MEMS and sensors

I have a question about the ADC sensitivity for the vAFE in the ST1VAFE3BX. Table 3 of the datasheet says that the input range is +-25mV when the gain is set to 16. With a 12-bit reading, this results in about 12 uV/LSB of resolution. However, the "AH / vAFE channel gain" row of the table lists 1311 LSB/mV, or 0.76 uV/LSB of resolution and mentions "16 bits, input referred". These values seem to conflict. Is the sensitivity 0.76 uV/LSB or 12.2 uV/LSB? This is a huge difference in sensitivity. If 0.76 uV/LSB is achievable, what settings can be used to reach it? According to the datasheet, none of the configurations appear to generate samples with more than 14 bits. In my experience working with the part, the vAFE samples are always at least 14-bits when using vAFE only mode. When enabling the low-pass filter, I see 16-bits. This also doesn't seem to match the information in the datasheets or application notes, further increasing my confusion. I would very much appreciate any c

Hi ST team,We are encountering an intermittent issue while using the TOF L3 module in a mid-range distance measurement setup. Below are the details: TOF frame rate: 30ms. Readout rate: 50ms. Distance mode: Medium range.Issue Description: When a stable target is present within the TOF field of view, it measures correctly. However, if a hand is moved quickly back and forth between the TOF and the target, an error frame occasionally appears. This frame has:Distance status: 255Distance value: 8191mmThe following frame typically reports:Distance status: 12A valid distance value (matching the original target)Observations and Questions:All frames with status 255 appear on odd-numbered frames (i.e., those with smaller pulse intervals);These frames have abnormally high ambient light count rates (around 6x normal), even though the histogram data appears almost identical to normal frames;We suspect this high ambient count rate might be causing the signal to be discarded by the internal processing

Does the LSM6DSV support in-circuit firmware updates over SPI? If so, is there an app note that details how to do this. We are just trying to plan to support this in our new design if needed.

Hello Team,We are using the Qualcomm QCS6490 chip set running Android 13 on our custom board.As part of our project, we have integrated the LSM6DSOTR sensor, which is connected to the DSP pins via the I3C interface. Based on our discussion with the Qualcomm team, we understand that we need to update the JSON configuration files for the LSM6DSO sensor to reflect changes such as soc_id and bus_type.Although our sensor is part of the PVL, we understand that for all non-POR sensors, the OEM is expected to coordinate with the sensor vendor to obtain the following:SEE-compliant driver source codeJSON configuration file(s)Test results, including the Driver Acceptance Checklist validated with the same driver source and registry settingsTo proceed with the sensor bring-up, we kindly request the relevant JSON configuration files for the LSM6DSOTR sensor.Thanks,Ronak

Hi everyone,I'm working with the LSM303AGR magnetometer using an STM32 microcontroller and trying to run the built-in self-test as described in the datasheet. However, the self-test consistently fails — the delta values (normal vs self-test mode) fall outside the expected range.GoalPerform a successful magnetometer self-test and confirm the output is within the required limits (according to the datasheet).Summary of the IssueSelf-test bit is enabled in CFG_REG_C_M (0x62) → value reads back as 0x12.Data output seems valid and updates regularly.Delta between self-test and normal readings is either too small or too large, so the test fails.Self-Test Code (Full Function)void LSM303AGR_Mag_selfTest(void){uint8_t addr = LSM303_MAG_ADR, status;int16_t x_nost = 0, y_nost = 0, z_nost = 0;int16_t x_st = 0, y_st = 0, z_st = 0;int i; // Configure magnetometer: 50 Hz, continuous modelsm303AGR_Write8b_res(addr, 0x60, 0x8C); // Temp disable, low power, ODR = 100 Hz, continuous modelsm303AGR_Writ

Hi ST experts, Is there any linux driver library available for LIS2DTW12? Where can I find the related information/document? Thanks.

Hello,I was wondering if it is possible to set the steval-mki109d with steval-mki245KA to standalone.I would like to test the ISM330BX what is happening when rotating. Thus I have set up a kit with a battery pack and I can start up the measurement with MEMS studio 2.0. When I just pull out the USB-C connector, I think everything will go on (LEDs keep doing the same thing as when i turned the mems on in MEMS studio). But when I reconnect to MEMS studio the ISM330BX will have to be configured again. Meaning I cannot check the final values after rotating.Is there any way to for example log all the data to a SD card without writing all the code by myself? Or any other way to read out the final value without the processor/MEMS resetting?Thanks!

Hallo erveryone, I'd like to know if it's possible to use a VL53L8CX to distinguish between a human and an object and other non-living objects. I've done a little analysis of the data collected by the sensor, motion indication, distances, intensity of the signal measured. And I've come to the conclusion that a robust distinction between humans and other objects (animals or non-animated objects) isn't really possible with this sensor. My question at this level may therefore seem a bit ***, but would it be possible to make a reasonable distinction with this sensor, and have I perhaps ignored other details that need to be taken into account?  

Hi,do the STEVAL-MKI109V3 motherboard support STEVAL-MKI251A daughterboard or do I need the STEVAL-MKI109D Motherboard?STEVAL-MKI109V3 with FW 3.73.9 does not recognize STEVAL-MKI251A in my setup. Other daughterboards work just fine. /Ludvig

I am looking to extend battery life of the SensorTile.box PRO using sleep mode of STM32U5 and disabling the MEMS sensors. Currently I am measuring approx. 8 mA in this configuration, but I would like to reduce current into the uA range if possible.  I am running some quick tests in Arduino IDE using STM32duino libraries, but open to using Cube IDE as well:  LPS22DF.Disable();  LIS2MDL.Disable();  STTS22H.Disable();  LIS2DU12.Disable_X();   LSM6DSV16X.Disable_X();  LSM6DSV16X.Disable_G();  LowPower.deepSleep(1000); Could you help me understand the source of the 8mA current draw? What other devices do I need to configure into sleep mode? Are there any firmware examples which put the SensorTile in low power sleep? Thanks!

HI, this is Ahilesh Krishna, I am using STEVAL - MKBOXPRO module for my project, I am eager to know whether this module has in bag and out bag feature in it. Which means whether this would indicate whether the laptop is inside the bag or outside the bag. 

Hello,Could you please confirm that in LSM6DS, as in ASM330, as in ISM330, the low pass gyroscope filtering LPF2 cannot be bypassed and is only driven by ODR_G (no "enable" flag is available for this filtering stage) ?  Furthermore, the block diagrams in the corresponding datasheets suggest that a single ADC (ADC1) is used to digitize the three axes of the gyroscope. Could you please confirm that digitization is indeed multiplexed in these products ?Thank you by advance for your help.

Hello,I wish to test the IMU LSM6DSV, using STEVAL MKI239A and STEVAL-MKI109V3 Motherboard. In the past I've used Unico-GUI, where I could save to file not only inertial sensors' readings, but also temperature. Moving to MEMS Studio, I can no longer find a checkbox to select recording temperature values as well.Is there a hidden setting that allows that? I did find one can fix the temperature units in the GUI. that hints there might be an ability to read such data.Shmulik

Hi, I have STEVAL MKI109D, on it I mounted STEVAL MKI250KA. I would say if I could use QVAR Swipe Electrode mounted on STEVAL MKI250KA for reading Qvar signal. It is possible?

Hi, I have the STEVAL-MKI109D board, on which I mounted the STEVAL-MKI250KA. I would like to implement the free-fall example on the FSM, using data from the ST1VAFE3BX biosensor, using only MEMS Studio. Is it possible to do this without writing firmware solution? If so, how should I proceed? Thanks.  

Hi everybody. Please help me.  I bought a VL53L4ED sensor and would like to learn how to use it.I have found a number of documents and driver examples, but have been unable to find a document describing the internal registers and their function. (programming manual) . I must be looking for it wrong. Can you please direct me to the proper document?Thank you very much.  Jaroslav

I’m working with a LIS2MDL magnetometer sensor connected to an STM32F407VTG6 microcontroller running FreeRTOS. The sensor communicates over the SPI3 interface, and is configured to operate in SPI Mode 0 (CPOL=0, CPHA=0). The chip select (CS) pin is initialized to HIGH at startup using STM32CubeIDE.I’ve also attached the wiring diagram and SPI configuration settings from STM32CubeIDE for reference.In my FreeRTOS task, I enable SPI 4-wire mode, and I’m able to read the WHO_AM_I register successfully—it returns 0x40, confirming that SPI communication over SPI3 is working correctly.However, the DRDY (Data Ready) flag never goes high, so the sensor doesn't indicate that data is available. When I bypass the DRDY check and try reading the magnetic field values directly, I get invalid data:X = -1, Y = -1, Z = -1.This makes me think there may be an issue with the sensor configuration or the data reading process, but I haven’t been able to identify the root cause.Any help in troubleshooting this

Hello. I have recently made a custom PCB as a learning project and I have issues with getting data from the sensor. I have used multiple VL53L7CX Satel prebuilt breakout boards and those work fine with my software. I have used both the qwiic python library and the ULD driver on a raspberry pi which have worked fine, but when I use the same code for the custom PCB the sensor does not measure data.  When I use check_data_ready() which should turn true when data is available, it never returns true. I have also tried bypassing this and just reading the data, but i get an output of 8x8 zeros.    For simplicity, my code is just a small variation of the code at: https://github.com/sparkfun/qwiic_vl53l5cx_py/blob/master/examples/qwiic_vl53l5cx_ex6_settings.py (Just added my code for swapping to the correct MUX channel)   Are there any apparent problems with this that may cause it to not return data? Is there an initialization prossess I need to think about that is not

Hello everyone,I am using the LIS2MDL sensor in a parking project, where it operates via interrupt using a threshold value of 60. Initially, the sensor is calibrated with hard-iron correction and is able to detect interrupts properly. However, when a car approaches the sensor, the magnetic field, in all axis, changes significantly, causing the interrupt threshold to be exceeded.I want to recalibrate the sensor using hard-iron correction so that the X, Y, and Z axis readings return as close as possible to zero. This would allow the sensor to detect another interrupt after the car moves away. The problem is that the hard-iron correction function does not seem to work properly on its own. I’ve only been able to make it work by reinitializing the sensor and then applying the hard-iron calibration. I know this isn't the proper method, but I haven't found a better solution.Do you have any suggestions on how to handle this more effectively?I forgot to mention that I also tried disabling the i

Hi, I have an evaluation board STEVAL-MKI168V1 with the sensor IIS2DH. I was hoping to plug it into the DIL24 connector of the SensorTile.Box PRO and be able to see the sensor's output using the MEMS Studio. This does not seem to be the case. Can somebody provide me some guidance on how to access the sensor data using the SensorTile Box? Currently I am running the firmware FP-SNS-Datalog2 v 3.0.0. I saw that the Git repository https://github.com/STMicroelectronics/fp-sns-datalog2 includes drivers for the the sensor IIS2DH, so it looks like it should be possible to access the sensor somehow.  Thanks,Michal 

Hi ST Experts, I am working with the P-NUCLEO-53L8A1 evaluation kit and have followed the user guide to install the necessary software packages and GUI. I was able to detect the STLINK COM port connected to the evaluation board. However, after refreshing the list and attempting to flash the firmware, I repeatedly receive an error message and am unable to connect to the sensor successfully, despite multiple attempts.   Could you please advise what might be causing this issue with my board? Thank you. 

Hello, I am using the LIS2MDL development kit. I have two questions. When I measure with two development kits in the same environment, I get different values.Both are 5 cm away from each other and there is no factor that will disrupt the magnetic field around either of them.What could be the reason for this? When I bring a magnet closer to any of the development kits without changing its position and move it away, I get different measurements than the first values ​​it measured.For example:x: 500 y: 100 z: 800After moving the magnet closer and further away:x: 200 y: -200 z: 450When I reset the card nothing changes. It still reads the bad value. The position of the development kit does not change and I guarantee that the magnet is far enough away.What is the reason for this?  

I’m currently developing a vibration meter device and using the IIS3DWB accelerometer. I want to ensure that my acceleration data is as precise as possible. I’ve read that temperature can affect the accelerometer’s performance, so I’m looking for advice on how to compensate for temperature variations.

Hi, First of all, I'm not proficient with embedded C, but I would appreciate any input from you that I could feed to ChatGPT. I've been trying to have the codes generated, but they simply would not produce what I wanted. So I have a LIS3DH IMU connected to the ESP32 via I2C. I want to know if it is possible to have the ESP32 in deep sleep mode while waiting for the INT pins from the IMU to wake it up. INT1 should detect a shock of, say, 1.5 G-force, and INT2 for a tilt angle beyond a threshold. Since the ESP32 is asleep and not continuously polling the IMU, will this be possible? If so, can you provide hints on how to implement this?Secondly, I have connected an analog lux sensor to ADC3 of the IMU. I'm getting variations when probing it with a multimeter but it's not reflected on the raw ADC readings. I'm certain it's within the scale. Thank you very much.

LSM6DSV16X QVAR