BLE Advertisement does not update after reflashing

RE: BLE Advertisement does not update after reflashing

zazas321 — Thu, 07 Dec 2023 13:15:08 GMT

You are totally right. I had hts.c file in my project and that had an effect (even though no functions were called.

Not going to lie, this must be the dumbest thing I have seen in my programming experience. Just by having .c file in your project without any function calls there was a automatically a BLE service added. This person who wrote this code should be sent to prison.

Thank you for helping me out.

RE: BLE Advertisement does not update after reflashing

Turbo J — Thu, 07 Dec 2023 12:03:58 GMT

Look at the actual project files in the src folder, I bet there is a hts.c in there.

RE: BLE Advertisement does not update after reflashing

zazas321 — Thu, 07 Dec 2023 06:04:16 GMT

Are you referrng to this:

If yes, that did not do anything.

Experiment #2

To test if I can add new services, I have added the following to my code:

static const struct bt_data ad[] = {
	BT_DATA_BYTES(BT_DATA_FLAGS, (BT_LE_AD_GENERAL | BT_LE_AD_NO_BREDR)),
	BT_DATA_BYTES(BT_DATA_UUID16_ALL, BT_UUID_16_ENCODE(BT_UUID_BAS_VAL))};

and in my prj.conf I have enabled:

CONFIG_BT_BAS=y

After flashing the device and opening nRF Connect on my mobile phone, I see the new Battery Service appear but Health Thermometer still persists:

I have also tried on multiple phones and all phones provided same results.

The experiment above proves that:

nRF52 device is capable of adding new service (Just like I added Battery Service)
There is still no logical explanation on why the Health Thermometer service appears
The issue regarding Health Thermometer persists on different devices (multiple phones).

I am really hoping that we can get to the bottom of this as this is really frustrating.

RE: BLE Advertisement does not update after reflashing

Turbo J — Wed, 06 Dec 2023 21:32:15 GMT

I was wrong, HTS is actually its own source file in the example code (hts.c in src directory) and not activated via Kconfig nor device tree.

Double check that this file is not actually present in your code - it does not need any calls from main() to be active.

Some devices can cache device discovery data. NRF connect has a "Refresh services" menu option that should read service definitions fresh from the device.

RE: BLE Advertisement does not update after reflashing

zazas321 — Wed, 06 Dec 2023 19:27:30 GMT

I appreciate your suggestion and I will go through the course but that is not the point. I am interested in debugging this issue as I am convinced that this is a bug and there should not be HTS service in my simple BLE example code. I dont know whole lot about BLE but I know enough to understand that this is not how it supposed to work.

Instead of suggesting various things, why dont you take a minute to try this out yourself and you will recreate the issue and realize that this should not happen.

RE: BLE Advertisement does not update after reflashing

dejans — Wed, 06 Dec 2023 18:13:33 GMT

Hi,

Instead of stripping down existing project, you could potentially look at how to set advertising data in the BLE Fundamentals course.

Best regards,
Dejan

RE: BLE Advertisement does not update after reflashing

zazas321 — Wed, 06 Dec 2023 11:19:54 GMT

[quote userid="18935" url="~/f/nordic-q-a/106385/ble-advertisement-does-not-update-after-reflashing/459146"]The HTS service is probably included in the prj.conf. You might want to read the Zephyr documentation a little more, this RTOS has several configuration options (and files) that all apply to a project.[/quote]

I thought that initially as well. But I do not think that is the case. Check my prj.conf, it does not have anything to do with HTS. I have basic understanding of Zephyr RTOS and I am aware of configuration files.

See my prj.conf

My build configuration is as following:

Perhaps there is something strange going on here. Since I initially flashed the device with the peripheral_ht sample project (that definately had HTS service) and then I reflashed it with my own program, perhaps somehow the information got cached or saved somehow? Is that even a possibility?

I am hoping that someone can try to recreate the issue to ensure that I am not the only one.

Steps to reproduce:

1. flash the peripheral_ht sample project to nRF52840DK nRF52840

2. flash my program

3. Monitor services via nRF Connect app on the phone.

RE: BLE Advertisement does not update after reflashing

Turbo J — Wed, 06 Dec 2023 11:14:17 GMT

You can still use breakpoints to inspect variables and registers - but you cannot resume after stopping.

Otherwise use the LOG module.

The HTS service is probably included in the prj.conf. You might want to read the Zephyr documentation a little more, this RTOS has several configuration options (and files) that all apply to a project.

RE: BLE Advertisement does not update after reflashing

zazas321 — Wed, 06 Dec 2023 11:06:05 GMT

[quote userid="18935" url="~/f/nordic-q-a/106385/ble-advertisement-does-not-update-after-reflashing/459144"]Your screenshots show services after connection and service discovery[/quote]

Yeah your are probably right, I am probably not using the correct terminology here. I am still very new to BLE so apologies for that, but you understand what I meant?

In the screenshot, you see Health Thermometer primary service. How did that even get there since in my code I do not have anything related to Hearth Thermometer at all? I just simply have the most basic BLE peripheral example that I can do using Zephyr and that should not have any Health Thermometer services at all

Regarding the crash during the breakpoint - that makes sense. But in that case how would I debug the code if I have any problems since I cannot use breakpoints?

RE: BLE Advertisement does not update after reflashing

Turbo J — Wed, 06 Dec 2023 11:03:10 GMT

[quote userid="97527" url="~/f/nordic-q-a/106385/ble-advertisement-does-not-update-after-reflashing"]hat there are 3 services being advertised. [/quote]

Wrong usage of terminology here.

Your screenshots show services after connection and service discovery but not what is in the advertising packet(s). That is displayed in the nrf connect app in the "scanner" column that is to the left and thus invisible.

The softdevice/bluetooth stack checks if the app code could obey the stric bluetooth timings and faults whenever these are not met - especially if the CPU was halted in a breakpoint or in an interrupt handler that had too "high" priority (which is a low value in ARM NVIC).