MEMS (sensors)

Hi,My company uses the ASM330LHH for dead-reckoning applications and we are trying to improve the performace of the gyro with our own calibration of rotation sensitivity. After calibration, we want the gyro sensitivity accuracy to be 0.1 % or better over -20 to 70 C. I know this may not be easy or feasible, but we still want to get as close as possible. Our current calibration procedure uses an Ideal Aerosmith rate table that we try to set to 100 dps +/- 0.01 %, but we're running into a ton of issues getting an accurate enough speed. I'm hoping someone can help show us a better way!Right now, our rate table often misses the set rate by much more than 0.01 % or the rate will oscillate around the set point by much more than 0.01 %. We have tried using the rotation rate readout of the rate table, but that is showing its own set of difficulties. Is this what folks normally do for high-accuracy sensitivity calibration? Or is an ultra-high accuracy gyro normally used as

Hi,We're using the lsm6dsv's SFLP algorithm to calculate IMU rotation. Recently however we noticed that the resulting rotation has big gaps at around the 180degree mark. We believe this is because of the half float precision, specifically because there aren't a lot of representable values near 1. See below image for our calculated accuracy results which match the actual results we're seeing:  

I am using a python script to update the One Point Calibaration register 1Ah, 1Bh. I put values in but the resultant reading of the normal pressure registers in 28h, 29h, 2Ah are way off. Does anyone have a script that might show exactly how it is done. The script can be in about any computer langauge.Are there any tricks to get this to work?

Hi, I’m working with the IIS3DWB accelerometer to acquire single-axis data (Z-axis) using the following setup:Full Scale: ±16gSPI Mode 3 at 10 MHzTarget ODR: 26,667 HzI have attempted different methods to read the Z-axis data. First, I tried reading the Z-axis high (0x2D) and low (0x2C) registers using a timer with auto-increment. I also tried using 1AX_TO_3REGOUT mode and reading all 6 registers (0x28 to 0x2D) using a timer with auto-increment.I then configured the sensor with the following register settings:write_register(IIS3DWB_CTRL1_XL, 0x00); // Power Downwrite_register(IIS3DWB_CTRL6_C, 0x03); // Single Axis Mode (Z-Axis)write_register(IIS3DWB_CTRL1_XL, 0xA4); // Power On, Full Scale 16g, 26.667 kHz ODR write_register(IIS3DWB_CTRL3_C, 0x44);

Hello awsome peaple of the ST fourms,I've been writing a program on the MB1551-U585AI1-D01 STM32U5 dev board, after getting DMA working and writing some AzureRTOS aware platform functions for the MEMS sensors on the board I have been very successful in communicating with both the ISM330DHCX (IMU) and IIS2MDCTR (Magnetometer).However, I have a single issuse that has just popped up that has me puzzeld. During setup of the ISM330DHCX I first check the WHO_AM_I to make sure the sensor is present and talking, I then attempt to software reset it.  // Initialize IMU stmdev_ctx_t imu_dev_ctx; imu_dev_ctx.write_reg = imu_platform_write; imu_dev_ctx.read_reg = imu_platform_read; imu_dev_ctx.handle = NULL; uint8_t whoamI, rst; ism330dhcx_device_id_get(&imu_dev_ctx, &whoamI); if (whoamI != ISM330DHCX_ID) { //TODO: Handle device not found tx_thread_suspend(&imu_thread_ptr); } // Reset the dev

Hello community, I am an electronics engineer at the CNRS in Montpellier (France). I am currently working with the IIS3DWB vibration sensor When I use the LFP2 low-pass filter, the action of gravity is added to the measurements. I use the following data registers:- CTRL1_XL- CTRL3_XL- CTRL8_XL This result is as unexpected as it is disconcerting.Has anyone ever encountered this type of problem?Thanks in advance to anyone who can help me. Olivier Maudens    

Hello all,I am working with the LSM6DSV16X and trying to determine whether the Sensor Fusion Low Power (SFLP) algorithm processes raw or filtered accelerometer and gyroscope data. Specifically, can I adjust filtering settings (e.g., LPF2 bandwidth) before the data is used by SFLP?What I Have ReviewedI’ve checked both the LSM6DSV16X datasheet and Application Note AN5763, but I haven’t found a clear answer.The Sensor Fusion section only says it generates "the following data based on the accelerometer and gyroscope data processing," but doesn't specify which accelerometer and gyroscope data it uses.Figure 3 in AN5763 (Accelerometer filtering chain - UI pa

@SimonePradolini Hi Simone,Can I get a 64 Bit version of libhs_datalog.so for Raspberry Pi 5 of the X-CUBE-MEMSMIC1 expansion software package please?Or the source code to compile it?Unfortunately DATALOG_V1.5.1 just provides a 32 Bit version libhs_datalog_rpi3b.so for Raspberry Pi 3B only.This would be awesome. Best regardsJoerg

I have bought a MKI-165V1 to test LPS25HBTR,but I find that the pressure value is decreasing for a long time ,from 1014.117 to 1002.970 in an hour.It is not stable,the next is my initial code,what is the reason for ituint8_t data = 0x90;HAL_I2C_Mem_Write(&hi2c4, 0xB8, 0x20 , I2C_MEMADD_SIZE_8BIT, &data, 1, HAL_MAX_DELAY);HAL_Delay(10);data = 0x00;HAL_I2C_Mem_Write(&hi2c4, 0xB8, 0x21 , I2C_MEMADD_SIZE_8BIT, &data, 1, HAL_MAX_DELAY);// HAL_Delay(10);// HAL_I2C_Mem_Write(&hi2c4, 0xB8, 0x22 , I2C_MEMADD_SIZE_8BIT, pData, Size, 0xFF);HAL_Delay(10);HAL_I2C_Mem_Write(&hi2c4, 0xB8, 0x23 , I2C_MEMADD_SIZE_8BIT, &data, 1, HAL_MAX_DELAY);HAL_Delay(10);

Hello, Our teams is making a proof of concept about dead reckoning using a STM WESU board. The goal is to get pedestrian position onyl using ACC/GYR/MAG for a short period of time and small moves.First results in certains conditions are pretty good. Without any calibration/correction, we manage to get approx 3m absolute error on a 20m walk (30seconds). We expect same error on a 100m walk with good AHRS algorithm parameters and sensor calibration.We are ready to put more effort on the IMU. Do you have calibration source code/protocol for WESU sensor ? * LSM6DS3 = acc value + gyro drift* LIS3MDL = soft and hard iron calibrationWe also have other more advanced IMU, but we want to keep it simple and low cost for now and WESU allow us to be pretty fast on POC steps.Thanks a lot for your future help. Best regards. 

Hi ThereWhere I can find some source files for LSM303DLHCI see some ref.links there, but right now they pointed to non-existed pages on github :( Or I miss somethingAlso I found this link https://github.com/STMicroelectronics/stm32-lsm303dlhc but it contain some "Common/accelero.h" and I also can't find it on github :(Regards, Evgenij

Dear ST/Forum,Your attention would be much appreciated for a technical enquiry.We are using the LPS22HB pressure and temperature sensors in some electronics for an experiment that will be onboard the International Space Station (ISS) in orbit later this year. We are having great success reading the sensors generally but we have an anomaly in the data if you could please advise. Our code is communicating with your chip in one-shot mode using the chip enable line and SPI serial bus. We are powering the devices from 3.3V and the code enables the chip, waits 100mS and then begins reading.We are finding that the first pressure value and subsequent values all seem OK. However the first temperature reading is consistently 1 degree lower than all subsequent readings. This is consistent on one device and the same on all devices. Are you aware that the first temperature reading is known to be in error, or are we doing something wrong?Please see the plot file from t

Hello,I am working on a project using the LIS2MDL magnetometer sensor to build a smart parking device that detects the presence of a car based on the x-axis readings exceeding an interrupt threshold.Currently, I face an issue with setting high and low thresholds for the interrupt. For example, if I set the high threshold to +30 and the low threshold to -30, and the x-axis reading is around 1400 mG, the interrupt remains consistently high. This makes it difficult to reset and detect new threshold crossings.Is it possible to dynamically adjust the thresholds based on the initial raw data reading from the x-axis? For instance, could I configure the device to read the raw x-axis value during initialization and then set the high threshold to x_axis_val + 100 and the low threshold to x_axis_val - 100?I’d appreciate any guidance or suggestions.

Hi, We are developing a product/device that is mounted on a machine/vehicle that generates vibrations when in the ON state. We need a sensor that can 1.. Detect vibration start and stop while the device is stationary, with good accuracy, to determine when the machine is ON and for how long.2. Differentiate between vibration and actual motion, meaning it should detect when the device is no longer stationary and has started moving in any direction in on condition with vibration.3. Detect motion in the OFF state, where the machine is off (no vibration), but the device itself has started moving and trigger an interrupt to alert the MCU. Note: We can measure and predefine the acceleration threshold that should be considered as vibration. Is there a sensor with an internal mechanism that can directly provide output to differentiate between vibration and motion? Thanks, 

Hi, I'm trying to implement the tap and double-tap function in the FSM tab. Is it possible to achieve this at an output data rate of 26 Hz? 

We are using the X-STM32MP-GNSS2 (with the STM32 discovery board DK2), which has ISM330DHCX IMU. The accelerometer readings seem fine from the IMU, but the gyroscope gives enormously high and varying readings even when we are stationary. See below the varying output from the gyro  root@FAFUSION:/sys/bus/iio/devices/iio:device2# ls buffer in_anglvel_x_raw sampling_frequency buffer0 in_anglvel_y_raw sampling_frequency_available current_timestamp_clock in_anglvel_z_raw scan_elements dev name subsystem in_anglvel_scale of_node uevent in_anglvel_scale_available power waiting_for_supplier root@FAFUSION:/sys/bus/iio/devices/iio:device2# cat name ism330dhcx_gyro root@FAFUSION:/sys/bus/iio/devices/iio:device2# cat sampling_frequency 833.000000 root@FAFUSION:/sys/bus/iio/devices/iio:device2# cat in_anglvel_scale 0.000152716 root@FAFUSION:/sys/bus/iio/devices/iio:device2# cat in_anglvel_x_raw in_anglvel _y_raw in_anglvel

Hi all!I've recently started working on a fault classification model utilizing the proteus1 board and the NEAI studio suite. I'd ideally like to set up a serial datalogger via the onboard micro USB to both obtain and display readings, alongside benchmarking models. Connecting the proteus with the datalogger flashed via FUOTA (As I don't have a STLINK V3MINIE on hand) leads to it not being recognized when trying to select a COM port to obtain readings. I'd be grateful if anyone would be kind enough to tell me if I'm missing anything, or if there are specific COM drivers for this. Thanks in advance

Hello, I'm currently working on ST1VAFE6ax sensor to read 6 axis data from accelerometer and gyrometer via SPI protocol. But sensor is not behaving as expected. it returns the value as 0. Is there any initial booting process for the sensor or is anything I have to do for the sensor initialization? Pins assigned in my controller (STM32WB series) for SPI are behaving as expected. I have verified that pins with DSO. But the Slave out pin is not returning anything. How to solve it? I'm also having the user manual for the sensor. But I cannot resolve this issue. Please suggest me any solution if you have. Thanks in advance !

Hello community ,I am going to do 9 axis sensor fusion (6axis accel and gyro + 3axis magnetometer) and got across to the MEMs-Studio suite. I've bought STEVAL-MKI109D for motherboard and STEVAL-MKI217V1 as the shield. STEVAL-MKI109V3 is out of stock at that time.I pluged the USB for STEVAL-MKI109D with mounted STEVAL-MKI217V1, but the STEVAL-MKI217V1 isn't recognised but was recognised as STEVAL-MKI197V1 instead. The features of 6axis are fine but I need to test the 3axis mag also. Here are my software setting.STEVAL-MKI109D firmware was updated to v 0.8.14MEMs Studio  1.4.2

We embed LIS3MDLTR on our board that we produce, because this has high sensitivity: 6842 LSB/gauss. This corresponds to 0.146 mgauss/LSB, if I convert correctly. The other products has significanltly lower sensitivity: 1.5 mgauss/LSB. What are you proposing to replace the LIS3MDLTR once it is discontinued?https://www.mouser.com/PCN/STMicroelectronics_15054_1.pdfRegards

Dear ST/Forum,We are using the LPS22HBTR pressure-temperature sensor in some PCB assemblies.Due to some cleanliness requirements of the experiment, I need to be able to clean the PCB this device is attached to but due to the very fine holes in the lid to allow pressure to be measured, and your warnings in data to "not clean in solvent" etc, we are after some advice. I have purchased some liquid masking compound used in electronics assembly and propose to paint this onto the top of the device before cleaning and then peel it off after cleaning. Have you seen this done before and is it likely to cause a problem? I would prefer not to break a device trying this as replacing them on PCBs is difficult due to the geometry.The masking compound is called Techspray WonderMASK P, Peelable Solder Mask Product# 2211. Data attachedThanks in advanceDuncan

Thank you for solving my problem. Please forgive my poor English.I am using lsm6dsl sensor. When I use FIFO to read LSM6DSL, the data is correct at the beginning, but later there will be data errors. configuration :XL_ODR_208HzGY_ODR_208HzFIFO_208Hz2g, 2000dpsXL_ANA_BW_400HzLOW_NOISE_LP_ODR_DIV_100BDU EnableAfter my machine is turned on, I will run lsm6dsl_freq_reset first to ensure that my LSM6DSL is at 208Hz, but I will not turn on the FIFO. I will execute lsm6dsl_fifo_set through the serial port to turn on the FIFO. You can refer to the file I uploaded      #define PATTERN_LEN ((3 + 3 + 3) * 2) #define LSM_DATA_PACKAGE_NUM (10) void lsm6dsl_fifo_set(void) { uint8_t temp = 0xAA; lsm6dsl_int1_route_t int_1_reg;

Are there any plans to have a video tutorial on the biosensor eval board?  (ST1VAFE3BX)? I connected it to MEMS Studio via the MKI109V3.  I'm experimenting with the "Features Demo" but it's not behaving as I expect.  Perhaps there's documentation about what I should be expecting in the MEMS Studio somewhere that I'm missing? 

I am using Mems-Studio for my FSM project. I am testing the state machine, and everything is working fine; I can see interrupts. However, in the debug tab, when debug mode is enabled, the table does not compile, and I cannot observe the program's behavior. I used LSB data as shown in the examples for unico gui  

Dear ST/Forum,Preamble:We are using the LPS22HBTR pressure-temperature sensor in some PCB assemblies.The data sheet indicates a pressure reading range with defined accuracy from 260 to 1260hPA/millibar and an absolute maximum overpressure value of 2MPa (20000mbar).We are using the sensor in a vacuum application, where we expect them to not be exposed to vacuum unless there is a leak in part of the assembly. From the data sheet, we have noted there is no minimum safe pressure defined but we naturally expect the pressure readings to be at least inaccurate below 260mbar as it falls outside of the range quoted as "accurate". However we note that readings are given that seem at least sensible down to about 1mbar and then when the pressure goes lower, the sensors starts to read 4096.159874325 or similar, with the digits to the right still decreasing. Lower still and 4096 changes to 4095. We have not continued to note the readings at thes