_ADDR_START <= addr) && (addr <= EEPROM_ADDR_END - 2))
+	{
+		*(uint16_t *)(addr) = ee_data; /* write data to EEPROM */
+		/* TODO: Why is not the WFI triggering on FLASH Interrupt if it is supposed to be enabled? */
+		//__WFI();
+		if (*(uint16_t *)(addr) != ee_data)
+		{
+			return EEPROM_WRITE_ERROR;
+		}
+		return EEPROM_OK;
+	} else
+	{
+		return EEPROM_ADDR_ERROR;
+	}
 }
diff --git a/fw/Core/Src/main.c b/fw/Core/Src/main.c
index d736673..82e98f4 100644
--- a/fw/Core/Src/main.c
+++ b/fw/Core/Src/main.c
@@ -196,14 +196,6 @@ int main(void)
   scd4x_start_periodic_measurement();
   uint8_t scd4x_is_connected = 1;
   uint8_t sps30_is_connected = 0;
-
-
-	config_t dummy_config;
-	int8_t config_write_err = config_write(&dummy_config);
-
-	uint32_t eeprom_dato1 = *(uint8_t *)(DATA_EEPROM_BASE_ADDR);
-	uint32_t eeprom_dato2 = *(uint16_t *)(DATA_EEPROM_BASE_ADDR+2);
-	uint32_t eeprom_dato3 = *(uint32_t *)(DATA_EEPROM_BASE_ADDR+4);
   /* USER CODE END 2 */
 
   /* Infinite loop */