Flash Write in BLE event

[BEN_HB]

Hi.

I saw lots of questions but I could't find answer about BLE & flash write func.

Setup is nrf52832, S332, SDK 15.3.0.

using ble, ant+, gpio, timer, adc,

in code, I try to flash write UICR 4bytes in ble event.

flash write func is execute when received op code from ble custom service write func.

I got it the issue is context switch.

I debugged and issue is nrf_fstorage_sys_evt_handler is not triggerd  in nrf_fstorage_sd.c

I wait long time however, the func is not execute.

I stop that and I check flash memory, the value is already write.

now temporarily use delay 5ms.

5ms is enough wirte 4byte in flash i think.

it does not ensure it is write.

I thought that use callback or other event handler, escape ble event, and try flash write.

otherwise, I don't know how to do it.

Thank you.

[Edvin]

Hello,

I thought that use callback or other event handler, escape ble event, and try flash write.

 That sounds like a good plan.

Maybe you call the flash write function inside a BLE event? If so, try to set a flag, and call the flash write in the main context (from your main-loop). That should allow for the flash operation to start, something it wouldn't if you try to call it from the BLE event handler. 

Then remember to wait for the flash event handler before you try to read the flash again, to ensure that the write is complete before you try to read it. 

I would recommend to use the FDS library.

Are you sure you want to write the data to the UICR area? Is there any particular reason for this? I believe this has restricted access while the softdevice is running. In addition, it is not that easy to update the value you store here. It is intended to only write to once, and then leave it for the lifetime of the product. That is why you should use the "normal" flash, which it will use if you use FDS.

Best regards,

Edvin

[BEN_HB]

Thank you. I write only once in uicr. and then execute just read.

I change wirte func in main loop. it is works.