MEMS and sensors

Posted on February 17, 2017 at 11:04ST politics about VL53l0X Hy ST,in a customers project I deal with the VL53l0X quite a bit, we have a nice prototype up and running and are about to decide if we want to start designing a series device.Ever once in a while I look into this forum and follow the discussion about the device and come to the conclusion, that ST is not very willing to provide further informations about the insides and usage of the device.The thread https://community.st.com/0D50X00009XkeHcSAJ nails it down very nice.Can anyone of ST maybe give some information about the politics around VL53l0X? Will there be a better support of the device in the future? Is it running in high volume already? Was it designed for one target application and no other user or project is supported? We probably must take the response to these

Posted on March 01, 2017 at 08:30Hi,In the 'Examples of output data' section of the LSM6DS33 application note AN4682, there are tables showing examples of the output register values and the corresponding acceleration and angular rate values for a given scale. Can you please elaborate how the values are calculated?Regards,Prachi #lsm6ds33 #accelerometer #gyroscope

Posted on February 26, 2017 at 23:32Hello.I´m having problems on SPI reading WHO_AM_I register of a LSM9DS1 mounted on STEVAL-MKI159V1 : the correct answer is 0x68 but very often I got 0x28. The suspect that the level of bit 6 was not correctly set is confirmed by some traces of the oscilloscope but I need to say that:1) Attaching probes fixes the problem : for some reasons the loads of probes solve the problem.2) I got the two attached pictures during the initialization of the board or shaking a little bit cables of a second circuit on a breadboard.  Summarizing the situation : in normal condition I got very often the incorrect value 0x28 but when I connect probes the problem disappears and I have always the correct value 0x68. Only in some conditions - initialization phase in the first 10 seconds or shaking a little bit some connection cables of a breadboard - I got the two attached pictures. I read a post of an user w

Posted on February 28, 2017 at 12:56How to read a characteristic value which was written by android on Blue NRG.Please help

Posted on February 28, 2017 at 00:33Hey,   In my application there is a lot of high frequency vibration that I am not interested in. The goal is to detect acceleration along a single axis that lasts 200ms or longer, but is generally between 1/2 and 1/10 the magnitude of the noise (vibration readings). Finally, for performance reasons it is not feasible to read all the data from the accelerometer, an interrupt should only trigger when it is likely an event has occurred.    What I am trying currently: Stream to FIFO mode, adjusting threshold and duration in both 6D and AOI modes. 6D fails to trigger because vibrations send the reported acceleration bouncing back and forth between positive and negative values. AOI will trigger constantly because of the large magnitude of the vibrations. Is there anything else worth trying before looking for a different product? It seems like a product with a built in low

Posted on February 27, 2017 at 08:17Hello everyone,In the data sheet of LSM9DS1, it is stated in the first page that the device supports: Position and motion detection functionsClick/double-click recognitionHowever I cannot find anywhere in the data sheet describing how to use the features?  Could someone help me on this? Thanks a lot!#lsm9ds1-click-detection

Posted on February 24, 2017 at 20:11Hello everyone,To make this quick, I'm hoping to find any guidance on a particular issue we're having.We've developed a prototype wearable using ST's accel/gyro/magneto module. However we're trying to reduce the errors/drifts inherent to the Accel/Gyro (not concerned about the Magneto) and rather than using the common but complex Kalman filter, we're hoping to use the easier by rarer Explicit Complementary Filter algorithm to enhance the attitude of the system, preferably in C++ to use in our C# Application.Just not sure where to go or where to find answers.

Posted on February 23, 2017 at 08:04Hi all,I'm playing with the LSM6DSL sensor on the IKS01A2 board.I'm trying to use the FIFO to record and buffer accelerometer and gyro data.The accelerometer works fine and reading the gyro registers directly gives sensible data, however the gyro data in the FIFO for all 3 axes is *always* 0x7FFF (ie MAX_INT for int16_t).I have scoured the datasheet and the LSM6DSM application note and can't find any indication of why this might be happening.I've tried a huge amount of various settings, with no difference in outcome, currently using:X_ODR = G_ODR = FIFO_ODR = 416HzDecimation = 1 (no decimation) for both accelerometer and gyro.Typical FIFO readout looks something like this:...Got pattern    0 value 32767 (0x7fff) from FIFO with    6 words (empty=0 smartfull=0 overrun=0 watermark=0)Got pattern    1 va

Posted on November 07, 2016 at 11:56Hy,for a proof of concept I created five identical devices, each having 3 VL53L0X, so I have an overall of 15 VL53L0X that are mounted (behind an acrylic glass shade) and connected (via 2.8V, I2C) identically. During test of my devices I observe, that one of the sensors has quite exact the half sensitivity of all other devices: amplitude is about half, standard deviation is about four times of the other sensors.I can't see any optical explanation for this: no scratches nor soiling of the front glass. Might there be any other explanation? Do I need to characterize devives before I use them?RegardsHarald #vl53l0x #sensitivity

Posted on February 23, 2017 at 07:54The error says 'Symbol rotAcc multiply defined in osx_motion_pe.o and osx_motion_id.o'. But there is no such symbol in both their header files. I am trying to execute the MotionPE and MotionID libraries provided by STPlease HelpRegardsNitish#library #stm32l #motion #libraries

Posted on February 22, 2017 at 02:00I have went to just order the H version and found there is none left. Anywhere. So then I started looking and the US version is on stock. All the specs look identical but I just want to know for sure. Any help or insight would be great. Thanx

Posted on February 22, 2017 at 07:25Sensor tile (stm32l476jgy) hangs when trying to access osxmotionPM library without delay.Please Help...#stm32l4 #mems #pedometer

Posted on February 22, 2017 at 07:13On same set of code on sensor tile, the accelerometer some times outputs the data and sometimes it didn't on same set of code.main{BSP_ACCELERO_Init(ACCELERO_SENSORS_AUTO,&acc_handle1)   BSP_ACCELERO_Sensor_Enable(acc_handle1)while(1){      BSP_ACCELERO_Get_AxesRaw(acc_handle1,&acc);}please help with this...

Posted on February 21, 2017 at 18:22Hello,in wesu downloads I can find ResetManager, UsbDfu and OtaDfu applications in bin format.Are they available also in source format?Thanks in advanceFabiano

Posted on February 13, 2017 at 16:04HiIm having the device VL53L0X which I want to communicate with trough the I2C protocol to my STM32F401RE micro controller.Im using CubeMX from STM to setting up the pins which works fine, but I don't know how I 'connect' the I2C functions from the API with the I2C at the MCU.As far as I can read in the VL53L0X API Specification, something in the 'VL53L0X_platform.h' has to be adapted to the platform but Im not sure how to do it. Can somebody give me an example, and also point out what I has to change?Best regardsS�ren

Posted on November 11, 2016 at 10:45I always get the error 0b0111 (max convergence) if I make a range single shot measurement (I also don't know if other modes are working). I tried to disable the ECE but still the same. I tried it with the code from the ''VL6180X range and ambient light sensor quick setup guide''. Can anyone help me to get this working?Regards Simon #vl6180

Posted on November 21, 2016 at 11:22Because of the limitation, my project just can use 16bit MCU to drive VL53L0X. The API of VL53L0X is too complex and not suitable for 16 bit MCU, so I can't just  use the API directly...It is very time-consuming for simplifying.... #vl53l0x

Posted on February 20, 2017 at 08:57Hi,I am using LIS2DH in our custom board and I am trying to detect some scenarios using this accelerometer. I read the datasheet and application note and tested almost all features. But I'm not sure how to apply them to my scenarios. The sensor is connected to my device which is attached to an underground waste container. The accelerometer can not detect constant speed. So I can not know if the waste collection vehicle is lifting it up(assuming it is lifting it on a constant speed).  All I can do is detecting the transition between the device's stable position and the first movement using the free-fall interrupt on the Z axis.Is there any chance to differentiate the situation of my device between the stable and getting lifted on constant speed? Is there any article about collecting the accelerometer data for such scenarios?#teft #detect #lis2dh #accelerometer #lifting

Posted on February 13, 2017 at 17:37Hello I don't understand why I get value  aroung 1.3 Gauss ?Configuration :   LIS3_CTRL_REG2 = 0x00;   // Full scale +/- 4 G   LIS3_CTRL_REG1 = 0x1C;   // ODR=80Hz, XY LowPower   LIS3_CTRL_REG4 = 0x00;   // Z LowPower   LIS3_CTRL_REG3 = 0x00;   // Continuous-conversion mode   LIS3_CTRL_REG5 = 0x40;   // BDU = 1and I receive :   LIS3_OUT_X_L = 0xEB   LIS3_OUT_X_H = 0xEE      => MagX = 0xEEEB = -4373   LIS3_OUT_Y_L = 0x94    LIS3_OUT_Y_H = 0x07 => MagY = 0x0794 = 1940  &

Posted on August 25, 2015 at 13:12​Hi,I working with Barometric Pressure sensor LPS331AP.Its working good. but as this chip absoluted,then we changed design to LPS25HB.But this chip is reading 6.4mBar error apart from the actual measured value .We are not added any offset value and not done any our factory calibration.Just I reading the 24-bit data and displaing converted pressure.I did 't change any code,just I replaced LPS331AP by  LPS25HB chip.Advice me is it nesassary to change any code ? or any calibration or offset vaules need to set?/Please advice us...

Posted on February 08, 2017 at 21:16Good afternoon,I am trying to determine the theoretical accuracy of an angle calculated with the lsm6ds3 accelerometer.  From the spec I see there are a number of sources of inaccuracy/noise.  There is noise density that is dictated by range and sampling frequency, zero point change due to temperature and zero point accuracy.  Of these, zero point accuracy is listed as a constant value of +/- 40mg.  There is no mention of any factors that can be used to change this value for the better (e.g. lowering the range reduces the noise density).When we determine the angle we use the arctan of two of the readings.  For the 45-degree worst case that means we would get a theoretical measurement of x = 0.707g and y = 0.707g.  If I assume worst case zero point accuracy only on both of these values (+/- 40mg), one positive and one negative, I get x = 0.747 and y = 0.667.  That gi

Posted on February 16, 2017 at 23:37hello,we are using H3LIS331DL to record shock on our instrument.we have setup INT1 to interrupt when acceleration>threshold.when the interrupt occurs we read out values and store it.we have observed that sometimes we read out acceleration that is less than threshold.why is this happeningPradeep#authentix #h3lis331dl

Posted on February 16, 2017 at 15:48I am looking at the data sheet for the M24M02 and I want to read the Lock Status.  The data sheet says thisThe locked/unlocked status of the Identification page can be checked by transmitting a specific truncated command [Identification Page Write instruction + one data byte] to the device. The device returns an acknowledge bit if the Identification page is unlocked, otherwise a NoAck bit if the Identification page is locked.If I send the ID Page Write instruction plus one data byte, won't that actually write the data byte if the ID page is not locked?Or does this mean to send the Device ID byte plus one byte (which would be the first address byte in a real write command)?Thanks for your help.Tom

Posted on February 14, 2017 at 23:24We are evaluating the LPS25HB BP sensor, and have a couple of questions. I notice that several forum members have asked similar questions, but without receiving a reply. I would really appreciate an answer, as this would indicate that the LPS25HB is not an 'orphan', unsupported product.1) The datasheet mentions a soldering effect on BP, and says that a register is available to store a one-point calibration. There are no other details at all about this in the datasheet. We have found substantial (~0.5 kPa+) pressure inaccuracy in samples we have tested. Is this to be expected? Exactly how are we to use the calibration register? How is it calculated? Again, these are important points for any user, and the datasheet gives no meaningful information.2) We notice a very substantial temperature effect on BP. It appears that no temperature compensation is being done internally to the chip, although the datasheet

Posted on February 14, 2017 at 13:03Hi all,I have got a technical question, if is possible to get some helpful feedback, I would really appreciate it, please.I have recently purchased a LIS2DH12 accelerometer and I am plugin it within a Teensy module in order to check the right behaviour. I have only enabled �Z�axis by 0x20 and 0x30 registers.  However, my Arduino console also shows me that �X�and `Y` axis are enabled throughout the 0x31 register. So, my question is: Which registers should I configurate and keep in mind for just activate �Z�axis?Well, my Register configuration is the following one;while(i2cWrite(0x20, 0x34, true)); while(i2cRead(0xA0,i2cData,1));Serial.println(i2cData[0],HEX);while(i2cWrite(0x22, 0x40, true));while(i2cRead(0xA2,i2cData,1));Serial.println(i2cData[0],HEX);while(i2cWrite(0x23, 0x08, true)); while(i2cRead(0xA3,i2cData,1));Seri