Basic code for writing to EEPROM.

fw/Core/Inc/config.h

@@ -11,6 +11,7 @@
 /* TODO: add comments to everything */
 
 #include "stdint.h"
+#include "stm32l0xx.h"
 
 #define VENDOR_NAME_LENGTH			64
 #define	PRODUCT_CODE_LENGTH			64
@@ -18,9 +19,22 @@
 #define REVISION_LENGTH				16
 #define SERIAL_NUMBER_LENGTH		64
 
+#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 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
+
+
 
 typedef struct
 {
@@ -37,9 +51,15 @@ typedef struct
 	uint16_t led_co2_alert_limit2;
 } config_t;
 
-int8_t read_config(config_t *config);
+int8_t config_read(config_t *config);
 
-int8_t write_config(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_ */
 

fw/Core/Inc/main.h

@@ -53,6 +53,7 @@ extern "C" {
 #include "sht4x.h"
 #include "sps30.h"
 #include "modbus.h"
+#include "config.h"
 /* USER CODE END Includes */
 
 /* Exported types ------------------------------------------------------------*/

fw/Core/Src/config.c

@@ -7,12 +7,118 @@
 
 #include "config.h"
 
-int8_t read_config(config_t *config)
+int8_t config_read(config_t *config)
 {
 	return CONFIG_OK;
 }
 
-int8_t write_config(config_t *config)
+int8_t config_write(config_t *config)
 {
+	/* Unlock the EEPROM */
+	if (eeprom_unlock() != EEPROM_OK)
+	{
+		return EEPROM_UNLOCK_ERROR;
+	}
+	/* 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)
+	{
+		return EEPROM_WRITE_ERROR;
+	}
+
+	if (eeprom_program_halfword(DATA_EEPROM_BASE_ADDR+2, 0x4321) != EEPROM_OK)
+	{
+		return EEPROM_WRITE_ERROR;
+	}
+
+	if (eeprom_program_word(DATA_EEPROM_BASE_ADDR + (4), 0x12345678) != EEPROM_OK)
+	{
+		return EEPROM_WRITE_ERROR;
+	}
+
+	for (uint8_t i = 0; i < 16; i ++)
+	{
+		eeprom_program_byte(DATA_EEPROM_BASE_ADDR + 8 + i, i+1);
+	}
+
+	if (eeprom_lock() != EEPROM_OK)
+	{
+		return EEPROM_LOCK_ERROR;
+	}
 	return CONFIG_OK;
 }
+
+static int8_t eeprom_lock(void)
+{
+   while ((FLASH->SR & FLASH_SR_BSY) != 0) /* Wait for FLASH to be free */
+   {
+/* TODO:  insert timeout test */
+   }
+
+   FLASH->PECR = FLASH->PECR & ~(FLASH_PECR_ERRIE | FLASH_PECR_EOPIE); /* disable flash interrupts */
+   FLASH->PECR = FLASH->PECR | FLASH_PECR_PELOCK; /* Lock memory with PELOCK */
+
+   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 */
+   {
+/*  TODO: insert timeout test */
+   }
+   if ((FLASH->PECR & FLASH_PECR_PELOCK) != 0) /* If PELOCK is locked */
+   {
+	   /* Unlock PELOCK */
+      FLASH->PEKEYR = FLASH_PEKEY1; /* PEKEY1 */
+      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)
+	{
+	  return EEPROM_WRITE_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;
+}

fw/Core/Src/main.c

@@ -196,6 +196,14 @@ 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 */