BME 680: Minimizing power usage

[tbstoro]

Hi,

I´m working with the BME680 to measure air-quality, with a battery as the power source. To ensure a long lifetime of the device, I wish to decrease the power consumption beyond the ULP mode, accepting that this also will decrease the accuracy somehow.  Do you have any suggestions on what configuration I can set for this, such that it still will work with the IAQ calculations of the BSEC library?

I noticed that the heating time of the MOX layer was increased almost by a factor 10 when changing from LP to ULP, but when I manually tried to change the heater time, the IAQ was always returned as 0. The resistance seems to follow the same trend as for LP mode, so I assume this should still be possible?

[BSTRobin]

Hello tbstoro,

Could we know detailed information from you:
1.The link address of the software you use;
2.Software content you modified.

[tbstoro]

Hi! 

1. I use the software found in the BSEC 1.4.8.0, implementing the bsec_iot_example.c  with a microcontroller, and modifying the bsec_integration.c. 

2. The modification is simply manually changing the heater time and heater duration in the bsec_bme_settings_t struct, i.e. sensor_settings.heater_time = 200 in the bsec_iot_loop() before the loop starts.

Thank you for helping!

[BSTRobin]

Hello tbstoro,

You could see supported BSEC configurations from integration guide, implement this function config_load() which copy config file from config folder. By default, it used "generic_18v_300s_4d" configuration.

uint32_t config_load(uint8_t *config_buffer, uint32_t n_buffer)
{
// ...
// Load a library config from non-volatile memory, if available.
//
// Return zero if loading was unsuccessful or no config was available,
// otherwise return length of loaded config string.
// ...
return 0;
}