Unique Id stm32H7

[Osability]

Hello Everyone,

I am working on stm32h723zg, and I want to obtaind the serial of the micro controller for the unique id:

uint32_t unique_id[3];

void read_serial_number(void) {
// Unique ID registers

unique_id[0] = HAL_GetUIDw0(); // Unique ID Register 1
unique_id[1] = HAL_GetUIDw1(); // Unique ID Register 2
unique_id[2] = HAL_GetUIDw2();

}

How can I combine this id to obtain the proper serial number

[Peter BENSCH]

Welcome @Osability, to the community!

The Unique ID is a globally unique number consisting of 96 bits. As STM32 are based on Cortex-M, which in turn work on 32 bits, the individual 32-bit segments are read and can then be combined to form a 96-bit number. You can use this as a serial number.

Unfortunately, it is not possible to derive a (unique) serial number with a different length from these 96 bits, so in such a case you would have to define your own serial number and store it in the flash.

Hope that helps?

Regards
/Peter

[Andrew Neil]

Please see the Posting Tips for how to properly post source code:

https://community.st.com/t5/community-guidelines/how-to-write-your-question-to-maximize-your-chances-to-find-a/ta-p/575228

it should look like this:

uint32_t unique_id[3];

void read_serial_number(void) {
 // Unique ID registers
 unique_id[0] = HAL_GetUIDw0(); // Unique ID Register 1
 unique_id[1] = HAL_GetUIDw1(); // Unique ID Register 2
 unique_id[2] = HAL_GetUIDw2();
}

 

---

@Osability wrote:

How can I combine this id to obtain the proper serial number

---

What do you mean by, "proper serial number" ?

That code does give you the full 96 bits of the Unique ID in your unique_id array - what more do you want?

 

[Osability]

If you the microcontroller to a computer an open stm32cubeprogrammer , the serial number of the microcontroller shows, and this same number can be obtain using some python code. So I am asking if the serial number is a combination of the unique id of the microcontroller.

[Tesla DeLorean]

Do the hex digits look to match?

There's a different algorithm used for USB Serial Number, which I think creates a 64-bit 16-digit ASCII hex number. Look at the USB Device examples for that code to generate that descriptor.