write flash in ble_central\ble_app_uart_c

RE: write flash in ble_central\ble_app_uart_c

Amanda Hsieh — Thu, 29 Aug 2019 11:47:40 GMT

Hi Carey,

Please let me correct that:

In the SDK 12.3.0, we use the Softdevice dispatcher for fetching the event instead of sd_evt_get().

From ble_app_hrs example in 12.3.0:

/**@brief Function for dispatching a system event to interested modules.
 *
 * @details This function is called from the System event interrupt handler after a system
 *          event has been received.
 *
 * @param[in] sys_evt  System stack event.
 */
static void sys_evt_dispatch(uint32_t sys_evt)
{
    // Dispatch the system event to the fstorage module, where it will be
    // dispatched to the Flash Data Storage (FDS) module.
    fs_sys_event_handler(sys_evt);

    // Dispatch to the Advertising module last, since it will check if there are any
    // pending flash operations in fstorage. Let fstorage process system events first,
    // so that it can report correctly to the Advertising module.
    ble_advertising_on_sys_evt(sys_evt);
}

and the dispatcher for SoC events is set up in ble_stack_init():

    // Register with the SoftDevice handler module for BLE events.
    err_code = softdevice_sys_evt_handler_set(sys_evt_dispatch);
    APP_ERROR_CHECK(err_code);
}

Notice that all SoC events are forwarded to the fs_sys_event_handler(sys_evt);

Event forwarding from the SoftDevice is done via softdevice_handler.c (under nRF5_SDK_12.3\components\softdevice\common\softdevice_handler).

-Amanda H.

RE: write flash in ble_central\ble_app_uart_c

Carey — Wed, 28 Aug 2019 03:40:42 GMT

the Num_Page is 8, and i havn't found NRF_SDH_DISPATCH_MODEL in my project. I use

"sdk 12.3\examples\ble_central\ble_app_uart_c\pca10040"

RE: write flash in ble_central\ble_app_uart_c

Amanda Hsieh — Mon, 26 Aug 2019 11:09:19 GMT

Hi,

What is the value of Num_Page are you erasing?

What is the value of NRF_SDH_DISPATCH_MODEL in sdk_config.h?

-Amanda H.

RE: write flash in ble_central\ble_app_uart_c

Carey — Sat, 24 Aug 2019 13:51:30 GMT

when the code run to the sd_evt_get(), the MCU restart, if i do not kill nrf_delay_ms(50), the MCU would restart while run nrf_delay_ms.

RE: write flash in ble_central\ble_app_uart_c

Amanda Hsieh — Fri, 23 Aug 2019 10:48:27 GMT

Did you call sd_evt_get() and wait for the event NRF_EVT_FLASH_OPERATION_SUCCESS in the loop as this post?

Could you post the code?

-Amanda H.

RE: write flash in ble_central\ble_app_uart_c

Carey — Fri, 23 Aug 2019 08:10:15 GMT

but if i run sd_evt_get(), the result is same as the nrf_delay_ms: the MCU would restart, what's prablem with it ?

RE: write flash in ble_central\ble_app_uart_c

Amanda Hsieh — Wed, 21 Aug 2019 10:56:29 GMT

Hi Carey,

When sd_flash_page_erase() returns NRF_SUCCESS, that only means that the erase request was successfully submitted to the SoftDevice. It does _not_ mean that the erase operation has actually been completed yet. When the erase operation completes, the SoftDevice will generate an event interrupt, and you must call sd_evt_get() to consume it. Please see this post.

Therefore, rather than using a fixed delay, I would recommend you to wait for the event NRF_EVT_FLASH_OPERATION_SUCCESS, telling that the operation was successfully completed.

In addition, it is also good practice to check the returned error code when calling a function.

Please see the documentation of the sd_flash_page_erase() function. You will get one of the following events following the function call:

NRF_EVT_FLASH_OPERATION_SUCCESS - The command was successfully completed.
NRF_EVT_FLASH_OPERATION_ERROR - The command could not be started.

-Amanda H.

RE: write flash in ble_central\ble_app_uart_c

Carey — Tue, 20 Aug 2019 15:54:31 GMT

err_code = sd_flash_page_erase((uint32_t)(120));
APP_ERROR_CHECK(err_code);
nrf_delay_ms(50);

this is my code , the err_code return 0, but when it run to the nrf_delay_ms, the MCU restart. why?

RE: write flash in ble_central\ble_app_uart_c

Carey — Tue, 20 Aug 2019 14:21:47 GMT

OK, now i use (sd_flash_page_erase/sd_flash_write). can you give me some example for how to use this function?

RE: write flash in ble_central\ble_app_uart_c

Amanda Hsieh — Mon, 19 Aug 2019 13:22:03 GMT

Hi,

flash_word_write() typically tries to access the NVMC registers directly, but you shouldn't do that if you are running a SoftDevice. When the SoftDevice is enabled, the SoftDevice API for accessing flash should be used (sd_flash_page_erase/sd_flash_write).

Note: for writing and handling data storage in flash, the libraries nRF5 SDK v12.3.0: Flash Data Storage and nRF5 SDK v12.3.0: Experimental: Flash Storage are there to make it easier.

-Amanda H.