How to determine how much current an MCU will draw?

[sky tree]

How do I calculate how much current the MCU will draw? Or can I find the IDD value in the datasheet?

[LCE]

There’s usually info in the datasheet under several conditions.

And then CubeMX has a tool for checking this, depending on the clocks, peripherals, ...

[AScha.3]

see ds:

 

[Ozone]

By measuring.

The datasheet will give a range and average numbers, depending on certain parameters like VDD, temperature, clock, and peripheral usage.

[Andrew Neil]

As already said, the datasheet gives figures on which to base an initial estimate.

Then you can measure with an actual device and actual code -  (most?) ST boards provide a test point for this very purpose.

Note that a multimeter is unlikely to give a useful reading, as the current will vary depending on what your code is doing.

There are many devices which are specifically designed for this kind of measurement; eg, from ST:

X-NUCLEO-LPM01A STM32 Power shield;

STLINK-V3PWR Debugger with power measurement

 

Many 3rd-party devices are also available.

 

PS:

For the ST tools, see also:

STM32CubeMonPwr Graphical tool displaying power data