Pair device address and BT_Characteristic Notify enable disable use unwanted flash space in NCS v1.4.2

RE: Pair device address and BT_Characteristic Notify enable disable use unwanted flash space in NCS v1.4.2

Susheel Nuguru — Fri, 13 Aug 2021 12:20:44 GMT

You can use bt_unpair for that.

RE: Pair device address and BT_Characteristic Notify enable disable use unwanted flash space in NCS v1.4.2

Sunil vignesh — Wed, 11 Aug 2021 13:14:39 GMT

Susheel,

I will work out on this CCCD .

How to delete paired data permanently. the pairing data is controlled by softdevice itself isn't it.

RE: Pair device address and BT_Characteristic Notify enable disable use unwanted flash space in NCS v1.4.2

Susheel Nuguru — Wed, 11 Aug 2021 13:08:53 GMT

You cannot set it to enabled by default unless the devices are already bonded and the bonded device previously enabled the CCCD. Changing this behavior in gatt might need more changes than a one liner and I am not sure if it will be in compliance with the spec.

RE: Pair device address and BT_Characteristic Notify enable disable use unwanted flash space in NCS v1.4.2

Sunil vignesh — Wed, 11 Aug 2021 10:37:08 GMT

How to enable the required CCCD enable automatically from the device it is . means by default CCCD will be enable when the power is up or after ble connection established .

RE: Pair device address and BT_Characteristic Notify enable disable use unwanted flash space in NCS v1.4.2

Sunil vignesh — Wed, 11 Aug 2021 10:35:33 GMT

Sure, I will check this and update you shortly

RE: Pair device address and BT_Characteristic Notify enable disable use unwanted flash space in NCS v1.4.2

Susheel Nuguru — Wed, 11 Aug 2021 10:30:38 GMT

This is a custom requirement so you need to change the GATT behavior for it.

[quote user="Sunil vignesh"]is it possible to write only CCCD enable to flash storage ?[/quote]

You then need to change the gatt.c->bt_gatt_attr_write_ccc and change the below if condition

	/* Update cfg if don't match */
	if (cfg->value != ccc->value) {
		gatt_ccc_changed(attr, ccc);

#if defined(CONFIG_BT_SETTINGS_CCC_STORE_ON_WRITE)
		gatt_ccc_conn_enqueue(conn);
#endif
	}

to this

	/* Update cfg if don't match */
	if (cfg->value != ccc->value) {
		gatt_ccc_changed(attr, ccc);

#if defined(CONFIG_BT_SETTINGS_CCC_STORE_ON_WRITE)
    if (cfg->value)
		gatt_ccc_conn_enqueue(conn);
#endif
	}

Haven't tested, but i think it should work as you intend it.

RE: Pair device address and BT_Characteristic Notify enable disable use unwanted flash space in NCS v1.4.2

Sunil vignesh — Tue, 10 Aug 2021 13:00:02 GMT

Hi Susheel,

Have you check this

RE: Pair device address and BT_Characteristic Notify enable disable use unwanted flash space in NCS v1.4.2

Sunil vignesh — Mon, 09 Aug 2021 15:18:23 GMT

Yes, I found that using SMP the pairing data is written.

How to delete completely the pair data.

[quote userid="6207" url="~/f/nordic-q-a/78112/pair-device-address-and-bt_characteristic-notify-enable-disable-use-unwanted-flash-space-in-ncs-v1-4-2/324012#324012"]I found that some data is writing on the flash . Its like increase the size of the flash . i need to control the unwanted storage . how it is possible[/quote]

I found that CCCD CONFIG_BT_SETTINGS_CCC_STORE_ON_WRITE is enabled because when power cycle the device . its auto connect but not giving key report (ble_keyboard).

beacuse of enabling CONFIG_BT_SETTINGS_CCC_STORE_ON_WRITE it writes the CCCD enable and disable to flash storage.

is it possible to write only CCCD enable to flash storage ?

RE: Pair device address and BT_Characteristic Notify enable disable use unwanted flash space in NCS v1.4.2

Susheel Nuguru — Mon, 09 Aug 2021 12:48:37 GMT

Sunil,

Pairing data is written to the flash by controller as the SMP requests it. I do not know the internals of the size but most likely a page is reserved for this. I think it might be possible to increase the number of pages that the controller uses but might not be possible to remove it over all if you want bonding/pairing to work.

[quote user=""]I found that some data is writing on the flash . Its like increase the size of the flash . i need to control the unwanted storage . how it is possible[/quote]

It is possible for you to trace the calls back to the caller of the flash write functions if you put breakpoints to the flash API and start your application in debugger. For now, I do not have those internal details readily avaailable..

RE: Pair device address and BT_Characteristic Notify enable disable use unwanted flash space in NCS v1.4.2

Sunil vignesh — Fri, 06 Aug 2021 11:47:23 GMT

any update?

RE: Pair device address and BT_Characteristic Notify enable disable use unwanted flash space in NCS v1.4.2

Sunil vignesh — Tue, 03 Aug 2021 11:02:52 GMT

1. I want to use ble_hid_keyboard program. where i need to implement DFU and Flash storage to store some data

As i know from board management file the storage location starts at F8000 and size is 8000 if so. does DFU dual bank is working or not is any address collusion will occur or not i need to understand . and i have tested the NVS code in that data store is based on ID not direct address . and it use extra 8 byte each id while write / read also in delete . and it have restriction that one page complete and then it move to another page .

My requirement is

page size - 4096 bytes

allocate

1st page for bond management

2nd page for sensor1 data 1KB

3rd page for sensor 2 data 2KB

if i need i can delete the 2nd page and rewrite it . if i need to delete bond then i rewrite on 1st page

2. why those service enable function are stored in flash . i found these in ble_peripheral_uart and also in BAS service enable and disable function.

how to stop writing this in flash

3. Any example codes are there for direct address flash storage

if bond management is based on softdevice means how to control it . and function to delete the bond functionality

RE: Pair device address and BT_Characteristic Notify enable disable use unwanted flash space in NCS v1.4.2

Susheel Nuguru — Tue, 03 Aug 2021 10:30:25 GMT

Hi Sunil,

You are using a bit of an older version of NCS, read more on latest v1.6.1 (at the time of this writing)

[quote user=""]1. Pair device address is stored in what manner. I am not able to read and delete the pair data. Is there any document for bond management[/quote]

I am assuming that the bond management is done inside the Softdevice controller and no details about how it does that seems to be documented. What is your exact need for knowing this detail? What are you trying to achieve?

[quote user=""]I found that some data is writing on the flash . Its like increase the size of the flash . i need to control the unwanted storage . how it is possible[/quote]

You can easily understand this by setting the brearkpoints at the flash activity API and starting the program in debug mode. The function call stack will give you the contexts of those flash acitivity.

[quote user=""]3. I have use storage that to be start F8000 and size is 8000 . is it possible to write and read the data in page wise ( entering direct address to write and read data).[/quote]

It should possible to do that using the HAL drivers which are OS agnostic drivers. These HAL NVMC drivers use direct address to access flash but you should be very careful not to conflict you access with other modules in the RTOS system that think they own that flash page.