When the app timer is started and the timing time is less than 8Ms, fstore cannot be used to write user data

[summer]

hi,I used NRF52833 to debug the program, and I used the ble_app_hid_mouse project in SDK16 to debug the fstore function ,and the file path is E:\nrf52833\nRF5SDK160098a08e2\examples\ble_peripheral\ble_app_hids_mouse\pca10056\s140\arm5_no_packs.

    Now, I see some problems debugging the fstore functionality,when I started app_timer, when the timing time was less than 8ms, I found that when using fsrore to write data to flash, it would prompt an error.。but when I turn off the timer or the timer time is greater than 8MS, when using fstore to write data to flash, it is normal..

  May I ask what the problem is?What can I do about it?

[Vidar Berg]

Hi,

Are you able to check what the returned error from nrf_fstorage_write() is? Or do you get the error in your fstorage callback?

[summer]

hi ,When I erase flash using nrf_fstorage_erase, the err_code returned is 0x0000000,as shown in the following figure:

• When I turned on the debug  log, the log data was printed as follows:

• May I ask what I should do? thanks.

[Vidar Berg]

Hi,

Thanks for the log. The assertion is occurring in the app timer because you have run out of space in the app scheduler queue.  You may try to increase the size of 'SCHED_QUEUE_SIZE' to see if it helps. But keep in mind that flash erase operations take around 90 ms to complete, so you will eventually run out of queues if you repeat this operation every 8 ms. 

[summer]

Thank you very much. when I erase flash, I stop the timer and wait for the flash write to complete,and then turn on the timer,may I ask if this method is ok?  Is there a better way?

[Vidar Berg]

It will likely prevent the NRF_ERROR_NO_MEM error and should be ok as long as you do this infrequently. For more frequent flash operations I would recommend using the FDS filesystem on top because it leads to fewer page erases and provide basic wear leveling for flash. Note that the Absolute maximum ratings specify the flash endurance to 10 000 cycles.