MEMS and sensors

Posted on March 28, 2014 at 03:13Hello, I am new to ST accelerometers.And I am interested to LIS3DE or LIS3DH.I would like to know the mechanism of the self-testing mode.Anyone can help to send me a link of ST site, so I can learn from that?I tried to search by my self, but all are information of products, no explanation on the mechanisms.I read some other documents on internet, that the self test of some others accelerometers,A electrostatic test force is applied to the mechanical sensing element , so the self-test actually is almost same as you move the sensor in reality.So I want to know if ST 's Accelerometer works in same way. #self-test-self-testing-mechanism

Posted on March 21, 2014 at 14:34Hello,I am using accelerometer LSM303DLHC.I have made following settings:-1)      2g mode and data rate of 25Hz in normal mode.2)      All configuration register set as per initial requirement of accelerometer.3)      Interrupt on INT1 pin is set. For this CTRL_REG3_A is set to 0x40 value .4)      Threshold sets at 25 in INT1_THS_A register.5)      And  INT1_CFG_A  is set to 0x0A (interrupt on X and y Axis high event)After interrupt occurred measured all axis data and INT1_SRC_A register to know for what reason interrupt occurred.One reading from it is as X: FF00Y: FCE0Z: 39D0INT1_SRC_A: 6AINT1_SR

Posted on January 29, 2014 at 18:47Hi,after installing and compiling the iNemo Libraries, I wanted to know if there are any code samples relating the M1 module, even simple ones.Thank you #inemo-m1-sample-code

Posted on March 20, 2014 at 15:26Hello,I'm trying to work with LIS3DSH device with different ranges.I put the device on a table facing up, so Z axis should give me 1000mg reading, for all ranges.I configure the device to range 2g by writing to reg_5 0x00The raw value I got was 0x3ffe.The sensitivity for this range is 0.06mg/digit according to spec,So calculation is: 0x3ffe * 0.06 = 982.92 mg , close enough to 1000mg.I flipped the device to measure negative value.The raw value I got was 0xc001. according to spec I calculated 2's compelemt:0xc001 -> 2's complement -> 0x3fffSo calculation is: (-1) * 0x3fff * 0.06 = -982.98 mg , close enough to -1000mg.Then I tried to change range to 4g by writing to reg_5 0x08 (flipped the device back).The raw value I got was very similar to the previous one 0x4002.The sensitivity for this range i

Posted on March 20, 2014 at 08:48Dear sir/Madam, we are using lsm303dlhc. we don't know how to do calibrations .we are not understanding scale factor , offset and misalignment . so , i request you please give me the clear information regarding this issues. what are the formulas need to use calibrate the raw from sensor. Regards srinivas

Posted on March 19, 2014 at 17:25Hi,I am new to STM32 F3 Discovery. Wondering if this board can configure to support Windows 7/8 sensor and location platform. I am trying to figure out how to set it up to use Microsoft inbox driver.Thanks,Dick #stm32-f3-discovery

Posted on March 18, 2014 at 13:57we are  working with lsm303dlhc compass sensor and  interfacing with lpc3250. we are using linux kernel version 2.6.34. and have taken driver codes (accelerometer and magnetometer) from your site. its working only one particular direction with 0 to 360 degrees angles. remaning directions its giving only 250 to 360 degrees angles only. i mentioned below what are calculations are using accelValue[0]= accx/sqrt((accx*accx)+(accy*accy)+(accz*accz));     accelValue[1]= accy/sqrt((accx*accx)+(accy*accy)+(accz*accz));   pitch = asin(-accelValue[0]);   roll = asin(accelValue[1]/cos(pitch)); xh = magx * cos(pitch) + magz * sin(pitch);   yh = magx * sin(roll) * sin(pitch) + magy * cos(roll) - magz * sin(roll) * cos(pitch);  heading = 180*atan2(yh,xh)/PI; so, i request you can give me any sugge

Posted on March 18, 2014 at 13:54we are  working with lsm303dlhc compass sensor and  interfacing with lpc3250. we are using linux kernel version 2.6.34. and have taken driver codes (accelerometer and magnetometer) from your site. its working only one particular direction with 0 to 360 degrees angles. remaning directions its giving only 250 to 360 degrees angles only. i mentioned below what are calculations are using accelValue[0]= accx/sqrt((accx*accx)+(accy*accy)+(accz*accz));     accelValue[1]= accy/sqrt((accx*accx)+(accy*accy)+(accz*accz));   pitch = asin(-accelValue[0]);   roll = asin(accelValue[1]/cos(pitch)); xh = magx * cos(pitch) + magz * sin(pitch);   yh = magx * sin(roll) * sin(pitch) + magy * cos(roll) - magz * sin(roll) * cos(pitch);  heading = 180*atan2(yh,xh)/PI; so, i request you can give me any sugge

Posted on March 18, 2014 at 10:25Hello, can you please shift your datasheet to the level of both of this below at least ? http://www.st.com/web/en/resource/technical/document/application_note/CD00290365.pdf http://www.st.com/web/en/resource/technical/document/application_note/CD00215823.pdf First, in this is stated, that ''data-ready'' signal is reset after higher part of the data of all the enabled channels has been read. There are many questions in this forum... Second, I could read, that data is left justified. But why not in the right datasheet? But third, please answer tickets(!) and forum questions

Posted on March 17, 2014 at 20:19I have an application where the ST Micro part LSM303DLHC has been specified for a product which has a -50C storage requirement. This ST Micro e-compass is only rated down to -40C for storage (and operation). We are also looking at the LSM303D as the LSM303DLHC is marked as not recommended for new designs. Can anyone from ST Micro comments on the potential damage to this part at temperatures below -40C? Thanks, Peter

Posted on March 17, 2014 at 20:17I have an application where this ST Micro part (L3GD20)  has been specified for a product which has a -50C storage requirement. This ST Micro gyro is only rated down to -40C for storage (and operation). Can anyone from ST Micro comments on the potential damage to this part at temperatures below -40C? Thanks, Peter

Posted on March 14, 2014 at 16:11Hi, How can I get answers from you? Next try. This is a typical sequence with FS=00 and DR=11 and the chip lying on the table. How do you review this? Your spec says TyOff +-1g, and So=0.049. Where does this noise came from ( +3g on Z-Axis) ACCELERATION    ff70 ffd0 2c0   -0.439453 -0.146484 2.148438 ACCELERATION    fec0 fff0 190   -0.976563 -0.048828 1.220703 ACCELERATION    ff20 090 490    -0.683594 0.439453 3.564453 ACCELERATION    fff0 020 320    -0.048828 0.097656 2.441406 ACCELERATION    ffc0 0a0 20     -0.195313 0.488281 1.562500 ACCELERATION    ffe0 040 260    -0.097656 0.195313 1.855469 ACCELERATION    ff60 ffb0 250   -0.488281 -

Posted on March 14, 2014 at 14:55Maybe I'm dumb but I can't figure it out myself - I can't find download  links for iNEMO Engine Lite. http://www.st.com/web/catalog/tools/FM147/CL1818/SC1528/PF260129♯ this link just tells me that status is ''preview''. The same goes for all iNEMO software, I can't see any kind of download link or how to order instruction. Am I doing something wrong? #inemo

Posted on March 12, 2014 at 10:28Couple of questions ...1.  I have typically seen LIS3DH paired with Cortex M3 for e.g. in most of the health/fitness monitors. Is M3 required or could we use a M0/M0+. In other words what is the uC bandwidth required for ensuring no samples are dropped.As per my calculation M0 should be sufficient and M3 has been used in those products to support DISPLAY and/or USB. Could some one confirm ? 2. Further on does LIS3DH require a dedicated microcontroller or can it be shared with a uC (MSP430/8051/Cortex M0) which is part of say the Bluetooth connectivity SoC ? #lis3dh #microcontroller

Posted on December 21, 2013 at 21:50Hi, i'm a german student and i'm working on a private project. It's a UAV (UnmannedAirVehicle), which controls it's altitude by pressure. For this, i want to use a LPS331AP, but the raw-data output oscilates with a frequency of about 0.05 Hz. Normally, i would use a bandstop filter to reduce / minimize this noise, but if the UAV moves up or down, the frequency can be / will be often the same, so this doesn't fit. In the application note ''Hardware and software guidlines'' it says on page 16: '' For indoor navigation when sub meter detection is required, a special recursive filter could be used. Tailoring the S/W filter for the sensor characteristic and the application requirement is usually a good move. Sensor fusion is the most advanced filtering which uses all available information and uses them to reduce the positioning noise. '' But i can't find any

Posted on March 06, 2014 at 21:21Short of removing and reapplying power, is there a way to reset an LSM303DLCH?  I'm having an issue where some device on the I2C bus is driving the SCLK low after a reset of the host processor, making it impossible to communicate with any devices after that.  The only way to clear the problem at that point is to cycle power on the system.  I don't know which device is driving the bus low, but there are only two options; the LSM303 or a Maxim RTC.  I'm hoping to get to the bottom of this issue and prevent it from happening in the future, but as a failsafe I'd like to be able to reset the devices if this condition is ever detected.  I'm a software guy, so maybe I overlooked something obvious in the data sheet, but I don't see an sort of reset line.  Thanks,John

Posted on March 06, 2014 at 11:08Hello, Please give me information about the following questions. 1. What is the sensibility of the LIS331DLH accelerometer sensor? 2. What is the minimum acceleration that LIS331DLH can detect? Is there anyone who can tell me clearly about the above two questions? Please.

Posted on February 27, 2014 at 11:27What are the recommended soldering parameters (i.e. solder paste thickness) for MEMS microphone manufacturing?

Posted on March 04, 2014 at 17:58 There is a linux sysfs file for accessing data from LIS331DLH. cat /sys/devices/platform/lis3lv02d/position What does this actually retrieve. Cartesian co-ordinates? If yes, with respect to what? Can this be used for ''Inertial navigation'' ? Or it is actually acceleration data itself? Kiran G #lis331dlh #position

Posted on March 03, 2014 at 22:56There is  a low pass filters LPF1 which is after ADC(page 22 of the data sheet Doc ID 022162 Rev 2 ).There is no words about this filter can anybody tell me a bit more about it? for example what is the cut off frequency, what's the order? What kind of low pass filter? My sample rate is 760Hz. Thanks in advance.

Posted on March 03, 2014 at 08:43I have calculated Tilt/Gradient in Non-accelerated systems(System acceleration  = 0); How to measure Tilt/Gradient in accelerated systems.As MEMS will give the X,Y,Z component of the resultant acceleration(g and a ).Also bike acceleration(Both magnitude and direction) cannot be predicted.Simply,How to seperate sytem acceleration(a) from g(Acceleration due to gravity). Please suggest over this point.

Posted on March 01, 2014 at 10:23HelloI have read that impact detection functionality can be performed by LIS3DH. I am unable to find any information on HOW to configure the device for impact detection.Is it identical to ''click'' detection? If no - than how to configure device for impact detection? #lis3dh

Posted on February 27, 2014 at 23:51I am using an Aardvark SPI/I2C USB adapter and a Labview VI I have written to acquire accelerometer data from the STEVAL-MKI122V1(LSM330DLC).  I am noticing at an output data rate of 1Hz, the OUT_X_L_A, OUT_X_H_A, OUT_Y_L_A, OUT_Y_H_A, OUT_Z_L_A, and OUT_Z_H_A registers do not update at the same rate.  There are times when the X and Y Axis registers update and the Z Axis registers remain the same and vice versa.  What is the best way to acquire accelerometer sensor data and ensure the desired output data rate stays intact without using the FIFO?  Or is the FIFO the best way to go? 

Posted on February 27, 2014 at 23:34I have acquired both the STEVAL-MKI122V1(LSM330DLC) and the STEVAL-MKI109V1(eMotions Motherboard) and have been using them together for some time now.  But now, I want to use the STEVAL-MKI122V1(LSM330DLC) by itself and I have figured out a way to power it and want to make sure I am powering up the LSM330DLC correctly and I am not damaging the device.  I am currently applying 3V to pins 1 and 2 of the JP1 header.  I am applying the Ground to pin 13 of JP2 header.  Is this configuration correct? #lsm330dlc #steval-mki122v1

Posted on February 26, 2014 at 11:06I've set up the LSM9DS0 to the +/-16g range by setting AFS2 - 0 as 100 as per datasheet. Normal g comes out as 0.7g, yet all other ranges are fine. What am I doing wrong? Chris