MEMS (sensors)

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 two devices attached. You can cl

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, Jay

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_z_raw -19111 11246 -3500 root@FAFUSION:/sys/bus/iio/devices/iio:de

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 !

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; /* FIFO配置 */ //配置FIFO ODR 208Hz lsm6dsl_fifo_data_rate_set(&dev_ctx, LSM6DSL_FIFO_208Hz); //配置降采样率 为0 按照输出ODR直接存储到FIFO lsm6dsl_fifo_gy_batch_set(&dev_ctx, LSM6DSL_FIFO_GY_NO_DEC); lsm6dsl_fifo_xl_batch_set(&dev_ctx,

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 these low pressures.Temperature readings seem unaffected by

We are currently trying to run experiments with the ILPS22QS sensor. According to the datasheet, when setting the SWRESET bit in the CTRL2 register to 1, it should self-clear when the reset is finished - but this never happens. The bit stays 1, and this also effects the official driver located at https://github.com/STMicroelectronics/STMems_Standard_C_drivers/tree/master/ilps22qs_STdC - it just runs in an infinite loop, waiting for the bit to clear.I have written my own small application to verify this.We use a Raspberry Pi as the I2C host. Does this has anything to do with it, or is the datasheet not up-to-date?

Hi, I use the ISM330DLC to measure the tilting of an excavator arm (similar to an inclinometer). I have observed that some ISM330DLC accelerometer sensors exhibit misalignment in their Z-axis measurements. For example, while the X and Y axes produce values ranging from -1000 to 1000 mg, the Z-axis measurements range from -500 to 1500 mg.To compensate for this misalignment, I apply an offset variable. However, the issue is that some sensors initially show good alignment when tested in my office, but after being installed on excavators, they develop misalignment over time, similar to what I described above.My questions are:What could be causing this misalignment to appear over time?What steps can I take to prevent this from happening?Thanks

I'm trying to add an LIS2MDL (STEVAL-MKI181V1) magnetometer to my LSM6DSV32X's (STEVAL-MKI240KA) sensor hub. I can't get the LSM6DSV32X to properly identify the LIS2MDL, and I'm not sure if it's a hardware- or firmware-related problem. My current hardware configuration is:SCx on MKI240KA tied to SCL on MKI181V1SDx on MKI240KA tied to SDA on MKI181V1INT2 on MKI240KA tied to DRDY on MKI181V1Jumpers on MKI240KA shifted to SCx/SDx positionsCS on MKI181V1 tied to VddFor context I'm using Zephyr RTOS, but the initialization sequence for the LSM6DSV32X should be the same, especially since it fails right at the beginning when attempting to identify slaves. From the LA output, it looks like the LSM6DSV32X is trying to communicate with the external sensor but it can't sufficiently drive its SCx/SDx pins?

Hello,I am writing a firmware with nrf52832 microcontroller and I have interfaced ST's LSM6DSL module. I am facing some issues regarding power consumption of LSM6DSL module. I have used 10K resistors with sda, scl, sdO and cs pins is this correct.I am initializing my module below are the commands : using the wake up interrupt with inactivity function enabled to power down gyroscope.uint32_t app_mpu_int_enable(void){uint32_t err_code;err_code = nrf_drv_mpu_write_single_register(LSM6DSL_ACC_GYRO_TAP_CFG1, 0xF0);if(err_code != NRF_SUCCESS) return err_code;err_code = nrf_drv_mpu_write_single_register(LSM6DSL_ACC_GYRO_WAKE_UP_DUR, 0x00);if(err_code != NRF_SUCCESS) return err_code;err_code = nrf_drv_mpu_write_single_register(LSM6DSL_ACC_GYRO_WAKE_UP_THS, 0x30);if(err_code != NRF_SUCCESS) return err_code;err_code = nrf_drv_mpu_write_single_register(LSM6DSL_ACC_GYRO_MD1_CFG, 0x20);if(err_code != NRF_SUCCESS) return err_code;return NRF_SUCCESS;}uint32_t app_mpu_init(void){uint32_t err_code;uint

Hello,my team is planning to use the gyroscope of the part LSM6DSOX in a health tracking device,and one of the engineers noticed that the readings from the Gyroscope often have measurements that go beyond ±2000dps (specified in the datasheet as Full Scale).When converting raw data to dps, based on the Angular rate sensitivity, 2000dps would correspond to around 2000dps/70mdps ≈ 28,571 (raw data). But there are raw data readings higher than 28,571.The datasheet does not cover results beyond ±2000dps.Is there any validity for readings beyond ±2000dps, to the point offor example using the given Angular rate sensitivity to convert raw data output of 32767 to ≈ 2,293dps (15% beyond Full Scale)?Or could there be any distortion involved, making readings beyond 2000dps invalid? Best Regards,

HiI managed to read both accelerometer and gyroscope ISM330DLC in "polling" mode with INT1 pin with 3330 output data rate, but my goal is to reach peak data rate (6660 samples / s) so I need to use FIFO and this is where my problems start, I dont know how to set FIFO properly, results in FIFO are intertwined. Could you show me a problem in my configuration? I have some success with enabling FIFO but I have no clue how to configure it to reach my goal which is reading acc ang gyro via primary SPI with max data rate (6660 Hz) and with lowest latency (low set fifo watermark) My code   /* Header of application modules */ #include <sensors-board-app/logging.h> #include <sensors-board-app/ism.h> #include <sensors-board-app/ism330dlc.h> /* Header from CubeMX autogenerated code */ #include <main.h> #include <spi.h> #include <gpio.h> /* Constants */ /** @brief Timeout of ISM330 SPI interface */ #define ISM330_SPI_TIMEOUT_MS 100 /* Priv

HI, it seems to me that reading the LIS2MDL sensor only works correctly if I read first the X axis, then the Y axis, and finally the Z axis separately, each axis in a separate SPI transaction. My settings:- continuous measurement, output data rate set at maximum 100Hz- temperature compensation turned on- high resolution mode- low pass filter disabled, offset compensation disabled- i2c disabled, SPI 3-wire clocked 10MHz, BDU enabled- data ready interrupt on INT pin triggers enqueuing event into event queue, then main loop perform readout after some time (there are other higher priority tasks) My observations:1. Reading 8 bytes in one SPI transaction (from OUTX_L_REG 0x68 to TEMP_OUT_H_REG 0x6F) to read all data does not work at all, temperature data is broken, you need to split readout into 6 bytes of "axis data" and 2 bytes of temperature data2. In certain edge cases of my application when possible readout latency is high I have incorrect readouts of Z axis from time to time

MLC was working and suddenly stopped working , checked all the registers related to MLC and all the writes and read were happening properly.Even tested accelerometer data in the same state and it was also working fine.My device gets powered on using coin cell battery and after draining out the power , MLC started working (power dissipation in this scenario was much high than the normal scenario)

Hello everyone,I'm using the II2SDH accelerometer and want to collect the data whenever the Data Ready Interrupt is fired. I'm using the INT1 pin for that and this is my configuration: SPI_WriteByte(CTRL_REG1, 0x9f); // Low power mode, 5.376Hz data rate, XYZ Axis enable SPI_WriteByte(CTRL_REG2, 0x00); SPI_WriteByte(CTRL_REG3, 0x10); // INT1 on data ready SPI_WriteByte(CTRL_REG4, 0x00); SPI_WriteByte(CTRL_REG5, 0x00); SPI_WriteByte(CTRL_REG6, 0x00);The INT1 pin is configured as external interrupt mode on STM32, but the interrupt won't triggered. Is there any other ways to collect the data correctly? Otherwise my FFT calculation is incorrect.Any ideas how to fix the problem will be appreciated. Thanks.

I need to configure LIS3DH to generate FIFO full interrupt in INT1 pin. Once my MCU gets the hardware interrupt, it will read entire FIFO. And the loop should continue. Can anyone help me what are the correct steps to configure and read FIFO?Regards,