MEMS (sensors)

Posted on November 15, 2014 at 08:55hi i m using lis3dsh sensor to detect the accidents. for this i need to detect the impact using the variation of the G value.. from sudden shift of 2g to around 16 g and also fall detection .. so far i am getting the raw values ax, ay and az .. how to calculate the G value out of this ?? should i dynamically recalibrate the sensor. ?? what are the offset and sensitity values i should adjust. please help me regarding this. thanks in advance #accelerameter-offset #accelerometer

Posted on November 14, 2014 at 20:55Hi i was trying to enable the data ready on accelerometer .however i'm not sure how to check whether it's enabled or not .i mean whenever i read the value in IG_SRC2 it shows that 0x00 also i have not enabled the latch option.Is there something else i need to set up before i enable INT_DRDY_A on CTRL4 Register ?

Posted on November 03, 2014 at 15:44Hello EveryoneI am working with the STEVAL-MKI121V1 board and Discovery-M1-Fw package, trying to get rid of the USB interface and replace it with SPI configured as Slave. My intention  for the the final system is to have the iNEMO-M1 connected via SPI to an embedded Linux box.I can see that the iNEMO_Gatekeeper is the interface between the outside world and the iNEMO through a Virtual COM using the USB as the transport medium.As far as I can see, there are two solutions to this. One is to change the Virtual COM to use SPI instead of USB, but in some way this doesn't make sense when thinking of standard USB-UART converters also configured as a Virtual COM's.The other solution could be to remove the Virtual COM and setup the SPI directly in the Gatekeeper, but this way I feel that I am missing something to complete the integration.I am mostly leaning

Posted on November 03, 2014 at 23:45Hello, I'm developing a compass module based on the LSM303D with a STM32F030x as host controller. I'm a little bit confused about the inconsistent PCB guidelines and application hints. In the application hints section of the datasheet for LSM303D it is stated, that ''Power supply decoupling capacitors .. should be placed as near as possible to the supply pin of the device (common design practice).'' Whereas all reference designs have their capacitors placed far away from the device to have a symmetric PCB layout. Does somebody have any experience with hardware designs of e-compass devices? Another question.. is it recommended to spare out the ground plane on the bottom side of the PCB as well? Thanks in advance. Marten #pcb-guidelines

Posted on October 21, 2014 at 16:28According to it's datasheet the LSM330D has a self test mode enabled by setting the self-test bit to 1 however there is no register entry I can find dor the self-test bit.Where is it ?

Posted on November 20, 2013 at 10:38Hi community, i am working on an application with the accelerometer and gyroscope in LSM330DL. At the moment I try to use the DataReady-Interrupt for the gyroscope. My understanding of DRDY-Interrupt is that whenever new data is stored in the register, the sensor pull down the DRDY-Pipe. I have tryed several configurations, hardware adjustments and so on but nothing works properly. The DRDY-Pipe is always in high-state. At the moment i have a very basic test program, where i initialize the sensor and wait for an interrupt. In the following my configuration of the gyroscope: REG1: 400Hz - 50Hz cutoff, normal mode, xyz - enable REG2: everything 0 REG3: I2_DRDY enable REG4: continuous update, LSB, 2000dps, 4-wire REG5: FIFO disabled, HPF disabled I asked the same question more than one week ago to the st-sup

Posted on March 30, 2014 at 09:25hi guys. for gathering data from adxl345 accelerometer i need to write some data in specified register in this sensor. but in stm32f4xx_i2c.c there isn't any function like :I2C_SendData(I2Cx, data);to write in a register which i know it's address.is there anybody to explain me the procedure of this matter, means connect adxl345(or any sensor which is connected through i2c  ) through i2c to stm32f4 #stm32f4 #i2c #i2c #discovery #accelerometer #discovery #stm32f4

Posted on October 31, 2014 at 21:54I'm a bit lost about the use of the acceleration filter bandwidth. How to choose the relevant value between 50 and 773Hz ? -- Fabien #filter #lsm303d #accelerometer

Posted on October 27, 2014 at 09:43Hi,we can get mm accuracy in diesel level measurement?   #vl6180x #proximity-sensor

Posted on October 22, 2014 at 11:41how get INEMO software demonstration, the server seem out of order, I try 6 times I receive, illegal character and after the server is out of order, try later

Posted on October 22, 2014 at 08:18Hello, i am using the iNEMO Lite soft version, namely INEMOEngineM1LI3,  the only thing i modified to work with the stm32f407 was some i2c functions, and the data/trafic on the i2c buss is ok. I tryied to display the roll, pitch, and yaw on a 20x4 LCD display, and the Roll axis is ok, in the meaning that it moves from 0 - 180 -180 -0 , However the Pitch axis only moves from 0 to 88 degree, if i try to move above 88 degree its starts decending to 0 again And the Yaw axis displays -121 degree, if i move the yaw axis the minimum value i can get is -60 degree The header and source code is the same as in the \INEMOEngineM1LI3\iNemo_M1_Applications\Source\examples\AHRS_Continuous.c Is this a demo software limitation? Tryed even my own sensor libs and using inemo ahrs kalman filters and algorithms

Posted on October 21, 2014 at 10:33Hi, I have one question about the SPI of the LIS3DSH sensor. Does it have a multiple byte read bit? On page 26/53 (datasheet) in figure7 there is a MS bit, but in the text it is not mentioned. Where is the mistake, in the figure or in the text? How is the resolution of the sensor? In the flyer ''3-axis digital accelerometers for smarter, easier-to-use and energy-efficient portable devices'' I get the information 14bit, in the brochure ''MEMS motion sensors'' the resolution is 16bit. Which information is right? Kind Regards #lis3dsh-spi-resolution

Posted on October 20, 2014 at 21:02My computer is unable to see this USB device listed in the device manager. The documentation seems to suggest that its something that will be automatically recognized however that is not happening. I have tried every USB port possible on my computer, have unplugged every other non-essential USB device and rebooted the computer several times. Am I missing a driver, some kind of firmware? If so where do I get it? The on-board LED lights seem to be indicating that it is receiving power and that the enumeration process was successful. At the moment i'm just trying to get AP Workbench open and get some kind of audio signal, however its not an option in the dropdown menu. What am I missing to get this recognized by the PC?

Posted on October 17, 2014 at 10:26Dear all,I working on a audio project where  a microphone memes array is used to record environmental audio. I want to use STEVAL-MKI126V1 and STEVAL-MKI138V1. On the datasheet for STEVAL-MKI138V1 I saw that such a board is recognized by a PC as a common USB audio card. Due to current setup that I already have, my wishes is to you use TEVAL-MKI126V1 and STEVAL-MKI138V1 not with a PC but with development boards such as BeagleBone. It is possible to create this kind of setup? It is sufficient that USB input of BeagleBone acts as a Master?Thanks in advance for the support, best regards,Rudy  #steval-mki126v1 #steval-mki138v

Posted on October 10, 2014 at 20:19Hi All,I'm trying to find either documentation, or example code on using the device drivers in STSW-MEMS031. Does something like this exist?  The ZIP file only contains the two C files and a header.Thanks!

Posted on October 14, 2014 at 15:32Hi,  I wonder if anyone can help with a sleep / interrupt problem?  When the sensor is awake and with the registers set for our application the device generates interrupts as expected.  If we change just the sleep register to put it in a low power mode the device never generates an interrupt again.  Is there a secret undocumented sleep sequence that we have to follow?Thanks.

Posted on October 11, 2014 at 13:30Hello, If LIS2DH12 ODR is set at 10Hz or 25Hz and if MCU reads its XYZ data with 10Hz rate (before reading, MCU does NOT poll any LIS2DH12 registers� status), is there any issue happened when MCU is reading the XYZ data during the period that LIS2DH12 is writing new XYZ data to the registers? Thanks. Ming #lis2dh12

Posted on October 08, 2014 at 05:21how to integrate ST�s pressure sensors and humidity sensors in Linux/Android systems?   #pressure-humidity-sensors

Posted on January 10, 2014 at 07:54I can't find a forum about barometric pressure sensor. I hope to know the wake up time of the chip from the power down to ready status for the measurement. I also need to know the measurement and conversion time for the highest resolution sampling. Or is there anyone else who can tell me where I should post this question.

Posted on October 08, 2014 at 14:09Hello How many bit does the data output of the LSM330 have? I can't find it in the datasheet. The register is 2x8 bit long, but are all bits valid? Regards Daniel #lsm330

Posted on October 08, 2014 at 09:04 I have a STM32F3-discovery board, and I have set up a little test. It just captures ALL input on GPIO3 and count them by channel. Then every seconds, I have a breakpoint with which I look at the numbers, and reset them. I am getting a correct number of interrupt, according to ODR setup, for the on-board sensor L3G4200D (channel 1) and for the mangetometer (DRDY, channel 2) part of http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/DM000275pdf. ButI can't make the accelerometer interrupt work. I've tried many ways, but basically I think the correct and most basic configuration should be: CTRL_REG1_A (20h), turn on sensor (ODR != 0)CTRL_REG3_A (22h), I1_DRDY1 bit to 1

Posted on September 02, 2014 at 17:05The sensitivity for this accelerometer is listed as 1mg/digit at +/-2g FS.  This brings up a few questions.  First, is a ''digit'' and LSB?? Second, at 16 bits, a LSB would be about 0.06 mg, not 1.0 mg.  There's something I'm not understanding.  What's the resolution of the ADC, and what's the ENOB of this accelerometer? #accelerometer

Posted on September 10, 2014 at 19:17Greetings -The LIS3DSH spec sheet says: ''Land pattern and soldering recommendations are available at www.st.com.''So far, I've not been able to find the info. Could someone please point me in a useful direction?Many thanksJim WagnerOregon Research Electronics #lis3dh-foot-print

Posted on May 22, 2014 at 09:08Is there more detailed spec on the temperature sensing of this part? In the data sheet it states +/- 2C from 0-80C. Is there a range where it is tighter?We are finding that room temp (~25C) we are on the high end +1.4C to + 1.7C on many of the production units. This is ''within spec'', but I'm wondering if it should be tighter at room temp. We have other temp sensors on the same board which do have a tighter spec of +/- 0.5C at room temp, but then go up to +/-2C at –40C and + 120C.</p> Also, we are seeing that the pressure sensor does not provide temperature values below about –25C, is this expected? The operating temp should be down to –40C. </span>

Posted on October 04, 2014 at 21:33How can we learn the noise densities for many of ST accelerometers? I am currently using analog LIS344ALH in my design, since it has a low noise density stated in datasheet. If intended to use a digital/SPI interface accelerometer, which product should I choose for same results?Thanks..