RAK3272 (Rak 3172) Board activate I2C in STM32CUBE Ide


i testet the RAK 1372 module with low level development reference!

Now i want to use a I2C-Bus für external sensors!

In stm32Cube IDE the Device Controll Center let me only activate I2C1 with the pins 10 and 9! (In schematic pins 10 and 9 connected to I2C2)

The I2C2 named on the board could not configured to the pins 10 and 9 !

When i save the configuration, there are some errors with lorawn radio module!
…/…/LoRaWAN/Target/radio_board_if.h:46:2: error: #error user to provide its board definitions

How can i use I2C in STM32 Cube IDE (1.7.0)?


Hi @Schulz ,

I think the best resource on that will be the STMicroelectronics. The I2C implementation on STM32Cube is created by them. We just provided the radio modification on the LoRaWAN middleware so you can use the RAK3172 on the STM32CubeIDE with reference/example.

Thank you for the answer. but i need to know the mapping from the schematic RAK3272 Board to the PIN-Definition of the STM32ELE5-Chip like the datasheet of STM https://www.st.com/resource/en/datasheet/stm32wle5jc.pdf (Page 49)

You only say Pin 9 and Pin 10 to I2C2, but this is not the designation of the chip connections!

I2C1 could be mapped to different pins of the Chip like PA9 and PA10!
The I2C2 could be mapped to PA12 and PA15!



You can find it in the datasheet under pin definitions

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Thank you! Thats want i want to know!