Current consumption using B-L072Z-LRWAN1

[Maxime DEWASMES]

Posted on March 26, 2018 at 16:28

Hi!

I'm curently using the B-L072Z-LRWAN1 (STM32L072 and LoRa board) with the STM32CubeExpansion_LRWAN_V1.1.4, and i'm trying to reduce the current consumption using this board.

I'm currently running into a high current draw from the power supply (when i'm forcing the board to get into stop mode at the first line possible in the main, i still draw over 3mA from the power supply)

I've tried to reduce the leakage from various ways (removed D2, no LED active, removed R19 to remove the link between battery and ST-link)

However i'm still unable to guess where does the extra mA are going...

At the start of my main, i'm using the insctruction HAL_PWR_EnterSLEEPMode(PWR_MAINREGULATOR_ON, PWR_SLEEPENTRY_WFI) (i've tried with stop and standby aswell, same current draw) and getting about 3.4mA at all time...During normal use, my current usage is about 25mA when transmitting and 13mA when receiving, not dropping below the 13mA (so I guess I'm not really entering sleep mode the correct way or I may have peripherals not correctly resetted prior to the sleep function call, but this is not my main concern at the moment as I will continue to try and debug this one)

If any of you got an idea, i'll be glad to give you any additionnal detail, i'm not quite sure what to link with this question (code, ...) so i'll add it if you need it, I don't want to spam the thread... yet !

Thanks for the help,

Have a nice day !

Maxime DEWASMES

#b-l072z-lrwan1

[Andrew Neil]

Posted on March 26, 2018 at 16:31

Always pays to use the 'Search' before posting - there have been a couple of threads on this

https://community.st.com/0D50X00009XkYNDSA3

https://community.st.com/0D50X00009XkbSOSAZ

Have you paid attention to the User Manual and removed all the connections described there for minimum consumption?

See the 'Related Content' at the foot of the page

[Maxime DEWASMES]

Posted on March 26, 2018 at 17:22

And i always do, I'm a bit reluctant to posting new threads on forums and always try a lot before giving up and asking for help...

I'm coming from the thread you've just mentionned, i've already applied everything I have found in these thread prior to posting this question

To try to sum up everything in a clearer way,

I have removed SB18 (led), D2 and added JP4 link and the R26 resistor as you and J Grandjean found out here

https://community.st.com/0D50X00009XkbSOSAZ

I've also tried to de-init everything as explained in the thread

https://community.st.com/0D50X00009XkYNDSA3

to the point i'm currently only trying to get into low power mode (i'm not doing anything else in my main at the moment, so no init of any other peripherals whatsoever)

I've also followed the ST recommendations regarding getting to low power in the user manual..

However with all these things done i'm getting 3.4mA out of my powersupply so that's the main reason I asked if I just missunderstood anything, and as the posts felt already solved I did not feel it was correct to reply there with my question

I'm trying my best re-re-redoing all the steps explained above to check if I didn't forget anything but so far it did not improve the behaviour of my board

[Maxime DEWASMES · Accepted solution]

Posted on April 10, 2018 at 13:57

I forgot to update about this issue:

I finally fixed that huge power consumption problem I had with the card, but it appears it was somehow related with the version STM32CubeExpansion_LRWAN_V1.1.4

After downloading the version 1.1.5 and putting all my code into it, the current draw went back to noticeably lower values.

I'm now getting values in the range of some uA which is better to work with!