STM32: consumption due to I2C in stop2 mode

[LLr.1]

Hi,

I use the nucleoWL (STM32WL which is based on STM32L4). I want to use LPWAN to communicate some measurements each day. I use I2C between MCU and sensors. If I try the Sigfox Push Button exemple, I have 2uA in stop2 mode but if I add I2C1 (thanks to cubeMX) (with any sensor yet) I have around 500uA in stop2 mode: That is too high...

I think that is due to internal pull-up resistors. Is it true ?

How to avoid this in stop2 mode ?

In the I2C_WakeUpFromStop2 example : the current drawn my the uC is around 1uA that is good for me. I think the pins are not pull up internally

I don't need a non-blocking mode for I2C communication because it's only one time per day, polling mode can be ok but I need a low consumption in stop2 mode. I will disconnect sensors during stop2 mode to avoid the sleep current of the sensors and the current in the external pull-up resistors.

How to do it in the Sigfox Push button exemple (for example) ? (do it = achieve a low consumption in stop2 with I2C pins empty)

Thank you

Best regards

[LLr.1]

NB: the I2C pins have to be no pull according to the Init done in CubeMX:

[Louis AUDOLY]

Hello @LLr.1​ ,

Sorry for the late reply, have you acheive to solve this issue ?

It seems that the GPIO needs to be pulled up. I tested the Sigfox Push Button project and I noticed a drop of 500uA by setting the GPIO in pull up mode rather in no pull mode.

Let me know is this were your issue or if you solved it already.

Best regards