Cannot read low current consumption on STOP2 mode with my STM32L412 board (~300uA+-), but using the same code and compatible with my STM32L476, i succeed (~3uA). ill be happy to work with low consumption with the STM32L412, can any one help me with that?

[Ypinh.1]

Hello guys, first, i would like to thank you about this forum i used a lot and got good suggestions and i learn a lot from you.

About my problem:

I checked a lot in the internet and see others that had the same problem like mine, but didnt find any with exactly same STM32L412.

anyway, i tried a lot of theirs and yours suggestions after they said what fixed their low power consumption problem in STOP2 mode.

the first thing i did is generate minimal code using the cubeMX for both the MCUs: STM32L476, STM32L412, that just configure the clocks, and enter STOP2 mode after small delay.

to improve the current consumption i did some of the suggestions i discovered in the internet with / without combination of them:

deinit all GPIOs before enter STOP2 mode.

using all the defined GPIOs as analog pull down

using all the defined GPIOs as analog no pull

using all the defined GPIOs as analog pull up

disable systick interrupt.

disabling HCLK,PCLK1,PCLK2,HSI CLK,MSI CLK

killing the debugger.

all of this i just tried with the output generated code from the cubeMX with minimal features - (only clocks).

to check the measurements i removed J26 and put DVM on current and the probs on the J26 exposed pins to short between them and let the code run in this way.

for the STM32L476 - It worked for me and i got good and expected results of current measurements in STOP2 (+-3uA)

for the STM32L412 - i got always results around (+- 300uA)

i read in the board datasheet about the jumpers in the backside and thought it may help but didn't find any one to remove or connect to fix it.

It feels for me that something with the STM32L412 hardware is the source of the problem, i hope i miss something.

Can you please help me with this issue?

Thanks, Yoni

[Andrew Neil]

You haven't said what board you are using?

[Ypinh.1]

Hello Andrew. thanks for reply.

i am using the board: NUCLEO-L412RB-P

and the board that is work for me: NUCLEO-L476RG

[Ypinh.1]

I succeed to solve the issue, i dont understand excactly why it works.

the solution was to move JP7 jumper to pins 2 and 3 instead of pins 1 and 2 that was set by default.

even not need to do that much in the code before entering stop2 mode and get current conusmption that arround 0.8uA to 5uA.

all the things i have tried to do before entering stop2 mode, decrease or increase the consumption in minory way.

so, it works, but it is not stable while im in stop2 mode.

instead of getting only 1uA i get sometime jumps between 0.8uA to 5uA.