Writing to memory

Samko · May 1, 2023, 6:20pm

Hi, I would like to ask if there is an option of writing, calculations from software into flash memory, the thing is that 6KB of eeprom is not enough memory, for writing measurements from long term data collection.
Thank you

hub.martin · May 2, 2023, 12:57pm

Hi, you need to use STM32 HAL library functions from
sdk/stm/hal/inc/stm32l0xx_hal_flash.h
and
sdk/stm/hal/inc/stm32l0xx_hal_flash_ex.h (which contains also erase commands)

You need unlock the flash controller, erase the correct flash page (if it does not contain 0xFFs.), write data and lock page.

In case of more rewrite-demanding we suggest using some libraries that manages wear-leveling.
Also STM has free EEPROM emulation driver, that is using Flash as a NVM storage and manages some wear leveling and garbage collection.
https://www.st.com/resource/en/application_note/an4894-eeprom-emulation-techniques-and-software-for-stm32-microcontrollers-stmicroelectronics.pdf

github.com

rohitsam/STM32-code-snippets/blob/master/FLASH/user-code-read-and-write-flash.md

# USER-CODE-TO-READ-AND-WRITE-FROM-FLASH-MEMORY

In most cases we do require to save config parameters to some memory.
Since Most stm32 controllers doesn't have any internal eeprom, we can make use of the available Flash to write the data.

1. > save_data(uint32_t Address,uint32_t data) 
takes 32bit address and data as args


```
#include "stm32f0xx_hal.h"


void save_data(uint32_t Address,uint32_t data){

    HAL_FLASH_Unlock();
	FLASH_EraseInitTypeDef EraseInitStruct;
	EraseInitStruct.TypeErase = FLASH_TYPEERASE_PAGES;
	EraseInitStruct.PageAddress = Address;
	EraseInitStruct.NbPages = 1;

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