pstorage guide

[kk]

HI,everyone!

I want to use pstorage to store some data, so I followed the steps given by devzone.nordicsemi.com/.../, but it didn't work. Then I checked ecah function and found out the

pstorage_register (&p_example_param, &m_p_example_id)

return NRF_ERROR_NULL,and I can't find out where the problems come from.

Can someone point out the problem or give me an example for pstorage use?

Thank you very much!

[Nikita]

Are you using device manager along with your test psorage? You shouldn't initialize pstorage_init twice if you call example_pstorage_init after device manager init. Or you need to increase maximum number of applications PSTORAGE_MAX_APPLICATIONS in pstorage_platform.h.

UPD:

You can read more about pstorage here.

There is a pstorage example code here

Example handler:

// Event Notification Handler.
static void example_cb_handler(pstorage_handle_t  * handle,
                                uint8_t              op_code,
                                uint32_t             result,
                                uint8_t            * p_data,
                                uint32_t             data_len)
{
    switch(op_code)
    {
        case PSTORAGE_LOAD_OP_CODE:
           if (result == NRF_SUCCESS)
           {
               // Store operation successful.
           }
           else
           {
               // Store operation failed.
           }
           // Source memory can now be reused or freed.
           break;       
        case PSTORAGE_UPDATE_OP_CODE:
           if (result == NRF_SUCCESS)
           {
               // Update operation successful.
           }
           else
           {
               // Update operation failed.
           }
           break;
       case PSTORAGE_CLEAR_OP_CODE:
           if (result == NRF_SUCCESS)
           {
               // Clear operation successful.
           }
           else
           {
               // Clear operation failed.
           }
           break;
    }
}

[kk]

thank you for your fast reply!

Firstly,I did not use the device manager and I am sure the pstorage just be init once. Secondly,I have tried to increase the PSTORAGE_MAX_APPLICATIONS but nothing changed.

By the way, as the error NRF_ERROR_NULL means 'if NULL parameter has been passed', and I noticed the parameter m_p_example_id is just created without any initialization like this: static pstorage_handle_t m_p_example_id; will this be the problem? Thank you very much!

[kk]

sorry,I make a mistake! the NRF_ERROR_NULL comes from the NULL_PARAM_CHECK(p_module_param->cb); and I noticed my code just creat a parametr like this:p_example_param.cb = example_cb_handler; But I did not instantiate it because I don't konw how to. Can you give me an example to instantiate the cb_handler? Thank you very much!

[Stephen]

to instantiate a callback handler one would create a function that mtaches the type required. Specifically:

static void example_cb_handler( pstorage_handle_t *p_handle, uint8_t op_code, uint32_t result, uint8_t p_data, uint32_t dat_len ) { / do something */ }

"example_cb_handler", then, is a pointer to the function itself, which can then be assigned in a statement

example_param.cb = example_cb_handler;

Please look to generic c-coding guides for typedef creations of function pointers. Function pointers are extremely useful tools, and can be used to greatly simplify otherwise very complex code.