MEMS and sensors

Posted on June 24, 2013 at 19:58Hi,   I am trying to configure LIS3DH in FIFO/Stream mode and have a few questions as the data sheet is not very clear.1) Can I configure the INT2 as the WaterMark interrupt?  I don't see any option to configure INT2 as the interrupt in the register bits, although the spec seems to imply it is possible.  Our hardware has the INT2 pin connected to a GPIO, hence would like to know if configuring INT2 as the watermark interrupt is an option.2) Since I couldn't configure INT2, I went with polling the WTM bit of FIFO_SRC_REG to see if the watermark threshold level has reached (assuming WTM bit is the place to look for).  However, whenever I read FIFO_SRC_REG it comes out as 0.  I have enabled the FIFO in CTRL_REG5 (bit 6) and set the mode in FIFO_CTRL_REG.  What am I missing? Also, FIFO_SRC_REG doesn't have any explanation on what the reg bits mean.

Posted on June 24, 2013 at 18:40I have a design with the LSM303D e-Compass and 3D accelerometer.  When we calibrate the accelerometer, we are frequently seeing zero-g level offset corrections greater than the +/-60 milli-g typical value specified in the datasheet.Most assemblies that we calibrate are coming in around +/-60 milli-g in the X and Y directions, but we sometimes see numbers in excess of +/-120 milli-g in the Z direction.  Is the +/-60 milli-g specification intended to be a +/-1-sigma range?  +/-2-sigma?  Some other range?In the design, the part operates with a 3.0V supply.  How might one expect the offset accuracy to change with a 20% change from the nominal supply voltage? #lsm303d-accelerometer-offset

Posted on June 09, 2013 at 13:01Hi,I've been using an STM32F4 Discovery board with uVision4 for around 10 months now, and have learnt how to use the basic features (ADC, LCD, USART etc) and I'm now tackling the accelerometer (LIS302DL). I've looked at various examples from the net including the one(s) supplied by ST, however I always seem to get a HardFault Exception before main code is even reached! I've researched this HardFault error and tried to work my way around it, to no success. The Fault Report has NOCP ticked in the Usage Faults box and FORCED in the Hard Faults box.I've reloaded previous projects and they work fine. So it seems to be a problem whenever I try to write code relating to the accelerometer.Could someone please help me out? All I want to do is read from the accelerometer, and not encounter the HardFault Exception.ThanksTom #accelerometer #lis302dl #stm32f4

Posted on June 07, 2013 at 08:41I am trying to access the LSM330DLC devie using the SPI interface without luck. I have religiously tried to follow instructions in the part data sheet to read the WHO_AMI_G register but the there is no output on the SDO pin of the part when I perform a read over the SPI port. Here is how I have setup the part: * running the SPI clock at 3 Mhz * CS_G set low and CS_A set high Is there anything obvious I am missing? Also, I am trying to figure out the location of the source code for  iNEMO LI3 engine LITE. The online page for the resource on the STM website has a PDF for no source code. Can somebody point me to where I can find the code? Thanks in advance!

Posted on June 04, 2013 at 10:14libPDMFilter_IAR.a Does LibPDMFilter_IAR.a in the STMF4 DISCORVERY  is used for all STM32 family? for example, Is LibPDMFilter_IAR.a used for STM32F1XX not STM32F4XX????

Posted on May 07, 2013 at 18:05We have two LSM303DLHC on one board. Sometimes one of them appears to be stuck at -4096 on some axes. Even when I wave a magnet close to it doesn't change. The next day it's ok. The board was sitting on my desk all day. The datasheet says in presence of disturbing field ''Use S/R pulse to restore sensitivity'' How to do that? Is it done automatically? The compass range is set to 1.3 gauss. I can't think of anything on my desk that would generate such a magnetic field. The board draws only 1mA so it shouldn't be the current generating that. The strange thing is on the next day the compass works fine. Any suggestions? #saturation #-4096 #lsm303dlhc

Posted on May 03, 2013 at 06:25I am trying to get a gyroscope raw data using I2C. DEN_G is connected to MCU's GPIO and I set the register to use level trigger mode. I think I2C slave address is correct because when I read WHO_AM_I_G register I get 212 which is the same as default data in the datasheet. I do get a correct accel data but when I read the gyro data the data doesn't change when I move the chip. The gyro data is just a random variant number. So I checked CTRL setting register from register address 0x20 to 0x2D(Using multi byte read). All the CTRL registers had a same data as I set them. But I found out that when I disable the Y,Z-axis data(only enabling X) the OUT_Y_L,H OUT_Z_L,H still has a data. I think I am not reading the incorrect OUT X,Y,Z register because I used multi byte read method from 0x20 to 0x2D.(0x28~0x2D are OUT_X,Y,Z address). So can anyone give me an advice why setting CTRL register do

Posted on April 23, 2013 at 19:05Greetings,I'm trying to bring up an LSM303DLHC and I'm having trouble getting any form of interrupt out of the device.I've taken an STEVAL-MKI119v1 and removed the MKI108v2 and jumpered it to my I2C bus.  I have Vdd and VddA wired to a 3.3v source.  I can communicate over I2C with no trouble.  I can read the OUT_ regs and they seem to have reasonable looking data.I've set the device to sample at 30Hz.  I'd like to have it generate an interrupt on either DRDY or INT1 (or INT2) whenever new data is available. From looking at the MKI119v1 user docs (which contain the MKI108v2 schematics) there do not appear to be any pull-ups required on the interrupt pins.  It also seems that DRDY is wired to T3 though its unclear whether the R9 is populated with a 0-ohm resister.   Any hints on how to set the control regs to get a periodic data-r

Posted on April 12, 2013 at 14:42Is there a programming guide for LSM330? If there is one, could some one please post the link for that? #lsm330dl

Posted on April 12, 2013 at 11:06Hello,Accorting to datasheet, LIS331HH accelerometer don't have register WHO_AM_I. Is it possible to read identification data from 0xF register? What is identification value of LIS331HH? I need detect this accelerometer, because it has different full-scale value as for example LIS331DLH.this

Posted on April 08, 2013 at 22:36Hi all, I am new to the ST MEMS line, and recently purchased a few of the development boards to start testing (STEVAL MKI109V2, MKI120V1, and MKI115V1).  I followed the manuals for assembly and installing Unico, and have gotten the pressure sensor board to work over USB.  However, when I plug the Bluetooth module in and power up, the D2 LED on the BT module is barely lit and the device does not show up in a windows Bluetooth device scan.  It seems as though there is a fault somewhere in the BT module but I figured I would ask here before trying to RMA. Thanks, Jon #steval-mki115v1

Posted on April 08, 2013 at 14:28Hi, I am trying to read temperature values from OUT_ADC_3_H. I have also enabled BIT 6 and 7 in TempCfgReg and  Block Data Update, BDU  at CTRL_REG4(0x23). CTRL_REG1 is set to 100 Hz with value 0x57 running in normal mode. I always get 0x81 ~ -127 (2's complement) value in OUT_ADC_3_H. I running out of ideas. Any help or pointer would be helpfull. Best regards

Posted on April 01, 2013 at 16:19Hello.I use LIS3DH accelerometer with 4-wire SPI interface.I attached schematic of accelerometer connection (AccelSch.pdf).ACL_VDDIO = 3,3 VACL_VDD = 3,3 VOther ACL signals connect to microcontroller pins.R9A=R9B=R9C=R9D = 100 Ohm.When I configured accelerometer to work in 4-wire mode I saw that accelerometer send data on SDI pin 6. (SPI_Data_Transfer_4wires_Mode_Img1.jpg and SPI_Data_Transfer_4wires_Mode_Img2.jpg).Yellow signal - clock (SCL pin 4).Green signal - SDI pin 6 on net ACL_SDA/SDI/SDIO.When I configured accelerometer to work in 3-wire mode I saw that amplitude of signal on SDI pin 6 increased (SPI_Data_Transfer_3wires_Mode.jpg).Why accelerometer send data in 4-wire mode?

Posted on November 19, 2012 at 16:27Hi, I want to build an altimeter using LPS331AP sensor and after reading AN4159 I discovered that I should have software filter to have an accuracy of 0.02 mB required for altimetery. Do you know where to download such filters?MCU L�fter #lps331ap

Posted on July 31, 2012 at 12:14I can't quite work this out.  Someone tell me if I'm crazy.LSM303DLHC datasheet is somewhat difficult to read here.  I have CRB_REG_M set to 001, +/-1.3gauss, its most sensitive range.  But all its axes are not equally sensitive, the datasheet Table 75:Sensor input field range [Gauss] : +/- 1.3Gain X, Y, and Z[LSB/Gauss] : 1100  (the ''Z'' is surely a typo here, Z is described in the NEXT field)Gain Z[LSB/Gauss]: 980Output Range: 0xF800–0x07FF (-2048–2047)They're saying Z is actually less sensitive and has greater range, which is correct, the Z component of the Earth's magnetic field is actually significantly greater than the vector sum of the XY components.I am fairly certain I have correctly decoded the I2C registers.  X and Y are signed 2's compliment 16 bit ints, divided by 1100.  Z is divided by 980. &nbs

Posted on February 01, 2013 at 08:32I have a MKI-119V1 evaluation board and want to use the iNemo example application for IAR Embedded Workbench provided in..\iNEMO Suite\Firmware\iNEMO_Project\iNEMO_Project\iNEMO_EWARMBut after compiling and downloading with DfuSe Demonstration nothing happens and the usb connection is lost. If I have understood it correctly I should at least see a Led blinking by uncommenting the following line in main.c://#define TEST_ENABLECan anyone give me an explanation how this works: Is the the Dfu always located at address 0x8000000 and the application at 0x8003000?If I download a new application will it automatically be located at 0x8003000? Will the Dfu still be located at 0x8000000? Do I have to change anything in DfuSe?Do I have to build both the Dfu and the application and combine these to get it working?If anyone can give me a detailed explanation of how

Posted on January 05, 2013 at 10:15Hi, We are currently working on gait analysis using inemo V2. For real time processing we need to interface inemo with either matlab or labview. Can anyone please guide us for this interfacing?  #steval-mki062v2 #microcontroller-projects

Posted on December 07, 2012 at 11:55Dear Forum,i try use the maximum aquision frequency of 400Hz (acc, mag and gyro). My application is written in C++ (Visual Studio 2012, Windows 7) and i use the SDK for accessing the device content.Having a buffersize of >= 4 I only reach a datarate of about 270Hz. It looks like the serial interface is not able to handle that much data.Is it possible to increase the serial speed anyhow?Thank you very much!/Daniel(iNemo suite also does not handle the 400Hz)EDIT: My ''having buffersize >= 4'' may be misunderstood. Using a samplebuffer, that is smaller than 4, i reach a smaller frequency (down to 66Hz at buffersize=1). Raising the buffersize raises the frequency up to max. 270Hz .  #serial #baudrate #aquision #sdk

Posted on November 21, 2012 at 23:48Can the i2c output be used for maximum data rate or is SPI necessary to get full bandwidth out of this sensor?What is the meaning of ODR and BW in the data sheet? Thanks,Alex

Posted on November 16, 2012 at 22:22Hi all,is there anybody worked with LIS3DH accelerometer?i am very confused about axis value represeintation.when the scale is 8g, z axis value is 16 but the other axises are 255 in decimal.How can i represent these values as g value.Any data sheet or any suggest?

Posted on November 16, 2012 at 10:15Hi, I would know if it is possible to use the lps001 pressure sensor as altitude sensor? Does anyone tried this?MCU Lüfter

Posted on November 05, 2012 at 11:58I have the STEVAL-MKI062V2. I erased the original flash contents and downloaded my own code.Now I want to put again the old flash content to use with the iNEMO Suite application. I have the iNEMOV2_Firmware_PackageV2.2.0_AHRS.hex file but I don't find the right DFU.hex.The Computer doesn't recognize the USB interface and nothing works.Any ideas?Thx!

Posted on July 05, 2012 at 14:55The original post was too long to process during our migration. Please click on the attachment to read the original post.

Posted on October 24, 2012 at 18:01Good afternoon ...I'm using PIC16F886 with LSM303DLH and am only able to read the records, I am not able to write.For example: I am trying to write to the registry MR_REG_M, 0b0000000. But when I do the reading is appearing 0b00000011.What can it be? #lsm303dlm

Posted on September 13, 2012 at 07:51I am trying to calculate the heading of the 3 axis compass and stuck with this issue that I can't solve. when I read the compass output register viz.0x03 (x_msb),  0x04 (x_lsb),  0x05 (z_msb),  0x06 (z_lsb),  0x07 (y_msb) and  0x08 (y_lsb).  the  x,y and z MSB values are not updated at all where as y and z LSB are updated as expected. I configured the CRA_REG_M (00h) to  0x10 for 30Hz ODR,  MR_REG_M (02h) to 0x00 for continuous mode and CRB_REG_M (01h) to every possible value of (GN2,GN1,GN0) for all sensor rangebut had same result. I can't understand what the problem is, The I2C software seems to be fine as it works perfectly for accelerometer and gyro!!!!.did anyone come across this issue????sample output:Mxh=-16 Mxl=0 Myh=-1 Myl=