A Problem on Buttonless DFU + Bonding valid.

[cw-park]

Currently, we are testing that 「buttonless DFU + Bonding valid」 in our App.

But After performing F / W Update with DFU, other BLE Service became invisible.(※2)

So, as a result of comparing the log of the Normal Project(No problem) with the log of the current problem project,

I found that there are the following differences.(In the normal case, the following events will occur.)

· PM_EVT_SERVICE_CHANGED_IND_CONFIRMED
· PM_EVT_PEER_DATA_UPDATE_SUCCEEDED

And Compared & checked "sdk_config.h", "makefile", "linkscript file", "source file", etc. But did not find a place likely to be a cause.

How can I solve this problem?

Why does the above log difference occur?

Please answer me about my question.

※ SDK Version

     nRF5_SDK_15.0.0_a53641a

※ IC

     nRF52832

※ Problem Project'SDK Config File

sdk_config.h

(※2)

<Before DFU Update>

     

<After DFU Update>

[cw-park]

・「Did you do bonding  in your application and in your DFU bootloader ? If you do bonding, have you set NRF_DFU_BLE_BUTTONLESS_SUPPORTS_BONDS = 1  ? and use ble_dfu_bonded.c in your application code ?」

Yes, of cource.No Problem.

For Application,

#define BLE_DFU_ENABLED 1

#define NRF_DFU_BLE_BUTTONLESS_SUPPORTS_BONDS 1

#define NRF_SDH_BLE_SERVICE_CHANGED 1

I am defining it.

In the case of DFU,

#define NRF_BL_DFU_ENTER_METHOD_BUTTONLESS 1

#define NRF_DFU_BLE_REQUIRES_BONDS 1

#define NRF_SDH_BLE_SERVICE_CHANGED 1

I am defining it.

・「The line you commented out checking if the service changed flag has been set or not. If it has been set, gatt_cache_manager.c will send a service changed indication to the iPhone and the iPhone will do a service discovery. By removing that check, you always request the phone to do service discovery, resulting in the full att table read by iPhone. 

To get the flag set, you would need to call gscm_local_database_has_changed(). This is done inside ble_dfu_buttonless_bootloader_start_prepare(), if you set the NRF_DFU_BLE_BUTTONLESS_SUPPORTS_BONDS  flag correctly, it should be called before you switch to the bootloader. 」

Yes, I already understand the above content.

I also confirmed the contents of "ble_dfu_buttonless_bootloader_start_prepare ()".

・「Note that you need to make sure the flash is being updated properly before you switch to bootloader. 」

Yes, I do not think that writing to Flash eventually went well.
However, as in the log of (★) below, Write to Flash was also Success.

In the end, despite successfully writing to Flash correctly,
Why does this problem occur?

========================LOG==================================
0> <info> app: Writing peer data to the bootloader...
0> <info> app: system attribute table len: 8
0> <info> app: In ble_dfu_buttonless_bootloader_start_prepare
0> <info> app: Device is preparing to enter bootloader mode.
0> <info> app: Disconnected peer
0> <info> app: peers_count 1
0> <info> app: peer id 0
0> <info> app: PM_EVT_PEER_DATA_UPDATE_SUCCEEDED
0> <info> app: Updating Service Changed indication for peers, 0 left
0> <info> app: Finished updating Service Changed indication for peers     <------★
0> <info> app: Device will enter bootloader mode.
0> <info> app: Start....
0> <info> app: gpiote_init
0> <info> app: button_init
0> <info> app: initADPD153GGRI

[Hung Bui]

You may need to dig deeper, and check on the first time booting up,after a DFU, would the new firmware be able to read the peer information data and get p_service_changed_pending = 1  ? or not. Maybe you put a break point in right after this printed out: Finished updating Service Changed indication for peers  , and check in flash if the data is written correctly. (you can simply dump the flash content to a hex and compare 2 hexes, before and after you trigger Start DFU) 

You mentioned that you didn't have trouble when testing with the buttonless example ? 

I assume you don't change attribute table or anything, simply DFU update the same firmware ?

 

[cw-park]

Hi Hung Bui.

・「You may need to dig deeper, and check on the first time booting up,after a DFU, would the new firmware be able to read the peer information data and get p_service_changed_pending = 1  ? or not. 」

-->I Checked. it was p_service_changed_pending  = 0. 

・「Maybe you put a break point in right after this printed out: Finished updating Service Changed indication for peers  , and check in flash if the data is written correctly. (you can simply dump the flash content to a hex and compare 2 hexes, before and after you trigger Start DFU) 」

--> I did. But When comparing HEX Dump,Because i do not know the storage address (because it saved the data with pdb_raw_store), I could not identify the location of p_service_changed_pending.

・「I assume you don't change attribute table」

--> Thank you. I looked at this part. 

After all, the cause was the definition of "NRF_SDH_BLE_GATT_MAX_MTU_SIZE".

To increase the transfer speed, set the MTU size to I changed it from 23 to 247.

When I restored it(247 -> 23),
· PM_EVT_SERVICE_CHANGED_IND_CONFIRMED
· PM_EVT_PEER_DATA_UPDATE_SUCCEEDED
An event occurred. it's OK.

By the way, I have the following questions so please check.
1) First of all, why does this part cause this problem phenomenon?

2) Next, in order to increase the transfer speed, I would like to maintain the MTU size as 247,
How can I deal with it?

[Hung Bui]

Hi Chan, 

 

Thanks for updating us. 

Could you confirm if you modify the buttonless dfu example in the SDK to have MTU size to 247, you see the same problem ? 

If you can check that, we can reproduce the issue here and find out what could be the wrong. Which phone did you use ? 

[cw-park]

Hi Hung.

・「Could you confirm if you modify the buttonless dfu example in the SDK to have MTU size to 247, you see the same problem ? if you can check that, we can reproduce the issue here and find out what could be the wrong.」

--> I tested. Also in the buttonless dfu example, if you change the MTU size to 247, this problem occurs.
I hope you test it out.

Since the problem is reproducible, please let us know which part is the problem.

※Which phone did you use ? 

    I used iPhone X.