Example of low power consumption for B-L072Z-LRWAN1

[DuCanard]

Hello,
I use B-L072Z-LRWAN1 and I would like to know how to use it in very low power consumption. By default on mbed OS 6 with one hand with only one ThisThread::sleep_for(3s) I have a consumption of 10.45mA. I take my measurements with an amperemeter in series with the battery box. According to this post (https://community.st.com/t5/wireless-mcu/excess-current-consumption-running-b-l072z-lrwan1-from-battery/td-p/322961/page/2) to reduce my consumption I removed SB18, R26, D2. For the code I tried this code (https://github.com/janjongboom/stm32-standby-rtc-wakeup/blob/master/stm32_standby.h) which puts me at a consumption of 4.00mA. I'm new to MCUs and I'd like to know how I can reach the uA in the code or by another hardwre modification.
Thanks in advance for your reply 🙂

[Tesla DeLorean]

Sleeping only deals with the MCU. Expect to have to turn off Radio, TCXO, LEDs and anything else attached to the MCU that draws current.

Pull the circuit diagram / schematic, and walk-thru that.

[DuCanard]

I've looked into these possibilities
I have looked at the datasheet for the radio module ( https://www.mouser.com/catalog/specsheets/Murata_CMWX1ZZABZ-091.pdf ) and I have no idea how to put the lora card in standby mode.

As for the TCXO, I can't see where I can reduce its frequency.

I think I'm lacking knowledge in this area 🙂

[IIRHO.1]

Hello @DuCanard and welcome to ST Community.

I suggest you to take a look on this post i think it can be a good start for you.

When your question is answered, please close this topic by choosing "Accept as Solution". This will help other users find that answer faster.

Issam

[DuCanard]

Thank you @IIRHO.1 for your reply.
I followed the tutorial and removed the HAL_PWREx_EnableFlashPowerDown(); line, which must not be compatible with my card, and I get 3.4mA at best, which is better, but still a long way from microampere.