MEMS (sensors)

Posted on February 23, 2015 at 23:33In the LIS2DH datasheet Table 28., the mode with ODR<3:0> = 0x9 .Is it possible to set a ODR of 1344Hz at a 12 bit resolution?Is it possible to set a ODR of 1344Hz at a 10 bit resolution? #odr #lis2dh

Posted on September 08, 2014 at 17:37We are using LIS3DHTR in our design. Supply voltage is 3.3v.  Due to capacitors in our design, it takes some time for the 3.3v supply to drain out completely. So, when we turn off and on the unit, there is a chance that we may turn on the unit  while 3.3v supply rail is still draining out. During this, we observed that LIS3DH  lost its sensitivity and reporting close to zero acceleration on all 3 axis. Sensor remains in this state until we drain out the supply voltage. There is no problem with I2C communication. We receive the data. Control registers are untouched, we verify this by reading all the registers. Sensitivity was set to +/-2G. In a good working condition, the first 7 registers (0x00-0x06 reserved space) all reporting all zeros. But, in the other case where the sensor lost the sensitivity , the values are 0xFF, 0x30, 0x0F, 0x00

Posted on January 11, 2013 at 18:05Section 6.2 of the data sheet says that ''SPC,SDI,SDO are common'' however there are 2 different SDO pins, SDO_A and SDO_G. Has anyone tried connecting the two SDO pins on the target board?  Does anyone know if I2C mode always active when the CSx pin is HI? If so how do you prevent the I2C module for erroneously receiving a command from other devices that may be operating on the SPI bus? Thanks

Posted on February 12, 2015 at 16:24Hello I'm attempting to acquire continuous data at high rate from a LIS3DSH, and getting discontinuities in the data - any input / suggestions / feedback would be hugely appreciated.  The aim is full rate of 1600 S/s, but 800 S/s would be OK.  Only one channel is required (Y seems to be lowest noise).  The sensor is being communicated with over an I2C bus at 400 kHz.  Both FIFO and direct reading has been tried. - What is a sensible maximum data rate on a 400 kHz I2C bus? - Is it possible to use the FIFO and read only a single channel? - What is the most likely cause of discontinuities in the data - these seem weakly correlated with a larger number of elements in the buffer, but there is no evidence we are getting anywhere near the maximum 32 elements - see attached image Thanks! Aaron

Posted on February 16, 2015 at 12:03Hello, I have ordered samples of LIS2DH and its been a month I'm still waiting for the sample. My order number is 1079764. Please suggest what should I do, I have already tried the online support but I didn't received any response from them. Regards, Santu

Posted on February 12, 2015 at 23:511. On page 6, where it shows the orientation of the axis, does the arrow point in a way such that I should get positive readings by pointing them towards magnetic North? More specifically, what calibration procedure should I follow? I found this post, but what would really help is a step by step to find magnetic North: https://my.st.com/public/STe2ecommunities/mems_sensors/Lists/eCompasses/Flat.aspx?RootFolder=https%3a%2f%2fmy%2est%2ecom%2fpublic%2fSTe2ecommunities%2fmems_sensors%2fLists%2feCompasses%2fLIS3MDL%20offset&FolderCTID=0x01200200770978C69A1141439FE559EB459D75800050C48E6E10688F4B961EEC4647FF3FE1&currentviews=94. Thanks, never used a magnetometer before. 2. How is the DRDY (Data Ready) interrupt pin operate? How do I set/clear it? And do the threshold registers have any affect on DRDY?3. Not a question, but the register address map on page 23 has the INT

Posted on February 11, 2015 at 22:13On the lis2dh (SPI), I went through the data sheet and the very helpful application note AN3308, I was able to configure the lis2dh to detect idle and motion on the INT1. However, I am not able to make this work when FIFO mode is enabled in _REG5 and WTM enabled in _REG3, whenever I have this combination, the FIFO water-mark gets full and the WTM interrupt on INT1 gets generated as expected.So, is there a way to avoid generation of WTM when the OUT_X/Y/Z are within a certain threshold ? #lis2dh-wake-up-motion-detect

Posted on February 09, 2015 at 17:51Cross post from the gyro forum (didn't realize it was in the wrong spot).Hi All, I need some advice/help getting my gyro calibration.  I'm using the X-NUCLEO-IKS01A1 board to evaluate the LSMDS0 gyro.The raw data that's coming from the LSM6DS0 doesn't seem to be DPS, the values are much to high for the range specified in the data sheet.  Is there some formula I have to apply to it?Also, I'm prepping the code and documentation for our production team to use the LSM6DS0 in their product, but the calibration routine will have to be done.  There are several documents provided by STM that outline the technique required for calibration after the LSM6DS0 is mounted on the IC and installed in the device.     But I haven't found one exactly for the LSM6DS0.TLDR: I need help setting up the calibration and

Posted on May 26, 2014 at 09:10What are the basic features of VL6180X ? #vl6180x #features

Posted on February 20, 2014 at 20:35Hello Folks,Not sure where else to post this as there doesn't seem to be any subcategory for pressure sensors in the sensors category, so I'm posting it here, please forgive any offense on that count.We've been working with the LPS331AP on a couple of designs and only on a recent board spin have we noticed this issue on a number of units.  The circuit we're using is identical to that detailed in the datasheet.  The device is configured in I2C communications mode, with the resolution set to 0.025 mbar, the internal averaging for both temp and pressure set to 1, continuous mode rates set for 25 Hz for both temperature and pressu

Posted on February 05, 2015 at 09:01 .ExternalClass8B0DBA798B5B4AA8BE4D83498BC56468 p {margin-bottom:0.25cm;line-height:120%;} .ExternalClass8B0DBA798B5B4AA8BE4D83498BC56468 a:link {;} Hello,I use the accelerometer LIS331DLH but I have a problem about values.The MEMS is conect to the card Mbed FRDM-K64F, 3,3V supply and SPI bus communication.I use this datasheet :http://www.st.com/web/en/resource/technical/document/datasheet/CD00213470.pdf and this application note http://www.st.com/web/en/resource/technical/document/application_note/CD00215823.pdfCommunication is OK, WHO_I_AM returns 0x32.In my program, I follow th

Posted on October 22, 2013 at 07:57I'm having trouble getting i2c communications working with LSM9DS0 iNEMO inertial module.  I've wired it up, but it isn't responding to who_am_i read request.  I've wired SDO to 1, so am using your default i2c address 0x3A, but I'm getting no slave ACK signals.  Out of desperation wondering if I had the address wrong I pinged every i2c address, and still found no response.  I've tried 100 kHz and 400 kHz, same result.  I've also wired different i2c sensors, and they work fine, so I know the rest of my board works.  Are there any tricks getting i2c to work?

Posted on January 30, 2015 at 10:54Hi, I am trying to get hold of a copy of Unico to help me debug a state machine in an LIS3DSH. I have filled in the request online a number of times, and even though the request to download has been approved each time, when I click on the download link, it says that there is no file there. Any assistance would be appreciated. Thanks, Andy Pevy #lis3dsh #unico #state-machine.

Posted on January 29, 2015 at 10:45I am trying to sense angle, and i am using LIS344ALH analog mems. I achieved zero g level and sensivity calibration, but i can not achieve making temperature calibration. g value changes with temperature very fast.How can i make this temperature calibration ?I need your help, thanksBest Regards from T�rkiyeMehmet #mems-temperature-calibration

Posted on January 28, 2015 at 08:55Hi All,I read thru UM1049 Unico GUI: software guide but don't clarify the operating mode clearly.For Operating Mode, there have low power(1Hz-5kHz) and normal power(1Hz-1.6kHz).How to select the compatibility operating mode?

Posted on January 27, 2015 at 06:47 1) Question1 I am reading the the data sheet of LIS3DH AN3308.  I doubt about the description of 3.2.3(Example of accleration data).350(0x15E)mg register data is Val_0x29 = 0x15, Val_0x28 = E0 (left-justified)It is OK of BLE1g(0x400mg) register data is Val_0x29 = 0x04, Val_0x28 = 0x00Is it correct example?? I think it should be  Val_0x29 = 0x40, Val_0x28 = 0x002) I download LIS3DH driver code from st.com stsw-mems023_LIS3DH Linux OS device driver.zipthe get acceleration data code is as the following, acc_data[0] = (AXISDATA_REG);  err = lis3dh_acc_i2c_read(stat, acc_data, 6); hw_d[0] = (((s16) ((acc_data[1] << 8) | acc_data[0])) >> 4); hw_d[1] = (((s16) ((acc_data[3] << 8) | acc_data[2])) >> 4); hw_d[2] = (((s16) ((acc_data[5] << 8) |

Posted on November 06, 2014 at 05:43I have been having some trouble getting up and running with the LPS331AP. Using a logic analyzer, I've verified that the sequence of commands given in AN4159 section 5.1.1 (one shot mode measurement sequence) is being sent to the device. However, when I retrieve a measurement from the sensor, the 2-byte temperature measurement is always CC CC and the 3-byte pressure measurement is always 6D 6D 6D. The sensor takes about 40 ms to return this answer, so it seems that the update rate is correct at least.AN4159 section 6.2.2 also mentions the existence of ''a list of C source files that provide the baseline in initializing, configuring and performing measurements with the pressure sensor.'' However, I have not been able to find these files. If anyone knows where I can find these, I think the might be a big help in eliminating potential errors.Alternatively, if the problem I've desc

Posted on January 27, 2015 at 09:55What is LSM9DS0  gyro accuracy? (bias instability, Allan variance, etc..) In this forum http://forum.taulabs.org/viewtopic.php?f=22&t=200 the user http://forum.taulabs.org/memberlist.php?mode=viewprofile&u=108 said the LSM9DS0/1 have a bias stability of 20 deg/hour. Is it true? I belive that accuracy is of the order of  200 deg/hour. Can anyone help me?

Posted on January 22, 2015 at 14:55Hi all, I'm currently evaluating the LIS3DSH for an integration in a multi-sensor monitoring system. I need to enforce synchronization of sampling between all the digitals sensors of the system but I didn't found any mention to a way to do so in the datasheet of the component (for an example a start pin). Maybe I missed it ... Does any body has any idea if it is possible with this chip (or with another one) and how to do it ? Many thanks Timoth� #lis3dsh #sampling #synchro

Posted on November 17, 2014 at 11:45I get wrong accelerometer's values. I have concatenated xMSB+xLSB, yMSB+yLSB and zMSB+zLSB. Then I verify if the resulting valor is negative, in such case I substract 2^16 to convert from 2's complement number to decimal. Finally I multiply each axis valor by 0.00006 to obtain acceleration values in g units. What I'm doing wrong? What is the effective number of bits? Thanks!

Posted on November 26, 2014 at 06:40Hi I configured the LSM303DLHC accelerometer as follows. CTRL_REG1_A with 0x77  //400hz data CTRL_REG4_A with 0x00 //Little endian And started reading the data from the OUT_X / Y/ Z_L / H_A registers. But I could find something that the lower nibble was found to be zero all the time in the  OUT_X_L_A, OUT_Y_L_A, OUT_Z_L_A registers. So is the data in LSM303 12bit left justified or am I missing something? Note: In datasheet i found it is 16bit but in some driver samples the values of the data registers are combined and right shifted by 4 bits (I assume this is to compensate the left justified data) Regards HpC #lsm303dlhc-data-format #lsm303dlhc

Posted on November 07, 2014 at 08:45Hi everyone,this is my SPI configuration used for interfacing with the LSM9DS0 in 4 wire RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2 , ENABLE);    SPI_InitStruct.SPI_Direction = SPI_Direction_2Lines_FullDuplex;    SPI_InitStruct.SPI_Mode = SPI_Mode_Master;    SPI_InitStruct.SPI_DataSize = SPI_DataSize_8b;     SPI_InitStruct.SPI_CPOL = SPI_CPOL_High;     SPI_InitStruct.SPI_CPHA = SPI_CPHA_1Edge;    SPI_InitStruct.SPI_NSS = SPI_NSS_Soft;    SPI_InitStruct.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_32;    SPI_InitStruct.SPI_FirstBit = SPI_FirstBit_MSB;    SPI_CalculateCRC(SPI2, DISABLE);    SPI_Init(SPI2, &SPI_InitStruct);   SPI_SSOutputCmd(SPI2,DISABLE);   SPI

Posted on January 19, 2015 at 16:24I can get the STEVAL-MKI121V1 to work under Windows via the Inemo SDK. I would like to have a similar setup under linux. Is there a driver (module) and SDK available to do the same?What would be the fastest and easiest way to obtain data from a Linux client over USB?Kind regards,Anouar Manders #linux

Posted on January 16, 2015 at 13:28Hello.What i am trying to do - is to synchronize all inertial sensors (accel, gyro, mag). Each of these sensors has its own FIFO buffer.I did not encounter any problems with magnetometer and accelerometer, in contrast to l3gd20 gyroscope. The main problem is number of samples in FIFO buffer, it is never 0 (even if i read FIFO Sample number register every 2 ms, while the sample rate of the sensor is 95Hz).My steps:Gyroscope configuration (95 Hz sample rate, FIFO mode - stream).When i am reading gyroscope data i read number of samples in the following way:int sample_number;i2cread(L3GD20_ADDR, 0x2F, &sample_number);if (sample_number & 0x20) return 0;else         return (int)e_n & 0x1f + 1;Does anyone have any suggestions regarding my issue? What is the reason that the FIFO is neve

Posted on January 12, 2015 at 16:48Hi, I'm runnig a small research project with the STEVAL-MKI117V1 evaluation board. At the moment I'm facing some problems with accessing the audio data stream. Hopefully someone can answer my questions: 1. Is it possible to connect directly to the STEVAL-MKI117V1 with the APWorkbench or do I need another eavaluation board? At the moment I'm receiving a FTDI error message, which can be seen in the attached image, although the ''CDM v2.12.00 WHQL Certified'' FTDI driver is aready installed. 2. I tried to access the audio data through the I2S interface at the APWlink+ connector. Unfortunately ''I2S_DAT_12'' is always low and ''I2S_BICK'' and ''I2S_LRCK'' are always high, so no data is transmitted. 3. Is it possible to get access to the STM32F107RC microcontroller? Kind regards Marc