MEMS and sensors

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..

Posted on July 17, 2014 at 17:33Hi guys,I'm using the LSM330DLC on a weareable device, but while testing I noticed that while measuring the gravity I get values on Z axis around 1380 counts (0x0564 hex raw data coming from the ic).The configuration is set to:Normal Mode (tried both enabling and disabling high resolution in CTR_REG4)Full Scale +-16GSampling rate 100Hz.So my question is:Datasheets says that normal mode high resolution involves a 12bit data conversion (table 9 page 20). If so, measuring gravity should give us around 128 counts and while measuring 16g we should get 0x0fff (16bit coming out of the spi/i2c interphase).This means that we are not working with 12 bits definitely. So making some numbers it makes no sense to obtain values around 1400 counts while measuring gravity (without moving the device). Because this number times 16 does not m

Posted on September 25, 2014 at 13:32if LIS3DH interrupt output floating or connect to very high impedance device, what is the current consumption when interrupt is enable? Is the device consume 100 over uA when interrupt is enabled? #lis3dh #lis3dh-interrupt

Posted on September 24, 2014 at 20:38Hello,I recently received a LIS3MDL board for evaluation.  After successfully implementing communications over I2C and receiving good data, it recently started misbehaving.  I am unable to read any data from the X, Y, Z, or temperature data registers.  When monitoring any of the XYZ status bits in the status register, none ever reach a set state.  Does anyone have suggestions on where to go from here?Thank you,Ryan #e-compass #amr #3-axis #lis3mdl

Posted on September 07, 2013 at 18:15What are the differences between the L3GD20 FIFO and the LIS3DH accelerometer FIFO? #lis3dh #l3gd20

Posted on September 23, 2014 at 16:57Is it possible not supplying VDDIO while INT1 and INT2 remain active? The Datasheet doesn't give information about that.Regards,Arne Kr�ger #lis331dlh-sensor

Posted on July 11, 2014 at 09:32Hello,I have a problem about EXTI settings in iNemo sample application LSM303DLHC_AccDataReady.c. My function EXTI9_5_IRQHandler defined in main.c is never called. I would like to know if some parameters should be set in startup_stm32f10x_hd.c. In fact I don't want default interrupt function to be called, but mine. Thank you in advance for your help!

Posted on September 20, 2014 at 20:56 I bought the iNEMO-M1 Discovery and I'm compiling a program that reads magnetometer values. If I do: trace_printf(''test %f\r\n'', 40.678); It prints ''test '', and no value (not even 0). If I do: trace_printf(''test %u\r\n'', 40.678); It prints ''test 1''. I'm using Eclipse with the GCC library, and the ST-Link/v2. Edit: resolved, it was a problem with Newlib-nano library.

Posted on June 03, 2014 at 18:37Hello!I'm trying to obtain correct data using I2C interface from magnetometer lsm303dlhc, which is included on mu stm32f3discovery board. I've configured device for continous conversion mode, 30Hz data output rate and scale 1.3 Gauss. My aim is to get simple information about placement from north (angle from north pole). To make this real i'm counting angle beetwen measured values of y and x dimension [atan2(mag_y, mag_x)]. Unfortunatelly i'm getting unexpected results - i.e. rotating 90 degrees equal 120 degrees or 60 deegress, depends on board placement (boards is lying on the table all the time). This results are repeatable, so i think that device is working with some kind of non-linear scale, which i can't determine. Weird is fact that this is board from st and imo it should work with any problems. I programmed my second board and situation is simmilar. What should i do to make this device work proper

Posted on September 19, 2014 at 08:04Hi,I am writing code for LSM6DS0 module.I could not find any reference driver or Initial setting needs to be done .In the datasheet there are two modes : (1) Accelerometer active and Gyro Inactive(2) Accelerometer active and Gyro activeIs there no way to power down both.As a thumb rule I will set the ODR and enable the Power ON mode.Apart from this is there any special settings needs to be done like BDU,HP filters,FIFO, etc for this module.Initially I just aim to read the sensor data of Accelerometer and Gyroscopes andlookign for minimal settings to be done.Any special settings needs to be done.Please suggest.rgds,R #lsm6ds0 #gyroscopes #accelerometer

Posted on September 10, 2014 at 21:09What is expected zero-g drift at ambient after Temp cycle? #lis344alh

Posted on August 27, 2014 at 08:35I want to utilize command in STEVAL-MKI109V1 board.  STEVAL-MKI108V1 is insert on the  STEVAL-MKI109V1 board, I utilize user guide to set up. Bur terminal can't receive any data? How do I slove the problem? #mki109v1 #mki108v1

Posted on September 05, 2014 at 16:24 I'm struggling to understand the correct method/formula to convert the digital reading of the accelerometer to G units (LIS2DH). The data sheet states that The value is expressed as two’s complement left justified. I have the sensor running in high resolution mode. I'm not sure if my formula is correct as well. #define SENSITIVITY 0.001#define OG_OFFSET 0.50 unsigned int X_16BIT_AXIS2 = (X_16BIT_AXIS >>4); char G_X_AXIS = SENSITIVITY*(X_16BIT_AXIS2-OG_OFFSET); #lis2dh

Posted on July 09, 2014 at 15:47I received some results from LIS3MDL.I tried to measure the magnetic field of the Earth = 0.05 mT = 0.5gauss. Full scale setting = �4gauss. If I rotate the magnetometer Y axis towards the north I receive 0xF3E0 (-3104) = -0.45gauss, if  rotate Y towards south - 0xECAB (-4949) = -0.72gauss. If I rotate X axis towards north - 0x1288 (4744) = 0.69 gauss, X towards south -> 0x0B2E = 0,41 gauss.Where did this offset means?Maybe I missed something? #lis3mdl-offset

Posted on August 28, 2014 at 19:21I have a question pertaining to the drive strength of the analog outputs of the LPY410AL 2-axis analog gyroscope. The circuit is as follows: The analog outputs of the LPY410AL are connected to the inputs of a LMV324 Quad Op-amp in unity-gain configuration. The outputs of the op-amp are connected to the inputs of a ADS8332 Analog-Digital converter. Each digital output is then connected to an I/O pin on a Lattice XP2-8E FPGA. My question is: are the op-amp buffers required between the gyroscope and the ADC? They were placed as a precaution as we were unsure that the drive strength of the gyroscopes was enough for the ADC. We are now looking to shrink down the size of the board by removing the op-amps. If you have any other questions or require more details, please let me know.Thank you,Dan #imu #gyroscopes #lpy410al

Posted on August 28, 2014 at 16:25I am using both state machines on the LIS3DSH to analyze two different types of movement. I only have room to use a single INT pin, so I am trying to direct both state machines to it running at the same time. When the interrupt triggers, is there any way to tell which state machine was the one that triggered the interrupt? I can not find a register that contains a flag showing whether a machine has been triggered. Thanks for the help! #lis3dsh

Posted on August 27, 2014 at 07:32 Hello! We want to use your evaluation algorithm of calculation Kalman's filter. In order to evaluate it work we want to apply in input of the filter data not from chip but generated . In which formats should this data be? You can show ( in example) what should be the data on three axes ? Thanks.

Posted on August 21, 2014 at 14:11Hi!I am using the LIS331DLH sensor in my project. I have no problem with processing between CPU and sensor via SPI. But I cannot communicate them via I2C - all registers are return 00 when reading.Here is the part of my code that describes W/R process of sensor, and oscillogramm of I2C bus.Thanks. #lis331dlh