MEMS (sensors)

Hi All,My name is Stefano, and I developed firmware for an embedded sensor that integrates the LIS2DW12 MEMS accelerometer. We encountered the following issue:At the end of the firmware development, we tested the current consumption across many of our new sensors, and the results were as expected;The new firmware was then put into production;After a few months, we noticed that some sensors had a lower-than-expected battery level, despite their typical lifespan;We retrieved those sensors from the field for analysis;Upon analysis, we discovered that the issue was due to abnormal current consumption by the sensor, with an average current (Iavg) of approximately 300 mA instead of the expected 7 mA;The sensor's current consumption returned to the normal range when the firmware powered off the accelerometer;After extensive investigation, we determined that his abnormal consumption is due to the resin potting phase, Main resin infos are follows: shore A hardenss of 74-80,Dielectric

I am reaching out regarding an issue I am experiencing while reading register values from the ISM330DLC sensor using a Python script over SPI. Specifically, I am encountering incorrect data when accessing certain registers.For example, when reading the WHO_AM_I register (0x0F), I receive a value of 0x7F instead of the expected 0x6A. This discrepancy suggests there may be an issue with the communication setup or the sensor response.Here is a brief outline of my setup and process:Hardware:Raspberry Pi 5 connected to the ISM330DLC via SPI.Correct wiring verified (VDD, GND, SCL, SDA, CS).Software:Python with spidev library for SPI communication.SPI mode set to Mode 0 (CPOL=0, CPHA=0).SPI clock speed: 1 MHz.Code Snippet:import spidev spi = spidev.SpiDev() spi.open(0, 0) spi.max_speed_hz = 1000000 spi.mode = 0 # Reading WHO_AM_I register reg = 0x80 | 0x0F # Set MSB for read operation response = spi.xfer2([reg, 0x00]) print(f"Response: {response}") Despite these checks, the returned v

Hello ST Forum,I am currently working on a project that aims to help surfers analyse their surfing sessions. The goal is to use a LSM6DSV16BX attached to a surfboard, using the IMU to analyse the board's movement, and one of the QVar channel to detect whether the board is put in water.I was wondering about how to use the second QVar channel. In particular I was wondering if it could be used to detect the presence of the surfer on the board without contact.In the August 2022 revision of AN5755, the document states that using a single electrode is recommended for presence detection, especially in cases where powerline noise is weak, which seems to be my use case. However, the surfer and his/her surfboard will be immerged in seawater. Do you know if it is possible to detect human presence in these conditions ?Additionnaly, since QVar channels seem designed to be used differentially, do you know if I can use one channel to detect if the device is in water, and the other channel to detect a

I need the thermal resistance Junction to Ambient for LIS2DH12, LGA-12 package. 

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Hi. I have both the ST1VAFE3BX and the X-NUCLEO-IKS4A1 and I'm trying to read data from the biosensors using MEMS-studio, but I don't see how to get MEMS-studio to recognize the biosensors.  The documentation for the biosensors has instructions for working with the ProfiMEMS tool (a different motherboard).  In that documentation, it shows that there are biosensors. The docs for the ST1VAFE3BX also indicate that it will work with the IKS4A1 but it's not obvious to me how to make MEMS-studio "see" the biosensors as a data source.any help would be appreicated.TIA.-Rich 

We are designing an STHS34PF80 into an occupancy sensor and the plan is to have an HDPE window to protect it.  To test the response in the actual product we purchased 1/16" (1.5mm) HDPE sheet and put it over the sensor.  The fresnel lens with the dev kit was removed.  Surprisingly the Tpresence triggers when the sheet is over the sensor, and so the device doesn't seem to be seeing through the HDPE sheet.My first thought is that the HDPE is doped or just wrong somehow but I thought I'd ask if anybody else has seen something like this.Thank you.

Hi all, I am currently working with the STEVAL-PROTEUS1 Board, which incorporates the STM32WB5MMG module and the IIS3DWB high-bandwidth accelerometer sensor, interfaced via SPI_1. According to the IIS3DWB sensor datasheet, it supports a clock frequency of up to 10MHz and an Output Data Rate (ODR) of 26667Hz (37 microseconds). My objective is to collect sensor data at an ODR of 26667Hz. Here are the steps I have taken so far: Configured the core to 20MHz. Configured SPI_1 to 10MHz. Configured the sensor to generate an ODR interrupt, which is successfully triggering every 37 microseconds. The issue arises when collecting data (6 bytes) from the sensor, which is taking 125 microseconds using HAL functions in blocking mode. Ideally, this should not be the case. I have also tried using non-blocking mode (DMA), but it is taking more time (175 microseconds). Could anyone help me understand if the HAL function is supposed to take 125 microseconds, and why DMA is taking more time than the blo

Hi,I recently bought a SensorTile(STEVAL-STLKT01) and I want to modify the default project for my own usage case.Based on the information I found, I downloaded the source code from https://www.st.com/en/embedded-software/fp-sns-allmems1.html (Github source) and then I opened the project "STM32L476JG-SensorTile" with CubeIDE Version: 1.17.0 and then I tried to build this project without any modifications.The first problem I encountered is that the defined variable "STM32L4xx" seems not exist so I have to add it manually into the path and symbol property:However, I encountered another problem that the header file "STC3115_Battery_Conf.h" is not exist:I am completely stuck at this point since I cannot find it anywhere even in the Github....Can someone guide me how to build this project and download it to the SensorTile platform?Thank you!BR,Mike 

Hello,for a new project we are avalutaing the use of an iNEMO inertial module in conjunction with the motion fx library with the goal of doing position estimation with dead reckoning.My doubt is about the library, since we are forced to use a thrid party MCU (an ARM M4), can I import the library on any ARM M0/M4/M7 mcu? Or does it target ONLY st devices?Thank you,Davide

Hello,I searched the forum and found out a topic regarding the sensing technology of LIS3MDL sensor. The topic mentioned that LIS3MDL is a TMR sensor, however no support documents are included to further investigate the integrated circuit of the sensor.Moreover, I found several studies/papers claiming the LIS3MDL is an AMR sensor.My question is: Is there any official document available regarding the underlying sensing circuit and phenomenon the LIS3MDL sensor is using?Thank you for your time and support.

Hello,can anyone tell me what I am doing wrong?For example, I can't get app_mems.c (eCompass) to debug.The debugger does not stop when I set a breakpoint on subsequent function calls because, for whatever reason, the “SensorReadRequest” always has the value 0.:RTC_Handler(&msg_dat);Accelero_Sensor_Handler(&msg_dat);Gyro_Sensor_Handler(&msg_dat);Magneto_Sensor_Handler(&msg_dat);Humidity_Sensor_Handler(&msg_dat);Temperature_Sensor_Handler(&msg_dat);Pressure_Sensor_Handler(&msg_dat); I also need direct access to the variable “heading”. 

We have an issue with LSM6DSM and LSM6DSV. Sometimes they start consuming abnormally high current of 2.5 mA, which is about 200 times more than normal. Most reliably this can be reproduced when their SPI clock input pin 13 is driven by a week 47k pull-up / pull-down resistor.It seems that LSM6D becomes unstable and begins to oscillate. This happens when LSM6D is in any operation mode: in a full shutdown mode just after cold start, in a low power mode, any SPI speed, I2C disabled, etc.The reason why we drive SPI clock input by a week 47k pull down resistor is that LSM6D suppose to wake up the STM32L496RGT6 MCU from the shutdown mode. In the shutdown mode, the STM32L496RGT6 has only a week pull up/down option to drive its pins. But the voltage on the LSM6D SPI clock input pin 13 is about 7 mV and hence is well below the required logical 0 level. Documentation does not mention clock driver impednce and neither SPI nor I2C standards require low impedance input drivers.We found a tempo

I am trying to use the DATALOG1_V1.1.0\Utilities\Python_SDKWhen I call the script hsdatalog_data_export I get an error: "No module named 'click'What to do to make these scrpits work? Pyhton is V3.7.8

Posted on October 16, 2016 at 11:59The LIS3DSH has a three channel 10 bit A/D converter but I can't find any information on it. What is the accuracy? (I could tie one channel to a voltage reference for calibration if necessary) What is the input voltage range? What is the maximum input current? (will I need to buffer the channels) #lis3dsh

Hi, community,   I have a bespoke board running an rp2040 and have been coding the LSM6DSO from the spec, along with using web-found python and cpp examples as starter code. There are several things I haven't found enough detail on and would like help.  1. if I read 2 byte temperature from the fifo data address, do I have to still read the full 6 bytes from the fifo data register and toss the 4 unused bytes, to keep the fifo syncronized with 6 byte data reads? Or can I read 2 for the temperature tag, then read 6 on the next gyro or acc tag? 2. how do I uncompress compressed data from the fifo? The only reference I could find leads to a dead URL. And same thing, if compressed, do I still need to read 6 bytes? Related to that, the driver cpp code on github seems to be empty, as if it was once there but was removed. 3. How do I decode the fifo timestamp info? thank you,   bob s

Hello,I am trying to get the temperature from LSM6DSVX sensor. Accel and gyro are working well but I can't get the temperature. The buffer cannot be enable for temperature. It works for Accel  and gyro buffer can be enable.their is something specific to do for the temperature ?  cmd line :echo 1 > /sys/bus/iio/devices/iio:device3/buffer/enablereturn : write error : invalid argument.

Hello Team ST and Community,I have following code for step count for our wrist-based device. We use LSM6DSO IMU.The step debounce threshold has improved the step count accuracy. It is currently set to 20. But, I could not get rid of the false positives. It also counts steps when I am typing on a keyboard and other minor movement when it exceeds step debounce threshold (e.g. typing more than 20 characters will start step count).I tried setting delta time period to mitigate this issue but it does not help a lot. Therefore, I have two question.1. Am I programming delta time period correctly? My understanding is that a step interrupt would be generated if a step movement happens between 256ms and 512ms as shown in the code. Please correct me if I wrong.2. How can I reduce false positives from minor movements? The false rejection advanced mode option is not that accurate to reject minor movement. Thank you,Aakash.  //Step counter interrupt lsm6dso_pin_int1_route_get(&amp

Hello, In general, I would like to better understand the relationship between the sampling frequencies of the FIFO and the Accelerometer (ISM330) and how to adjust them correctly for my application, could anyone give an example? In my case I have the following configuration:ISM330DLC_ACC_SetOutputDataRate(&MotionSensor, 26.0f)ISM330DLC_FIFO_Set_ODR_Value(&MotionSensor, 6660.0f)ISM330DLC_FIFO_ACC_Set_Decimation(&MotionSensor, ISM330DLC_FIFO_XL_DEC_32)That is, the ISM is sampling the accelerometer at 26Hz, the FIFO with decimation is configured to store at a sampling of approx. 208Hz (6660/32), which indicates that in 1 second the accelerometer saves 8 samples (208Hz/26Hz) from the accelerometer in the FIFO. Is this correct? For a practical application, for example, a motor with 1000RPM (1000/60=16Hz), would the frequency I need to adjust in the ISM330DLC_ACC_SetOutputDataRate function be at least ISM330DLC_XL_ODR_52Hz? Your feedback is much appreciated.Re

Can someone help me how to use one interrupt pin for Activity/Inactivity and another for Free Fall detection? I need to use it in the lowest possible possible mode as my device is coin cell battery powered.Regards,Asish Banerjee

Hello,  I am trying to detect Single & Double tapping on LSM6DSL accelerometer. I am configuring the relevant registers as follows: CTRL1_XL=0x60TAP_CFG=0x8ETAP_THS_6D= 0x8INT_DUR2=0x45WUP_THS=0x80MD1_CFG=0x48 Every time I tap the accelerometer, and interrupt is generated and the I read the TAP_SRC register to identify the type of the type. The  X_TAP, Y_TAP and Z_TAP  bits are updated properly. But I NEVER get the SINGLE_TAP and DOUBLE_TAP bits set - They are always ZERO. Can someone please help me what am doing wrong? Thanks

I am trying to get the an values ready interrupt working, but I cannot seem to find the right configuration of registers. Normal threshold interrupts are working as expected.After the normal setup and using all different speeds ODR, when setting INT1_CTRL to INT_DRDY_XL active, I do not get any interrupts. The oscilloscope shows no change as well on either H_LACTIVE as well. Is there a sample that can be provided which has a working implementation of the interrupt working? So far all public sources have non working code. As an MCU I am using an ESP32 and Arduino.Here is my current initialisation:// Enable accelerometerwriteRegister(0x1F, 0x38); // CTRL_REG5_XL - Enable XYZ axeswriteRegister(0x20, 0x60); // CTRL_REG6_XL - ODR 952 Hz// Set up interrupt generator and DRDYwriteRegister(INT1_CTRL, 0x01); // Enable IG_XL (bit 6) and DRDY_XL (bit 0)writeRegister(CTRL_REG8, 0x00); // Active HIGH, push-pull 

Hi,We are intending to use AIS2IH for one of our projects.We would like to change some settings while the device is running and see their effects on the performance/power consumption, in order to decide the best settings for our purpose.I would like to ask if we can change the below bitfields on the fly. If we can not, could you please provide the steps to change them correctly?CTRL1 register:ODRMODELP_MODECTRL6 register:FS (full scale selection)LOW_NOISEKind regards,Kerem

HiI'm trying to use two ISM330IS sensors both connected to the same external microcontroller.I want to synchronize accelerometer and gyroscope sampling (and the ISPU) to the processing cycle (1ms) of my controller.They should optimally both start the sample at the same time, triggered by a pulse from the microcontroller connected to both the sensors.I'm not 100% certain if this is actually possible. In AN5850 the INT2 pin is described like it may be used for this purpose (I²C master external synchronization signal (MDRDY)). It is described that this pin can be used to externally trigger sampling of the "sensor hub", which is a number of optionally connected I2C sensors. The description in section 6.2.1 of AN5850 is:"When this bit is set to 1, at least one sensor between the accelerometer and the gyroscope has tobe active and the sensor hub trigger signal is the INT2 pin"Does this mean that I can use a pulse on the INT2 pin to trigger sampling of the gyro and accelerometer, or

Hi,I'm working on a prototype of a device. One of this device features is to collect data from gyroscope, accelerometer and e-compass. It is very important that the device will be ultra-low-power. One goal for the prototype is to verify how much energy will that device consume.I have a question about components which I could use to build this prototype. I'm going to use STM32 NUCLEO-L432KC which will provide me ultra-low-power MCU. Is there any evaluation board with sensors (accel, gyro, e-compass) which I could connect to the Nucleo board?