I2C Mapping for STM32H750B-DK

[Rafla]

I’m currently working on a project that involves I2C communication using the STM32H750B-DK  but I’m having trouble identifying which I2C peripheral (I2C1, I2C2, etc.) is connected to the Arduino I2C pins (SDA/SCL) on the board.

Unfortunately, I couldn’t find the schematic diagram of the board or any clear documentation that specifies this mapping.

[mƎALLEm]

Hello @Rafla and welcome to the ST community,

The documentation (user manual and the schematics) of the board is available on this link:

From the user manual of the board UM2488:

I2C1 is available on the Arduino connector CN2/ pins 9 and 10:

Refer also to this article on How to find STM32 board schematics.

Hope that answers your question.

[Rafla]

Hello,

Thank you for your detailed response and the information shared.

While working on the configuration using STM32CubeMX, I noticed that PD12 and PD13 are assigned to the I2C4 peripheral. However, according to the user manual and the ARDUINO connectors table (CN2), these pins are listed as I2C1_SCL and I2C1_SDA.

Could you please confirm if this configuration is correct? Is it normal that CubeMX assigns I2C4 to PD12/PD13 while the documentation refers to I2C1 for the same pins?

Additionally, could you kindly provide me with the official schematic of the STM32H750B-DK board or share the official link where I can download it? This would help me verify the exact I2C signal routing to the Arduino connectors.

Thank you very much for your support.

I found this link containing the schematic

https://fr.scribd.com/document/762570249/en-mb1381-h750xb-b01-schematic

[mƎALLEm]

Hello,

---

@Rafla wrote:

Additionally, could you kindly provide me with the official schematic of the STM32H750B-DK board or share the official link where I can download it? This would help me verify the exact I2C signal routing to the Arduino connectors.

---

I've already answered that question in my previous comment:

The documentation (user manual and the schematics) of the board is available on this link:

The schematics are available on "CAD Ressources" tab

Refer also to this article on How to find STM32 board schematics.

Now regarding your question about I2C1 or I2C4, and according to the the product datasheet, PD12 and PD13 has I2C4 function. No I2C1 on these pins. So I think it's a typo in the UM2488:

Also in the same user manual / figure 3 it sates that I2C4 is available on the Arduino connector:

I will escalate that for fix. (Internal ticket 206170)

[mƎALLEm · Accepted solution]

Hello,

According to the internal team we confirm it's an issue in the user manual so the I2C instance that is available on the Arduino connector is I2C4. Internal ticket number 206170 (not accessible by community users).

The document will be fixed.

[mƎALLEm]

Issue fixed in an internal version of the user manual, it will be available soon on the ST website. 

[Rafla]

Hello,

I read that the issue was resolved in an internal version of the user manual, and it will soon be available on the ST website. Could you please clarify whether I can use both I2C1  through the following pins: I2C1_SCL (PB6) and I2C1_SDA (PB7), as per the CubeMX configuration? I just want to confirm if this configuration is possible.

Thank you in advance!

[mƎALLEm]

In CubeMx you need to use I2C4:

[Rafla]

Can I use only I2C4 in CubeMX? I cannot use the other I2Cs even if I clear the pinout?

[mƎALLEm]

You cannot use other I2C instances in this board. Look at the CubeMx (the screen shot I've shared) they are marked in red because their IOs are reserved and used by other stuff on the board.