BME688 and BSEC2 Library for STM32F4 in deep sleep mode

[ECall]

Hi,

I will use the BME688 sensor in combination to the BSEC2 library in a Cortex M4 STM32F401 MCU implementation. I want to retrieve the IAQ and sIAQ information from the system. As it is a battery powered device, I will use the Ultra Low Power mode for the BSEC2 + sensor implementation and the standby mode of the MCU where only 4kB of backup SRAM is maintened when the MCU sleeps.

I understand that to get relevant results, the system must retain the sensor config and some data to get the baseline for the IAQ accurate in time.

What data should I save in the backup SRAM when my MCU is in standby mode and can it be stored in less than 4kB ? Is it even possible to do that with the BSEC library ?

Thanks

[BSTRobin · Accepted solution]

Hi ECall,

The current software does not consider the loss of RAM in low-power mode, only for the situation that ram can be remained in low-power mode.
The minimum current is 2 uA for standby mode. What is the target current requirement? Can't stop with flash in deep power down mode(10 uA) meet your requirements?

[ECall]

Hi,

Indeed, as the sensor already draws 0.9 mA in LP mode, the difference between Stop and Standby mode in current consumption  for hte MCU is not much of an influence.

Thanks,

ECal