I have implemented forced mode for a weather station like use case. But after a couple of measurements the I get the invalid measurements (-40°C, 100% humidity). The first couple of measurements seam to be fine.

Trouble shooting steps

• The sensor settings are written before every measurement to the sensor to roll out that the sensor settings get corrupted by interference or that the sensor gets reset due to flaky power

• I get the same behavior with to sensors

Version

• Driver Version: v3.5.1

Code

/*
Functions to test the bme280 temperature sensor with a config applicable for a weather station 
*/


#include "bme280_weather_station.h"


struct bme280_dev dev;
struct bme280_settings settings;
struct bme280_data comp_data;
uint32_t period;  // delay for measurement to complete
int8_t rslt;


void test_bme280_weather_station(){
    // Configure sensor for weather station mode
    rslt = bme280_configure();

    // program loop
    while (1) {
        // Re-apply settings to ensure oversampling isn't corrupted
        // uint8_t sel_settings = BME280_SEL_OSR_HUM | BME280_SEL_OSR_PRESS | BME280_SEL_OSR_TEMP | BME280_SEL_FILTER;
        // bme280_set_sensor_settings(sel_settings, &settings, &dev);
        
        rslt = bme280_set_sensor_mode(BME280_POWERMODE_FORCED, &dev);  // Trigger measurement
        dev.delay_us(period, dev.intf_ptr);
        bme280_get_measurement();
        display_temp(comp_data.temperature);

        wait_ms(100, true);    // Short delay for prototyping
    }

}


int8_t bme280_configure(){
    I2C_init();
    bme280_link_functions(&dev);
    rslt = bme280_init(&dev);

    // Configure Oversampling, filter and standby time (no effect in forced mode)
    rslt = bme280_get_sensor_settings(&settings, &dev);
    settings.osr_h = BME280_OVERSAMPLING_1X;
    settings.osr_p = BME280_OVERSAMPLING_1X;
    settings.osr_t = BME280_OVERSAMPLING_1X;
    settings.filter = BME280_FILTER_COEFF_OFF;
    // settings.standby_time = BME280_STANDBY_TIME_1000_MS;
    uint8_t sel_settings = BME280_SEL_OSR_HUM | BME280_SEL_OSR_PRESS | BME280_SEL_OSR_TEMP | BME280_SEL_FILTER;
    rslt = bme280_set_sensor_settings(sel_settings, &settings, &dev);

    // Calculate measurement delay
    rslt = bme280_cal_meas_delay(&period, &settings);

    return rslt;
}


int8_t bme280_get_measurement(){
    uint8_t status_reg;
    rslt = bme280_get_regs(BME280_REG_STATUS, &status_reg, 1, &dev);    // Get sensor status
    while (status_reg & BME280_STATUS_MEAS_DONE){
        rslt = bme280_get_regs(BME280_REG_STATUS, &status_reg, 1, &dev);    // Get sensor status
    };   // Wait if measurement is not done
    rslt = bme280_get_sensor_data(BME280_ALL, &comp_data, &dev);    // read measurement data
    return rslt;
}

How does BME AI Studio deal with this during training? Does it simply use the average gas resistance value from the two sensors? Are there some smarter ways to normalize the data?

Thank you.

I am trying to download the BSEC library for the BME690.

I completed the download/registration form on the Bosch Sensortec website and received the download link by email. However, when I click the link from the email, it redirects me back to the same registration form instead of providing the BSEC download.

Because of this, I cannot download the BSEC package.

Could you please check whether this is a temporary issue with the download portal or whether there is any additional approval/activation time required before the download becomes available?

My target is BME690 with STM32 Cortex M0+ the BSEC library for integration.

Thank you.

We are currently working on an air quality device based on the BMV080 sensor. During our testing, we observed that the sensor reports unusually low readings when a glass layer is placed in front of the sensor lens.

We would like to understand whether glass is the recommended protective material for this sensor, or whether there are alternative materials that should be considered. We are also seeking clarification on the theory or design considerations behind the selection of the cover material in front of the sensing area. Specifically, we would like to know whether the glass is intended only for mechanical protection of the lens, or whether its optical and material properties play a critical role in sensor performance.

As the datasheet provides limited information on this aspect, we would appreciate any guidance, recommendations, or design references you can share regarding suitable cover materials, placement considerations, and best practices for integrating the BMV080 sensor in an enclosure.

We would be grateful for your support in helping us understand and resolve this issue

We are using a VESC Controller 6/75 which has the BMI160 IMU implemented.

Usually the VESC is in a horizontal position and controls the pitch angle of the wheel side. We would like to use a vertical position, because the installation position would be advantageous for us. For that, we implemented a software coordinate transformation of the acceleration and gyro values. But the controlling of the pitch angle seems to be slightly less good and we are unsure, whats the root cause for that. We would like to eliminate the possibility, that it is caused by the vertical position of the IMU.

So here's my question:

Does the orientation (especially vertical) of the IMU affect the precision of the acceleration/gyro values? I couldn't find any information in the manual and i have a gut feeling, that it shouldn't affect the precision, but an experienced advice would be helpful.

Tanks in advance,

Enrico

Hi Bosch Sensortec Team,

I am working with the BMP390 pressure sensor in an embedded system and observing an unexpected drift behavior over time.

Observed behavior:

• After power-up, the sensor readings (pressure and derived altitude) remain stable for approximately 20 minutes.

• After this initial stable period, the pressure values begin to gradually increase/decrease over time.

• The drift is smooth and continuous (not abrupt or noisy).

• Raw values appear valid and consistent.

• Compensation is implemented according to the BMP390 datasheet.

Additional observations:

• The system remains in a stationary indoor environment during testing.

• Temperature readings show only minor variation and do not appear to correlate strongly with the drift.

• No I2C communication errors are observed during this period.

Configuration:

• Interface: I2C

• Sampling rate : 25 Hz

• Oversampling : Pressure x16, Temperature x2

• IIR filter : 4

• Power mode : Normal

Questions:

1. Is it expected for BMP390 readings to drift after an initial stabilization period, even when temperature variation is minimal?

2. Could this behavior be related to long-term thermal effects, internal compensation, or environmental pressure sensitivity?

3. Are there recommended configurations or filtering techniques to minimize such delayed drift?

4. Is there any known behavior or errata related to this kind of post-stabilization drift?

I have attached/logged pressure and temperature data over a duration of approximately 30–45 minutes.

Thanks and regards,
Abubakkar

I have downloaded BSEC 3.3, COINES SDK 2.12.1, BME AI Studio 3.2.0, and BME690 Dev Kit software 3.1.1.

Question 1:

I was able to get the flashing to work and currently have the BSEC_iot_example code running from the BSEC3.3. The screen output is shown below.

The issue here is that I want the sampling to be faster than the 300s default, but I am unable to get that working, hence the error at the top of the serial terminal with initlizing BSEC library error code 14. This happened when I tried to replace the bsec.selectivity.c and .h files under C:\Downloads\bsec_v3-3-0-0\examples\BME690\src\config. with the files I found in C:\Downloads\bsec_v3-3-0-0\release_bin\Sel_IAQ\config\bme690.

What am I doing wrong here?

Question 2:

The main goal is to change the bsec_iot_example.c file so that I can create a quick function to tell the user that something is affecting the IAQ reading that the sensor is detecting. Is there any guide to properly use the variables and code a program to do what I am trying to acheive? The integration guide in BSEC3.3 isn't super helpful as I am still learning how to do these projects. Any help would be appreciated.

Thank a lot for any hint.