MEMS and sensors

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

Posted on October 09, 2013 at 10:07Hi guys,I just received a couple of iNemo M1 boards (http://www.st.com/web/en/catalog/sense_power/FM89/SC1448/PF253162). It's a nice little gem, and I look forward to design great stuff with it. However I have not managed to talk to it yet. So far I managed to upload iNEMOV2_Firmware_PackageV2.2.0_AHRS through USART, but I got no data when listening, and it was not recognized by the demo application.Looks like there are: iNEMOEngine_PW8, iNEMOEngine_Ll3, iNEMOEngine_PAAP and iNEMOEngine_Pl3P, but I could not find the files� Moreover my goal is to change the firmware, so I believe I need the Light version provided with sources.So in brief, is there a working firmware and demos somewhere? Is there firmware example sources somewhere? Should I use a different communication port?Thank you very much #inemo-m1-firmware-demos-source

Posted on January 08, 2015 at 16:43 Hi all, I have to connect the LPS25H sensor with the steval-mki062v2 board through the onboard 10-pin connector J8 and use the SPI1 for communication; I want to use the same iNEMO firmware provided with the board except for the onboard pressure sensor data, wich have to be replaced with the external sensor one. I wrote the library for the spi communication but nothing works. With the oscilloscope I don't see any signal from the connector except for the power. My code below: ''HAL_LPS25H.h'' /* Define to prevent recursive inclusion -------------------------------------*/ #ifndef __HAL_LPS25H_H #define __HAL_LPS25H_H /* Includes ------------------------------------------------------------------*/ #include ''stm32f10x.h'' #include ''iNEMO_conf.h'' /* LPS25H SPI defines */ #define PRESS_SPI SPI1 #define PRESS_RCC_Periph_SPI RCC_APB2Periph_SPI1 #define PRESS_SPI_Port GPIOA #define PRESS_SPI_CS_Pin GP

Posted on January 07, 2015 at 18:05I have read and re-read the data sheet on this device. In sleep mode for the gyro and active mode (50 Hz) for the accelerometer I expect a current consumption of 5 + 11 = 16uA. In reality I measure 120uA - 140 uA. (depending on sample). I use the I2C interface, all inputs and outputs are properly connected to the uP. Pins 1-5, 24,25 and 28 are connected to ground, pins 6-13, 19,20,21and 23 are connected to 3.3V. The unit functions correctly. If I put the accelerometer to sleep the consumption drops by 10uA, as expected. I appreciate any help or suggestion anyone could give. I have googled and found nothing. What am I doing wrong??? Please help #sleep-current-lsm330d

Posted on January 06, 2015 at 07:22The original post was too long to process during our migration. Please click on the attachment to read the original post.

Posted on December 30, 2014 at 01:43Well, the subject line says it all really. There is no download link on the ST iNEMOEng_M1LI3 web page, so where do we get it from? Thanks.

Posted on January 01, 2016 at 18:23Dear Community, I'm implementing a design with LSM9DS0 in SPI communication mode I have a question about the following CS pins 19 CS_G 20 CS_XM Did they work as normal CS SPI Pins or I just to pull them to 0? BR M

Posted on December 28, 2014 at 20:21Hey,For my project I need the highest output data rate/bandwidth possible. I also need to sense high g impacts (>100g). Currently I am using the H3LIS331DL and getting 1KHz output data rate with +-100g/250g range.Does anyone know any accelerometers with a higher bandwidth? Would I get more bandwidth using an analog sensor rather than digital. (From what I have found it doesnt seem I would). Thanks! #accelerometer-bandwidth-rate-odr

Posted on December 27, 2014 at 19:22Is there an updated data sheet for LSM303DLHC? In datasheet DocID018771 Rev 2 some informations once covered in former products just have been dropped. Such as ADC conversion range / scaling of measurement values.Single conversion mode is not covered.Register locking is not explained.Please point me to some updated specifications / datasheets. Jean #datasheet #lsm303dlhc

Posted on December 18, 2014 at 06:49I purchased a STEVAL-MKI109V2 and it did not come with any software.  After some searching of the web site I found the user guide and some software guides but no actual software.  I found a software page for http://www.st.com/web/en/catalog/tools/PF261470 which appears to be the correct software but there is no download. .  I also have the STEVAL-MKI137 to evaluate the LIS3MDL.  So now I have a board that has a pretty blue light but is not really helping to evaluate the sensor that I am interested in.  Hope to get some diretction. #steval-mki109v2

Posted on October 04, 2013 at 16:39Hello, I'm hoping to get a bit of guidance here on this application I'm developing using the LIS331HH device. I have integrated it into the application PCB, and using SPI to communicate with the device. All is well and I can set and read registers, ODR, filters, range, etc. Also, for actual implementation, I have tied the 2 HW interrupt lines to the microcontroller and will be using that in future. For the time, I just want to understand how to implement the right code to deliver the desired outcome. Using some test code, I can see data coming from xL, XH, yL, yH, zL, ZH but don't fully realize how to apply it for the desired outcome. The application is very straightforward; to measure forces on the PCB that are primarily in 1 axis. After looking at a handful of code samples (there are few to be found) it's gained some clarity but still not there. Also, I didn't find the app

Posted on December 15, 2014 at 16:09hi all I want to use long periodic reading 3 axises. I configurate the LIS3DH using by reference source code ODR = 100Hz Normal_power mode turn on the x,y and z enable. then now I read 3 items for 1 sec period. It happended Overrun...I read 16th or 14th  it occured the reset... It means all parameter value reset to zero. So I want to use BDU(Block Data Update) or any possible method? what should I do?

Posted on December 13, 2014 at 09:19Hi, In LSM303C there is a tempearture sensor.Whether this sensor measures IC temperature or environment temperature?While reading through I2C it is giving constant value.Temperature value is not varying.Please help me to solve this.Thanks.Regards,Anuhya.   #lsm303c

Posted on December 12, 2014 at 15:51GlobalhealthUSA a Disease management and healthcare analytics company is having a problem finding an ST product we need for a proof of concept demo for ONC. The product of interest is a smart watch described by ST as: Wearable solutions The wearable device market has seen rapid growth in recent years. At TECHNO-FRONTIER 2014, ST will demonstrate its wearable-device platform that places multiple sensors (a motion sensor, a barometric pressure sensor, a temperature and humidity sensor, a proximity sensor, and a MEMS microphone) around an ARM�Cortex�-M-based 32-bit microcontroller, leveraging ST's advanced technologies and expertise in signal processing and data detection.In addition, ST will demonstrate a wristwatch-style optical heart-rate monitor solution for smart watches and fitness devices. This solution uses an ultra-low power 32-bit microcontroller, an a

Posted on November 25, 2014 at 19:01Hello!I have a very specific question about MEMS microphone and noise induced by contamination. Refering to http://www.st.com/st-web-ui/static/active/jp/resource/technical/document/application_note/DM00103202.pdf, it is stated in chapter 2.1.1 that microphones can exhibit a high SNR or high noise output if contaminated. The high SNR I can understand if for example the MEMS membrane get sticky with say soldering flux. But what is the mechanism for just high noise at the output?The background to my question is that I'm developping an acoustic camera using 32 MEMS microphones. I got as far as ordering my first prototype PCB and everything worked fine at first but after while I started to see very high intermittent noise at the o

Posted on December 11, 2014 at 10:37Hi, I am using LSM303C in my project where I need to generate an interrupt for both activity and inactivity. I have enabled INT_XL_INACT bit in CTRL_REG3_A register, but continuously I am receiving the interrupt.And what is the difference between Interrupt generator1 and Interrupt generator2 , what I need to enable in order to trigger activity interrupt.Please help me to sort out this issue as this is in critical priority for me.Thanks.Regards,Anuhya. #lsm303c

Posted on November 25, 2014 at 14:46All: Are there any plans to complete the description for CTRL_REG6? All other control registers have two tables, one high level to show the bits in the register, and a second table to describe in detail the bits. CTRL_REG6 has only one table. I have Doc ID 17530 Rev 1, dated May 2010. #lis3dh #lis3dh

Posted on December 04, 2014 at 13:28Potting resins affect accelerometer behaviour if the Young modulus of the resin is lower than the modulus of the accelerometer packaging.In fact the full system (accelerometer + potting resin) vibrates with the same vibration modes of the ''softer'' material between the two, resin or packaging.This can be measured as an increase of the noise density after applying the potting resin. Specifically the noise density of the LIS3DSH increases of about a factor 2 after applying an epoxy resin with E = 80N/cm2It turns out that E=80N/cm2 is not enough. Instead of going through a number of trials, it would be very usefull to know in advance the Young Modulus of the sensor packaging, to simply select a resin with greater/equal rigidity.This information is not contained in the sensor sheet, where the only info pertaining to the packaging is that it is ''ECOPACK