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Associate II
September 18, 2025
Question

I2C and BLE on the STM32WB05

  • September 18, 2025
  • 2 replies
  • 239 views

Hi, all
I'm developing a BLE device using the STM32WB05 that supports I2C and BLE connections.

I successfully established an I2C connection using I2C_SCL(PB6) and I2C_SDA(PB7).
However, PB7 is used for RADIO_RF_ACTIVITY on BLE, causing a conflict between BLE and I2C.
Therefore, I tried changing to I2C_SCL(PA0) and I2C_SDA(PB14) to connect to the I2C master, but the connection failed.

I'm wondering if the I2C pins on the STM32WB0 are limited to only PB6 and PB7.

thanks.

This topic has been closed for replies.

2 replies

STTwo-32
ST Technical Moderator
September 18, 2025

Hello @nama 

According to the table 6, table 7 and table 8 of the DS14591,  I2C1_SDA and I2C_SCL are available on PA0, PB6 for I2C1_SDA and PA1, PB7 for I2C_SCL. The PB14 is used for I2C1_SMBA signal.

Best Regards.

STTwo-32

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Andrew Neil
Super User
September 18, 2025

@nama wrote:

I successfully established an I2C connection using I2C_SCL(PB6) and I2C_SDA(PB7).


So you're using I2C1, then:

AndrewNeil_2-1758197737859.png

 

 


@nama wrote:

I tried changing to I2C_SCL(PA0) and I2C_SDA(PB14) .


As @STTwo-32 said, There is no I2C_SDA on PB14:

AndrewNeil_0-1758197680456.png

You need PA0 and PA1:

AndrewNeil_1-1758197711066.png

 

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.