How many I2Cs are on the Seeed Lora E5 Mini board?

[markpow]

I asked this question on the Seeed community forum, and I decided to ask the same question here.

According to Viki, for this board, I have the following image:

This image shows two rows of pin labels: one grayed and the second colored. In my infrastructure, I use I2C3 with pin connections according to MX configuration from STM32CubeIde:

 

This connection configuration works for me for several sensors.

I tried to activate other I2C interfaces, but I didn't find a pair of pin connections that matched the MX views for all I2Cs.

So, my question is: can I activate other I2Cs besides I2C3 on this board?

 

[markpow]

I think this is the answer:

Looks like there is one possible I2C interface on this board.

[STTwo-32]

For the STM32WLE MCU, you can activate all available I2C interfaces of you don’t have any pin conflict. For the Lora E5 Mini board, it depends on the available on the module. So, for that, the définitive confirmation can only be provided by seeed studio.  

Best Regards.

STTwo-32

[Tesla DeLorean]

It depends significantly on what other clutter Seeed has added on their board, or via their "variant" file for Arduino or equivalent.

They have a bunch of resources tied to TX/RX, TX1,RX1 and TX2,TX2 that could probably be retasked/reassigned to I2C. PB6/PB7 could presumably be used as I2C1 in other universes..

The STM32 IC is going to follow whatever capabilities are expressed in the Data Sheet, covering various pin AF (Alternate Function) muxing options each pin has available.

https://www.st.com/resource/en/datasheet/stm32wle5jc.pdf#page=60

[Karl Yamashita]

All three I2C peripherals are available on the Lora E5(STM32WLE5JC) and go to the pcb header with different combinations of pins to use except for I2C2.

Now some of these pins may share with other peripherals like UART, ADC, SPI, etc.

So if you're using other peripherals, then you may be limited to which I2C instances you can use.

 

I2C1

SCL PA9/PB6
SDA PB7/PB9/PA10

 

I2C2

SCL PB15
SDA PA15

 

I2C3

SCL PB13/PC0/PB10
SDA PB4/PB14/PC1