MEMS (sensors)

Posted on October 06, 2017 at 16:09Hi all,I am trying to implement the self-test function of the LIS3DSH, but the results I am getting do not agree with the numbers in the device datasheet. Here is my procedure:1) Set -/+2g range and 400 HZ ODR.2) Capture 20 samples in normal mode (ie ST2:1 = 00 in CTRL_REG5)3) Capture 20 samples with positive sign self test enabled (ie ST2:1=01)4) Compute the average difference between the 2 sets of samplesAccording to the datasheet the difference should be 140 mg for the X and Y axes and 590 mg for the Z-axes. However, I have run the self-test on 10 different boards with an LIS3DSH and for X and Y I get values between 175 and 220, while for the Z axis values between 500 and 620.The results look pretty consistent when the test is repeated on the same device, but there is quite a big variability from one device to the other. The datasheet does not specify any error ma

Posted on January 04, 2018 at 16:28Hi everyone,I'm using the lsm6dsl for acceleration measurement. But I'm getting big stationary offsets and I was wondering is that normal? Here are measurements from 5 different boards and all of them were carefully positioned to be exactly at the same place. xyz-159-411110-7-7810378670110010-981089171221162Is this normal operation? In datasheet Linear acceleration zero-g level offset accuracy is specified at ±40 mg (typ), but my measurements are as much as 6 times that.. Am I doing someting wrong? In the datasheet they say that sensors are all factory calibrated before they go out of factory, but I do not see any register or anything with calibration values. Only ones for user calibration.I hope my message was clear, sorry for my English.ThanksMartin

Posted on January 12, 2018 at 07:51I need the MTBF/FIT rate for part number STMPE811QTR. Thank you.

Posted on March 28, 2017 at 17:08Hi,is it possible to know the minimum delay required to wait between register writing during the self-test?I write down my code, to make myself more clearwhile(1) { BYTE xH = 0; BYTE yH = 0; BYTE zH = 0; //HPF disabling writeRegAccel(BYTE_REG2, WRT_CTRL_REG2_WO_MS); //Minimum delay to swotch from a mode to another delayMs(7); //I set the frequency at 5k376 Hz writeRegAccel(LOW_PWR_MODE_5K376HZ_W_XYZ, WRT_CTRL_REG1_WO_MS); delayMs(7); //I read the 3 H axis //First reading with garbage data xxx1: if(((readRegAccel(STATUS_REG)) & 0x08) == 0x08) { readRegAccel(OUT_X_H); readRegAccel(OUT_Y_H); readRegAccel(OUT_Z_H); }else{ goto xxx1; } //Second reading of the 'real' datas xxx2: if(((readRegAccel(STAT

Posted on December 15, 2017 at 20:25Hi, I'm working with a LSM6DSMTR device connected via I2C to a Nordic Semi nRF52382.  I would like to use the FIFO feature and have a question about the address rounding:If I start the multiple data read at the FIFO_STATUS1 register and read 154 bytes, would that read the 4 bytes of status registers and 150 bytes of FIFO data?  Or does the first address have to be the FIFO_DATA_OUT_L register in order for the rounding to take effect?#rounding #fifo

Posted on January 09, 2018 at 15:53I have a http://www.st.com/en/evaluation-tools/b-l475e-iot01a.html, which I am using now to learn about how ST MEMS sensors work and if I can use them in my future PCB designs.I have found recently that ST provides a library to mix 9-axis sensor data to calculate the orientation of any device. This libraries are in the http://www.st.com/en/embedded-software/x-cube-mems1.html.In my case, I want to use the 'MotionFX' library, mixing the data from Magnetometer+Gyroscope+Accelerometer which there are in this board.My problem is that the function 'MotionFX_initialize()' gets stuck and never leave. Due to the fact that ST doesn't give us t

Posted on January 10, 2018 at 13:04Dear Team,In H3LIS331DL Datasheet, Page number 18, Ton (Turn-on Time)  Test condition : ODR = 100Hz, Typ. 1/ODR+1msBy this I understood that if ODR is 100Hz then we need 11ms after Accel is turnon.Then what about other ODR Settings ? i.e., if we configure ODR as 50 Hz , 400 Hz & 1000 Hz then do we need any Turn On time or not required.Thanks for your response in advance.Siva.#odr #h3lis331dl #h3lis331dl-odr

Posted on January 09, 2018 at 01:22I am wanting to use Unico 5.0.0.0 with the STEVAL-MKI179V1 board but there does not appear to be a device name / device part for this board.What should I do?

Posted on January 08, 2018 at 16:39Hello,I am using IIS2DH to work for my application. But the problem rises when I measure the current it is consuming. At 25Hz with 40ms INT2 duration and Low Power Enabled with all axis, I am observing a current a current of 500uA which is not according to what mentioned in the data sheet of IIS2DH. The configuration is shown below:CTRL_REG1: 0x3FCTRL_REG4: 0x20CTRL_REG6: 0x20INT2_CFG: 0x04INT2_THS: 0x05INT2_DUR: 0x01The above configuration works perfectly for my application. However, it is consuming a lot of current. Am I missing something? Please help.Also, could anyone explain to me as to how BOOT_I2 bit on  CTRL_REG6 work ? what is its function? Where can i find information about it? #iis2dh

Posted on January 10, 2018 at 06:33Hi,can i use 7 lps22hb on I2C bus?thanks,francesco

Posted on January 10, 2018 at 00:28I'm trying to build an example project that comes with the 'STM32CubeExpansion_MEMS1_V4.2.0' using Keil. It shows the following error: startup_stm32l152xe.s: error: A1023E: File '..\..\..\..\..\..\..\Drivers\CMSIS\Device\ST\STM32L1xx\Source\Templates\arm\startup_stm32l152xe.s' could not be opened: No such file or directory I'm using X-NUCLEO-IKSO1A1 expansion board. Other examples that come with STM32Cube library build and flash fine. (Eg Blnky)Would love some help figuring this out. Thanks #x-cube-mems1 #iks01a1 #nucleo-l152re

Posted on January 09, 2018 at 17:15any help to find the spi_driver for ais328dq

Posted on January 08, 2018 at 15:19Dear Team,I am trying to configure CTRL_REG4 of H3LIS331DL chip register value multiple times with default configuration, which is creating a problem of not generating data ready interrupt. If I am not configuring it then working fine. Could any one please tell me what went wrong or did I made configuration as wrong or Accel chip itself internally having the mechanism of if we configure CTRL_REG4 with multiple time default value then Data Ready Interrupt will not generate? Please help us finding on this.Thanks,Siva.#h3lis331dl #h3lis331dl-data-ready-interrupt #h3lis331dl-configuration

Posted on January 08, 2018 at 08:08Hi,  I am working on a custom board wherein, I am using  LIS2DE12  accelerometer. The custom board draws around 0.1mA current. After the removal of the accelerometer from the board, the board drwas only 3uA current. So, I  would like to disable the accelerometer operation for minimising the current consumption, and for this, after initialization, I am writing the power down command 0x00 to the register CTRL_REG1 (20h). But the accelerometer still draws 0.1-0.2mA current. Please suggest the possible reasons for the same.   Thanks#lis2de12 #accelerometer

Posted on January 05, 2018 at 18:23I have just downloaded and using the 'STM32CubeFunctionPack_BLESTAR1_V1.4.0'.What I had noticed is, after calling aci_gap_start_general_discovery_proc() would take ~10 seconds forGAP_Start_General_Discovery_CB() being called with event 'DEVICE_DISCOVERY_COMPLETE'.Would like to know any way to improve this time ?

Posted on December 23, 2017 at 05:47Hello,I am using LIS2DE12 Accelerometer in my device interfaced with 32 bit STM32L4 sereis.Looking into the datasheet LIS2DE12 having two INT pins.My question is do i need to interface both pins with micro controller or single pin will work keeping other pin open.Application is Fleet Management System.#mems #accelerometer #lis2de12 #gyro

Posted on January 04, 2018 at 08:44I am interfacing sensor with Micro controller and controller is working at +3.3V.VDD_IO and VDD are two power supply pins in sensor.If i am giving common supply +3.3V of controller to VDD_IO and VDD , will it work?ORDo i need to give seperate voltages for both supply pins?Suggest me.Thanks.

Posted on December 29, 2017 at 04:40How I convert accelerometer X, Y and Z axis raw data into the unit of G. Can someone provide me the which equation I have to apply on the raw data so I can get the results in G unit. Moreover, how we calculate roll, pitch, and yaw from the accelerometer's raw data.

Posted on August 15, 2014 at 04:00Hi everyone , I am new to using ST Sensor.I have saw the document , But I can not find the I2C Address.What is the I2C Address fot HTS221 humidity and temperature Sensor ?Thanks in advance. #i2c-address #rtfm #hts221

Posted on February 01, 2017 at 09:47Hi, allI'm using some VL6180X devices on my custom board.Then, their range offset seem to change every start up about �5mm, although I adjust the offset as directed in application note.What affects the range offset?Under normal circumstances, is it enough with only once adjustment?Is this problem specific to my board?Does anyone has the same issue?Best regards,Ishikawa#proximity-sensor #multiple-vl6180x #offset #vl6180

Posted on January 06, 2017 at 08:53Hi, I want to use VL53L0X for an application that will detect objects in close range, as close as possible in the order of a few cm.How to configure the sensor to get maximum performance at close range using the API?Can we use smaller VCSEL pulses?#vl53l0x

Posted on March 01, 2016 at 17:10I undesratnd that ''ST Time of Flight technology uses photon detectors to measure the time it takes a generated light pulse to leave our product, then reflect from a target and come back to our device.  Knowing the time it takes, an accurate distance measurement can be calculated knowing the speed of light.''My question is: since VL6180X calculate the distance as the time between transmitting and receiveing the infrared, how can it measure distances (e.g. about 1cm) which correspond to a time of flight in the order of picoseconds ?Thanks #vl6180x

Posted on August 03, 2017 at 10:30HiI am testing the VL53L0X time-of-flight sensor, in order to find out how resistant it is to ambient light and it turns out that if you point a light source with a high IR content (like a halogen light bulb) towards the sensor it cannot measure the distance. Even if the illuminance is very low. It simply says 'No Target'.The problem gets worse the steeper the angle is with respect to the optical axis. Has anyone had this problem and found a solution?Best regardsSoren#light-intensity #light #vl53l0x #vl53l0 #tof #ir #time-of-flight #ambient-light #halogen

Posted on December 01, 2017 at 09:38I would like to use the VL53L0X to determine the position of a linear position actuator (i.e., a device long and thin relative to its width).  Therefore, I would like to restrict the effective field of view of the VL53L0X from the 25� exclusion zone specified in the user guide to a narrower beam.Would it work to put an opaque tube along the optical axis, with an absorbing coating on the inside?  Together with a small, but highly reflective target (e.g., reflective tape used for reflective signs)?  Other suggestions?Can you provide any additional guidelines for optical configurations for the device, e.g., collimating optics?Also, for the stated accuracy (e.g., 3% for high accuracy measurements), does that represent jitter in measurements at a fixed position (i.e., irreducible error).  Or is it an absolute error measurement, with somewhat better reproducibi

Posted on October 23, 2017 at 16:13Hello.Does anybody knows if is possible to decrease the VL53L0X FOV putting in front of It a short piece of plastic (dark?) pipe?Could it works enough fine or the cross-talk will become unacceptable?Any other options to decrease the detecting FOV?Thanks in advance.#vl53l0x-fov-decrease-narrow-angle