Write Application Data to Flash with pstorage

[Marius R.]

Hi,

i am having trouble to understand and use flash to store data. First of all as far as i understand ble_flash is obsolete and replaced by the pstorage module, correct?

What i want to achieve is, i want to save user settings to flash to be able to set my system to the same state after it has been e.g. reset. Therefore i need to write, erase, read and update existing settings to/in flash.

I read the following documentation part and used it as base of my own code: devzone.nordicsemi.com/.../a00018.html

Do i need to change any addresses in pstorage_platform to match it to my application? I was not sure whether i need to change code in pstorage_platform or not so i didn't changed anything.

The coded i copied from the documentation and the code i added is shown in the file attached.

The pstorage_init is called in my init_app_data_flash_manager function and after the ble_stack_init. Futhermore pstorage_init is called only once.

    // Initialize in main
leds_init();
timers_init();
gpiote_init();
buttons_init();
ble_stack_init();
init_app_data_flash_manager();
scheduler_init();    
gap_params_init();
services_init();
advertising_init();
conn_params_init();
sec_params_init();

My code does the following like descibed in the documentation. I register one block with specific size (in bytes) after pstorage_init. The handle generated while registering is saved and later used to read/write to get a block_handle using pstorage_block_identifier_get. Afterwards this block handle is used to read/write using pstorage_load and pstorage_store.

To test all this I write and read to flash after my device is disconnected (see BLE_GAP_EVT_DISCONNECTED). I also stop adversting to read and write to flash so radio should be inactiv.

            case BLE_GAP_EVT_DISCONNECTED:
        m_conn_handle = BLE_CONN_HANDLE_INVALID;
        
            //advertising_start();
			//test_app_system_settings is empty, test data is generated in save_settings_to_flash

					save_settings_to_flash(&test_app_system_settings);
					read_settings_from_flash(&test_app_system_settings);
        break;

When i debug it the array i read in read_settings_from_flash is empty (just zero).

Can anyone tell me what i am doing wrong and/or help me get it working?

Regards

code.c

Edit: I almost forgot the maybe most importat thing: How do I manage to read and write to the same address every time cause the address i wrote to in the first place is gone after a reset and saving it to flash is not possible cuase this would require a address i dont know after reset as well?

[wlgrd]

Have a look at this module as well (Device Manager) devzone.nordicsemi.com/.../a00937.html . It should take quite good care of what you're trying to do.

[Marius R.]

Thanks Christian. I already took a look at it and i got to say it is a lot of code and thus hard to get trough. I added the update function to my save_setting function but stiil get no results.

[Marius R.]

2. EDIT: Just to confirm whether i get this right or not. If my application hits one of the op code states below in my param.cb = app_data_flash_manager_cb_handler implementation registered with pstorage_register(&param,&handle_base). Then i know an error occured when i e.g. tried to load data from flash. Correct??? Cause apperantly i hit them all the time so i guess not a single operation i try to exec works/is successful.

OP CODE: #define PSTORAGE_ERROR_OP_CODE 0x01

#define PSTORAGE_STORE_OP_CODE 0x02

#define PSTORAGE_LOAD_OP_CODE 0x03

#define PSTORAGE_CLEAR_OP_CODE 0x04

#define PSTORAGE_UPDATE_OP_CODE 0x05 Regards

[Wojtek]

I don't know how are You using pstorage module, but in my case (which i consider as correct) it works like this:

1. I flash my code do device
2. I store some data in pstorage (after blank check - if not empty, erase before write), and read it back succesfully
3. I flash my device with new code.
4. I can read data stored by previous application succesfully
5. In nrf studio i use "erase all"
6. i cannot read data anymore.

I think your implementation may miss something like getting the same flash memory block as previous one.

[Marius R.]

How do you get the same flash block? My app performs the following operations everytime it gets switched on:

// init pstorage module

err_code = pstorage_init();

APP_ERROR_CHECK(err_code);

// register flash space in pstorage module

param.block_size = 64;

param.block_count = 1;

param.cb = app_data_flash_manager_cb_handler;

err_code = pstorage_register(&param,&handle_base);

APP_ERROR_CHECK(err_code);

I am not sure but i assumed i will get the same flash part if the size i request is the same everytime.