Arduino for STM32

Thanks a lot.
I tried some of these things already before starting this thread.
It looks like my changed parameters in a local copy of SystemClock_Config(void), ie. RCC_SYSCLK_DIVx and other, are not having any effect.
That's why I asked for some expertise.

Sorry ag123, I don't get the point from your explanations. From my point a view it is not adressing the question using true lowpower states of the STM32F4x1 I have. Just using asm "wfi" doesn't help any, because real LowPower is a lot more than that. Al least that is my interpretation when...

@ag123: the tests using the sketch shown in the post is made only using the STM32F401 module (WeAct BlackPill). There are no peripherials that may consume any current. All pins of the STM32F4 are set to input, if they have been used, i.e. for the LED. I don't understand why ADC or I2C need to bee un...

The modules are powered through a MCP1702-33 which has an quiescent current of about 2uA. There is no difference in powering the STM32F401 in shutdown or deepsleep mode. If there would be a current from a voltage regulator, I expect it to be always there. But when having the STM32F401 in shutdown th...

Some additional information:
the power-led is removed from the BluePill, BlackPill module
the sketch has been modified so that the builtin-led is turned off when in sleep mode

Hi, I'm new to this forum and hope this question is at the right place. In an OpenSource project we are developing some hardware gathering data on beehives. These are lowpower systems so that they can run on battery for a long time. This works very well with STM32F103C8 (Blue Pill) or STM32F401 (Bla...