STM32WB5MMGHx custom app couldn't go back to OTA Loader App

[Jtron.11]

I am following this video link showing step by step to create OTA app.

https://www.youtube.com/watch?v=mRzZOa3jmuM.

I am successfully to create the custom application, download the OTA loader app at 0x08000000, and the custom's app at 0x08007000. The problem I am facing is whenever I sent some data to OTA Reboot characteristic, the custom app is just reset, then go back to the custom app. It didn't enter the OTA loader app. Am I missing something like the erase current app function? I also notice in my custom app, once the ST BLE tool box or ST BLE Sensor app connects to my device, it didn't show the OTA reboot option like when I tried the BLE_p2pServer_ota.

[Jtron.11]

 

So I found this info,

When my device is up, it has the option "OTA Reboot Request" when I use ST Ble Toolbox,

I write Hex "000702" but nothing is happening

My code has

  case CUSTOM_STM_BOOT_REQUEST_EVT:

   *(uint32_t*)(SRAM1_BASE) = *(uint32_t*)pNotification->DataTransfered.pPayload;

   NVIC_SystemReset();

   break;

Do I understand the logic is OTA loader will use the information from SRAM1_BASE (which is define at 0x20000000UL, to erase my 2 sector starting at 0x08007000?

#define SRAM_BASE       (0x20000000UL)/*!< SRAM(up to 256 KB) base address */

#define SRAM1_BASE       SRAM_BASE         /*!< SRAM1(up to 192 KB) base address */

If I used the programmer, and manually erased 2 sectors starting from 0x08007000, after the power cycle, my device always comes up with STM_OTA which is the OTA loader application was loaded at 0x08000000.

Please suggest where should I need to double check or my errors.

[ALABR.1]

Hello @Jtron.1​ ,

Please not that I am not an expert of BLE or OTA, but from my own experience I could give you some advises. 

First of all, may I have for information about your configuration?

What MCU are you using, running on an EVAL board ? What binary OTA application do you flash ? It is the last release ?

For the following I am assuming that your are running an custom BLE application.

Here is the general idea of procedure for OTA application:

• {Ensure your BLE stack is update and running}
• Flash OTA application at @0x08000000
• Add OTA reboot characteristic to one of your BLE service
• Managed the OTA reboot characteristic

In custom_app.c:
...
 case CUSTOM_STM_OTA_REBOOT_REQUEST_WRITE_EVT:
 /* USER CODE BEGIN CUSTOM_STM_OTA_REBOOT_REQUEST_WRITE_EVT */
 	APP_DBG_MSG("\r\n\r** OTA Reboot event!\n");
 	/* Write reboot reason at 0x20000000 (SRAM1):
 	 * Boot Mode: 0x00-> User Application (0x08007000), 0x01-> OTA application (0x08000000)
 	 * Sector index: 0x07 (7 sectors is the first to be program)
 	 * Number of sector to be erase (4K granulation): Filesize/4K + 1
 	 * Total: 3bytes (octets).
 	 * */
 	*(uint32_t *)SRAM1_BASE = *(uint32_t*)pNotification->DataTransfered.pPayload;
 	NVIC_SystemReset();
 	while(1);
 /* USER CODE END CUSTOM_STM_OTA_REBOOT_REQUEST_WRITE_EVT */
 break;
...

• Managed the vector table relocation (or not?)

In /Core/Src/system_stm32wbxx.c
...
 
#define USER_VECT_TAB_ADDRESS
#if defined(USER_VECT_TAB_ADDRESS)
/*!< Uncomment this line for user vector table remap in Sram else user remap
 will be done in Flash. */
/* #define VECT_TAB_SRAM */
#if defined(VECT_TAB_SRAM)
#define VECT_TAB_BASE_ADDRESS SRAM1_BASE /*!< Vector Table base address field.
 This value must be a multiple of 0x200. */
#define VECT_TAB_OFFSET 0x00000000U /*!< Vector Table base offset field.
 This value must be a multiple of 0x200. */
#else
#define VECT_TAB_BASE_ADDRESS FLASH_BASE /*!< Vector Table base address field.
 This value must be a multiple of 0x200. */
#define VECT_TAB_OFFSET 0x00007000U /*!< Vector Table base offset field.
 This value must be a multiple of 0x200. */
#endif /* VECT_TAB_SRAM */
#endif /* USER_VECT_TAB_ADDRESS */

• Modify linkerscript (STM32WB5xx_FLASH.ld file) to add the magic keyword section

...
 .ota_region 0x08007140:
 {
	KEEP(*(TAG_OTA_START))
	. = ALIGN(4);
 } >FLASH
 
...
 
 .ota_region_end :
 {
	. = ALIGN(4);
	KEEP(*(TAG_OTA_END))
	. = ALIGN(4);
 } >FLASH
 
...

• In app_ble.c

/**
 * These are the two tags used to manage a power failure during OTA
 * The MagicKeywordAdress shall be mapped @0x140 from start of the binary image
 * The MagicKeywordvalue is checked in the ble_ota application
 */
PLACE_IN_SECTION("TAG_OTA_END") const uint32_t MagicKeywordValue = 0x94448A29 ;
PLACE_IN_SECTION("TAG_OTA_START") const uint32_t MagicKeywordAddress = (uint32_t)&MagicKeywordValue;

• Ensure your MagicKeyword is correctly written (using STM32CubeProgrammer for exemple)

You may see the OTA procedure describe in this figure

 

AN5247 may be usefull for you.

BeST Regards,

Axel L.

[Jtron.11]

Thank you Axel.

I found the bug. My copied and pasted code mistake so I used the Notification characteristic for the Reboot Mode characteristic which is the problem I will never got the command sent in from ST ToolBox BLE app.

[ALABR.1]

Glad that you resolve your problem.

May you flag this question as answer, this can help other people.

BeST Regards,

Axel L.

[Jtron.11]

Axel,

May I ask you couple questions regarding the ST BLE toolbox or Sensor app?

1. When I tested either with HeartRate_ota or P2P_Server_ota, the 2 app nicely provide more button and calculate the parameters in the background to send to the application to back to STM_OTA.

Is this proprietary from ST? Or there are any App Note that share the information.

Is the feature depending on the specific UUID it receives?

In my custom template app, I have 1 service: 2 characters: write and notification. Doesn't matter what UUID I assigned but when I used FULL 128 bits, my write characteristic always show the same UUID as the notification characteristic.

If I changed them back to reduce, I then see 2 different UUID (2 bytes) for each of characteristics.

Do you know why?

Or do you know any App Note to elaborate the UUIDs?

[ALABR.1]

Sure, if I can help,

From what I experience:

1. ST BLE Toolbox/sensor are develop by ST. I thinks that the app managed alone the command because the UUID is standard for OTA procedure so the app recognize it. I don't know well about theses two apps.
2. When creating services you have two options:
   1. Use standards UUID publied and reference by the SIG, so you can use the reduce for on 16-bits (for exemple Heart rate service is 0x180D). I attach for you a document that describe the standards UUID.
   2. Generate random UUID for you own custom services/caracteristics. Please not that is it mandatory to not use a standard service UUID for your custom services UUID. You can find online custom UUID generator.

[Jtron.11]

Thank you Axel,

That is my problem. I generate 128 bit of UUID for my own, I used it for Service, Write, and Notification characteristics but ST BLE tool box pickup and use the same UUID for Write and Notification. I don't understand this.

[ALABR.1]

Please pay attention that you need to generate a custom UUID for you #Service1 then generate customs UUIDs for you characteristic #CharA, and #CharB.

As a result of the previous example, you will have a custom service #Service1 that contain two characteristics: #CharA and #CharB.

[Jtron.11]

Thank you so much for your help. I might not clear in my previously post.

I generated for example EEAABB01-0000-0000.., I used for Service 1 then I just change EEAABB02- 0000-0000.., and EEAABB02-0000-0000.., for CharA and CharB respectively.

Still the ST BLE toolbox app pick only EEAABB02-0000-0000.., to show on the app for both Char.

[ALABR.1]

Let's said you have generated the following for your custom service:

F000AAAA-0452-4000-C000-000000000000.

Then for your 2 char you may change to:

F000BBBB-0452-4000-C000-000000000000 #CharA

F000CCCC-0452-4000-C000-000000000000 #CharB

Only the bits[16:32] change. Can you try this ?