MEMS and sensors

Posted on June 03, 2015 at 17:02 While working with the LSM303D, I ran into the following problem: The application:To detect disturbances in the local magnetic field (the sensor is stationary). I average a set of readings, and then subtract this offset from the raw magnetic data. I would like to utilize the threshold interrupts on the sensor, so rather than subtract in software, I would prefer to offset the data in the sensor. The problem: I am able to write data to the appropriate X, Y, and Z offset registers, and confirmed via a readback the the data is correct, but the sensor readings are nowhere near zero. If I subtract the same readings in my program, the results are approximately zero. Configuration: i2c_start_wait( (LSM303D_ADDR) + (I2C_WRITE) ); i2c_write(INT_CTRL_M); i2c_write(0xF1); //Enable int recog for x,y,z axes; open drain; active low; no latch; enable generation i2c_stop(); i2c_start_wait( (LSM303D_ADD

Posted on May 21, 2015 at 16:09Hi,I'm using SHT15 to measure temp&humidity. Here,I connected I2C1_SCL  in PB6.I2C1_SDA in PB7.I attached the SHT drivers i created. Unfortunately, I couldn't see the values on serial communication. Could some one look into my code and help me out. 

Posted on May 27, 2015 at 15:54HiI have a weird problem.I manufactured a PCB with to accelerometers on it. One is LIS3DH and the other if from other manufacture (ADXL346).Both works from 1.8v regulator and are connected to on the same I2C bus. Both also connected to a microchip pic micro and works fine. I can read and write to the registers and read X Y Z values.By mistake I connected 12v to the regulator instead of 3.6v and both accelerometers stopped to work.I found that the 1.8v regulator is not good and I replaced it with a new one. I also replaced both accelerometers with new one.My problem is :I can read registers and read X Y Z values from the ADXL346 and it works fine but:I cannot read X Y Z values from the LIS3DH (I get zero at all three axis) but I can read and write to every other register on it. I can rea

Posted on October 23, 2014 at 01:15I was looking for mbed resources for the F401 and VL6180 Board referenced in manual. Is that available? #vl6180x

Posted on July 25, 2014 at 23:28Hello everyone,I am using iNEMO with AHRS algorithm provided by ST. I have noticed that there is a problem about function pointers initialization. These function pointers are used to point the  AHRS algorithm (whose code is not provided by ST). In particular, three instructions are used to execute this algorithm: 1) // Init the all AHRS parameters     iNEMO_AHRS_Init(&xSensorData, &xEulerAngles, &xQuat);2) //update    iNEMO_AHRS_Update(&xSensorData, &xEulerAngles, &xQuat);3) // Deallocate memory    iNEMO_AHRS_DeInit(&xSensorData, &xEulerAngles, &xQuat);These function pointers are pointing to a part of FLASH memory, but RAM reservation is also required to allocate something used by the algorithm. In fact one has to use the following instruct

Posted on May 13, 2015 at 11:48I am using the lis3mdl sensor with msp430 microcontroller sensor, the initial plan was to use SPI interface but it turns out the SDI pin was acting like an output pin instead of receiving data from the micro-controller. Then I switched to i2c but  the sensor when connecting  the vdd io and vdd to the vcc of the micro controller the program was unable to debug and gives power supply error. I believe it is hardware error. Does any one has faced similar problems? Note that all the proper connections were made as shown in the datasheet.My other question is is there any detailed information on how to initialize the lis3mdl via SPI?  because the data provided on the datasheet and application is not very descriptive.The last question is when using the I2c mode should I connect the CS pin to ground? what about the int pin should I connect it to GND if I don�t use the pin?

Posted on May 13, 2015 at 17:27Hi, i need to configure a lis2DH to detect tap and interrupt my micro.i cannot find any application note  about it.Please help me,thanks

Posted on May 09, 2014 at 17:02Hello, I'm working on mic MP34DB01. I want to use this mic with mps430 mcu. It's not clearly on datasheet, the communication protocol is SPI right ? Can the microphone triggered data? thanks #mems-microphone #mems-microphone

Posted on May 13, 2015 at 07:34 Hi, I wish to calculate the tilted information using LIS331DLH accelerometer. I get the code to calculate tilted information when HP filter is not enabled.(I have added in this post) . when filter not enabled , they multiply z axis with 100000 and divide the result by 1024 and calculate the angle. How can I calculate the tilted information when HP filter enabled? /* **If condition is true, then acceleration is along negative x-axis. **Else it is along positive x-axis. */ if(x_axis & 0x0800) { x_axis = ~x_axis; x_axis = x_axis + 1; x_axis = x_axis & 0x0fff; x_direction = -1; } /* **If condition is true, then acceleration is along negative y-axis. **Else it is along positive y-axis. */ if(y_axis & 0x0800) { y_axis = ~y_axis; y_axis = y_axis + 1; y_axis = y_axis & 0x0fff; y_direction = -1; } /* **If condition is true, then acceleration is along negative z-axis. **Else it is along positiv

Posted on February 08, 2015 at 19:05hi,I've been looking for a way to estimate sound intensity using MEMS microphone for a very long time. I am using STM32F4DISCOVERY board with a MEMS microphone on it (it's MP45DT02). I wrote an application that receives sound using this this microphone, writes it into a buffer and converts it from PDM to PCM using library given by ST. So far it works very similar to a program given by ST - ''Audio playback and record''. Later I use fast fourier transform to get the signal spectrum.I need to estimate how the amplitude of the sound will be reflected on the spectrum's bars height. The datasheets are modest or even say nothing about it. How can I solve the problem?  #mp45dt02-mems-microphone-fourier

Posted on May 12, 2015 at 12:02Hi ,we are using LIS331DLH accelerometer for our application.I have some doubts regarding acceleration values. 1) I don't get any horizontal acceleration for below configuration.        Threshold: 500mg.         Interrupt 1 is enabled         INT1_CFG = 0X2A (XH, YH and ZH enabled)2) I get horizontal acceleration when i enable 6D direction movement. But it produce continuous interrupt for small movement with below configuration.         Threshold: 1000mg         Interrupt 1 is enabled         INT1_CFG = 0X6A (XH, YH and ZH enabled

Posted on May 04, 2015 at 13:27I came across your portfolio for MEMS-acceleration-sensors and the H3LIS331DL suits my needs for a new developed pcb-design.I came across the non-linearity column in the data-sheet and wondered whether I understand the information correctly.Does �2% non-linearity� mean that in Full Scale from -70 to 70 [g] (140g total) I could measure a difference of around 2.8g? e.g. The Device measures in between 7.2 and 12.8 [g] by an actual g-Force level of 10g.Thank you for your help! #h3lis331dl

Posted on May 07, 2015 at 04:07I'm a researcher at the University of Sydney using an http://www.adafruit.com/product/1604 to create a prototype measuring instrument. My background is in Civil engineering, so I'm not too versed in electronics. To help evaluate the performance of the instrument, I need to know whether its 3-axis accelerometer (LSM303) is comprised of 3 separate single-axis accelerometers, or if the sensing is done with a single proof mass. It would be great to have a citeable source for this information also. This kind of information is available in this http://www.st.com/web/en/resource/technical/document/technical_article/DM00034730.pdf for gyr

Posted on May 04, 2015 at 23:24Please help to get Orcad Footprint for MP34DT01

Posted on May 02, 2015 at 20:28Seems there is a bug in the Linux installer for the MKI109V2 software package. Calling the 'unico' executable failed persistently with ''no permission'' error, even as root. Setting the 'x' flag for unico (chmod command) fixed the issue - the installer just omitted to make the executable 'executable'. System was a i386 Linux Mint 17 XFCE, which, as a Ubuntu derivative, is assumed to fall in the ''Debain-like OS'' class. #stsw-mki109l-unico-installer-bug

Posted on May 02, 2015 at 13:38Good morning guys. I'm writing because I need help for interfacing an Inemo M1 with a STM32F4. I have the need to take all the sensor values of  Inemo on  F4 via USART. I used to start the sample code of  'Inemo called ''AHRS_LIB_Continuos'' and I implemented a small library for port configuration USART1 that I post below:#include ''inemo_usart_interface.h''#include ''iNemo_Led.h''/* PIN on J12 equal to Tx 6 (GPIOA9) e Rx 7 (GPIOA10)*/FlagStatus xUsartTxComplete;FlagStatus xUsartRxComplete;void usart1_IRQHandler(void);ErrorStatus usart_initialize() {    USART_InitTypeDef usart_init;  NVIC_InitTypeDef NVIC_InitStructure;  GPIO_InitTypeDef GPIO_InitStructure;    /*Enable usart periph clock */&nbs

Posted on May 09, 2014 at 01:19What units are reported in OUT_TEMP_H for the temperature sensor? Is there any increase in power consumption due to enabling the temperature output registers? Is there any factory calibration for the temp sensor? How can I use the temp sensor to determine approximate ambient temperature?

Posted on April 23, 2015 at 22:41 #steval-mki126v3

Posted on April 22, 2015 at 10:19LSM303D�?�指�?�针，�?�现在水平校准�?�，如果器件本身倾斜会对计算出的角度准确度产生较大影�?。如何应用加速度传感器�?�补�?�由于器件�?水平带�?�的误差呢？网上有很多资料，说是用加速度传感器计算出pitch和roll，�?�俯仰角和横滚角，这两个角度与加速度值（Ax,Ay,Az）的函数解�?�?是什么呢？

Posted on April 20, 2015 at 15:10HiIs there a formula for lis3dh turn-on time, taking into account ODR value?Thanks Yaron

Posted on March 07, 2015 at 23:49I have a one of the VL6180x sensors that I have soldered leads onto and configured as specified in the datasheet.Using this library on GitHub I'm able to read ambient light measurements, but range measurements are not working:https://github.com/sparkfun/ToF_Range_Finder-VL6180_LibraryI'm reading a value of 255 for the range measurement and the (0x004D)RESULT_RANGE_STATUS registers bits[7:4] contains a value of 1 which is described in the app notes AN4545 as a system error.After looking over the code from GitHub I'm not too confident in it. I've spent a few hours making changes and applying some of the suggestions here in the forum that I believe are relevant. However, I want to make sure that it is a software issue before I go much furthe

Posted on April 16, 2015 at 15:18Hi everyone. I purchased 109v2 motherboard for my thesis. The board itself didn't recognize 123v1 board (LSM330D) even after numerous trials so I decided to upgrade the firmware via DFuSe software. I obviously used the latest release of the dfu file, which is called ''eMotionV2_REF_4_0.dfu'' acquired from http://www.st.com/web/en/catalog/tools/PF261470 website. (The .zip package also contains Unico, Windows Drivers etc.) I started my device on DFU mode by pressing SW2 button, DfuSe recognized it as ''STM Device in DFU Mode'' everything was normal, dfu file downloaded well. When I tried to Verify, it says ''Matching not good, First difference at adress 0x080045c0''. And it no longer can boot up in normal mode. Also not recognized by Windows. Just in DFU mode if I p

Posted on April 14, 2015 at 15:04Hi in the documentation you wrote that the INEMO-M1 can be addressed as slave by the I2C1 port. How can we do this? I can't found the slave address for the INEMO module in the documentation Is the INEMO firmware already planned to communicate trough the I2C1 port or should i write my own firmware? Thanks #inemo-m1

Posted on April 12, 2015 at 21:12Hi, I have developed, printed and mounted a custom iNemo based board: I noticed a short circuit between Vcc and Gnd with my multimeter, so my question is: there is an hidden problem in my circuit (like a short circuit under the smd capacitor that I have placed between GND an VCC) or maybe there is a low resistance connection inside the iNemo chip? Thanks #inemo #pcb

Posted on April 02, 2015 at 23:15Hello guys, I'm a newbie so forgive me if my question is stupid.I'm trying to get the values that the gyroscope of  i-nemoreturns  and i want to send them through SPI to a STM32F4 ... how can I do?