MEMS (sensors)

Posted on September 23, 2017 at 05:45I am using LIS3MDL sensor and I do not understand the sensitivity which its unit is LSB/Gauss.  In x-cube-mems1 library, the following is calculated:&sharpdefine LIS3MDL_MAG_SENSITIVITY_FOR_FS_4G    0.14 /**< Sensitivity value for 4 gauss full scale [mgauss/LSB] */&sharpdefine LIS3MDL_MAG_SENSITIVITY_FOR_FS_8G    0.29 /**< Sensitivity value for 8 gauss full scale [mgauss/LSB] */&sharpdefine LIS3MDL_MAG_SENSITIVITY_FOR_FS_12G    0.43 /**< Sensitivity value for 12 gauss full scale [mgauss/LSB] */&sharpdefine LIS3MDL_MAG_SENSITIVITY_FOR_FS_16G    0.58 /**< Sensitivity value for 16 gauss full scale [mgauss/LSB] */and in the datasheet:My question is how did they calculate the sensitivity in the above code? and also what does LSB/Gauss mean?Thanks in advance. #lsb/gauss #lis3mdl

Posted on September 24, 2017 at 09:45We have a problem when use full fifo flag and when interrupt happend and we read FIFO flag FTH clears and process start again. When set interrupt on threshold of the FIFO and it happens when read that part of FIFO but flag FTH doesnt clean so interrant never happend again only that once. Chip is LSM6DS3H. Thank you.

Posted on September 15, 2017 at 10:26Hi all,I connected STEVAL-MKI137V1 (Magnometer sensor) to STM32L152D-EVAL through I2C. The library I am using is from STM32CubeExpansion_MEMS1_V4.0.0.I connected I2C pins to PB11 and PB10 without any external resistors on STEVAL-MKI137V1 side.The problem is weird for me. Most of the times the code do not work, it give error like Acknowledge Failure, and sometimes the code works very well without any error!What is the expected reason of this problem? How can I solve it?Note: is the problem related to external pull-up resistors? Because I did not use them.Thanks in advance.#steval-mki137v1 #i2c

Posted on September 21, 2017 at 23:49Hi all,today I started a new project using the LIS2DH accelerometer (I2C mode). Previously I already used, very successfully, LIS3DH, always in I2C mode. Seeing the datasheets, in the basic functionatity, LIS2DH and LIS3DH are pratically the same object (the LIS3DH has just 3 extra ADC channels...): same registers, same setup and, theorically, same I2C Address, (0x18 when SA0 = 0, 0x19 when SA0 = 1). So, I was expect an easy porting of my code because, I repeat, theorically, LIS2DH and LIS3DH, are the same device. Theorically!I don't know why, but using 0x18 (my SA0 is 0) the LIS2DH do not comunicates. I was going crazy: I do three times a rework of the pcb (I was thinking that maybe the problem was the board): nothing, nothing and nothing.So I had this idea: I checked all I2C's space address, from 0x00 to 0x7F. I got no response, as previously, at 0x18 but, incredible, I got a response at 0x29.Mmmm...very strange but...Ok, I updated my .c library

Posted on September 21, 2017 at 11:59I'm using MP34DT01 MIC ,but i found that the niose is extremely large.My mcu is STM32F429VGT6,using its I2S peripheral.I use  libPDMFilter_IAR library convert  PDM signal to PCM signal.but there is a large amount of white noise.A group of sample data is in the attachment.(PDM data read from the mic in quiet environment)Is these sample data correct?Can you give me some advise? if you know Chinese--我最近使ç�?¨ä¸€é¢—STçš„MEMS MIC芯片，型å�·æ˜¯MP34DT01，但是测试å�‘现有é�žå¸¸å¤§çš„白噪声.我ç�?¨çš„MCU是STM32F429，通过I2S读å�–MICçš„PDMä¿¡å�·å¹¶ä¸�?ç�?¨stm32f407discovery附带的一个例程里é�¢çš„软件库转æˆ�PCMä¿¡å�·è¾“出。附件是抓的一组在安é�™çŽ¯å¢ƒä¸‹MIC输出的PDMæ•°æ�®ï¼Œè¿™äº›æ•°æ�®çœ‹èµ·æ�¥æ­£å¸¸å�—？Jasper

Posted on September 14, 2017 at 14:24I have recently bought a STM32 Dev board with a X-NUCLEO_IKS012A mems sensor. I am new to embedded software and decided to get one of the example projects going for this board. I have gone through all the readme's etc. but st doesn't specify where to save the example project when downloaded from the internet. I get the following error:make: *** No rule to make target `C:/Users/Charl Smalberger/Src/com.c', needed by `Example/User/com.o'. Stop.Looks like a path related error.I am using system workbench. I have attached the readme with basic instructions that i followed, the workbench instructions are at the bottom.Please can anyone assist?#isk01a2

Posted on April 26, 2017 at 11:02Hello, I am using VL6180X-SATEL on STM42F4 Discovey Board and download the STSW-IMG003 software. When I implement it in Keil v5.0.0 and try to use vl6180x_simple_ranging.c code, program shows mi 3 errors, that file vl6180x_sample_plat.h in vl6180x_simple_ranging.c cannot be found, and that unist.h and pthread.h cannot be found in vl6180x_platform.hI was looking all over the downloaded files, but found nothing. Wonder if you can help me with this problem, and describe where i can find solution?#pthread.h #vl6180x_sample_plat.h #unistd.h #vl6180x

Posted on July 07, 2016 at 13:26I've encountered a problem with LPS25HB. I'm trying to get maximum precision from this barometer sensor without taking into account power consumption. I've setted up registers in this way and in this order: CTRL_REG1 0x20 => 0b11000110; // Power on, 25Hz, BDU, reset zero RES_CONF 0x10 => 0b00001111; // AVG-P 512, AVG-T 64 After reading documentation I've tried to enable also FIFO in mean mode to get a more precise reading, in this way and in this order: FIFO_CTRL 0x2E => 0b11000011; // FIFO Mean mode, 4 moving average CTRL_REG2 0x21 => 0b01000000; // FIFO Enable  Conversion that I do from readings are: Pressure = ReadedPressure /  4096UL; Temperature = 42.5 + (ReadedTemperature / 480UL); Reading are ok if I just initialize CTRL_REG1 and RES_CONF, correct temperature and reasonable pressure readings. But if I try to activate FIFO_CTRL and CTRL_REG2 (in this order, first FIFO_CTRL and after CTRL_REG2 registers), with above bit

Posted on September 13, 2017 at 11:50Hi,I am looking for the FIT data and test conditions for part number LPS25HB. I could not find the information available on the website.

Posted on September 12, 2017 at 12:16Hi, everyone,I am quite a newbie in MEMS sensors!Just got a sensor Tile at hand, having fun with this device and the app.I am wondering if someone uses 3D accelerometers like LIS3DH to measure the respiration rate(or breath rate)?If I lay down with sensor on my chest, usually I have few hundreds of mg, like below: (using LSM6DSM on the sensor Tile board)(I just noticed that the above x axis is sample counts, not time. Sorry about that!)So it seems possible to use accelerometer ic to measure respiration rate!Or is there any other MEMS sensor can be used to get respiration rate?Thanks for reading this post! .Zt#sensortile #accelerometer #respiration #breath

Posted on August 26, 2017 at 11:40I am reading data through I2C. The calculations performed are correct (Converting high and low bytes into a 12 bit value and using 195mg/digit to convert data into scales of +/- 400g level.).There is a noise of about +/-10g in all the three axis. So the graph will always be fluctuating when the device is kept still.Neglecting the +/- 10g noise, the X and Y axis data are fine. But Z axis data is always shifted by about 8g. So the Z axis data has an average of 8g, when the device is upright and kept still, which had to be 1g. So the graph of Z axis will be fluctuating at 8g with.

Posted on September 04, 2017 at 11:29Hello, I'm currently working with an LSM9DS1 and want to read the gyroscope/accelerometer data via FIFO. I enabled the FIFO in CTRL_REG9 and set FIFO mode in FIFO_CTRL. Everything else regarding the FIFO is set on default. I read the data by accessing the X/Y/Z output registers. (This might be unrelated but at the moment I'm initializing the registers in order of the data sheet. Therefore I set the gyro before the accelerometer registers. I initialize the gyroscope with an ODR of 59.5 Hz and later the accelerometer with 50 Hz which doesn't seem logical. But I want do set the g scale of the accelerometer in CTRL_REG6_XL and by that automatically set the ODR.)The problem now is that the read data is not written in the FIFO storage. (When I check the FIFO_SRC register the number of samples in the storage stays 0) Two interesting things happen: - if I keep all the settings as they are and only change CTRL_RE

Posted on June 12, 2017 at 12:28Hi,I'm investigating the use of the LSM6DSL in a future project (to replace our use of the LSM6DS3) and I have been testing the STEVAL-MKI178V1 evaluation part.There appears to be some strange signal on the Z axis of the accelerometer (that was not present on the older LSM6DS3), have I just received a faulty part?I've attached pictures of 30s of measurement data from the 6 axes (gyro_x, gyro_y, gyro_z, accel_x, accel_y, accel_z) with the sensor in 3 different orientations. The strength of the rogue signal always seems to be constant (around 100 LSB, or 6 mg at our scale).The sensor is configured to be in high performance mode, 104 Hz output data rate, +-2g full scale.Thanks,Nick#lsm6dsl #accelerometer

Posted on September 09, 2017 at 07:28Hello all,I am using STM8S003K3 for my appplication with STVD IDE and Cosmic compiler and using Touch Library for my application.I have added touch library in project and configure it as to work with STM8S003K3.I have my own designed hardware as below. -- Soldered STM8S003K3 in PCB. -- connected Vcap. -- 1M reg. from LOADREF. pin to each Touch pin. -- 10 k reg. in between controller pin and solder mask. -- Touch pad is designed with single layer bare PCB masked in round shapes(where i have soldered wire from 10k reg.) for individual key and on opposite side there is a paper marked with no.s.I am using TIM2 as a TIMAQ and TIM4 as generic timer.I have configured PE5 pin as a LOADREF. pin and rest as touch pin.After succcessfully build when i debug and check if any of key pressed, i am unable to get any of key pressed.There is no voltage on LOADREF. pin.I have atttached configuration file and main file.Can any one guide me please, where there is a pro

Posted on September 06, 2017 at 06:49I was trying to Build a project for the 'sensortile - STEVAL-STLKT01V1' using 'System Workbench for STM32' and I get this error message 'Invalid project path: Include path not found (C:\STSW-STLKT01_V1.3.1\Projects\SensorTile\Applications\DataLog\SW4STM32\STM32L47xx_SensorTile\Debug\Inc)'.#stm32l476jgy6 #sensortile

Posted on September 02, 2017 at 22:41Hello:I have been fighting with this accelerometer for a couple of months and it has now become imperative that I get it functioning.I am using it with an STM32F405 controller. I have it set up in interrupt mode. When I get an interrupt, I read and process the X,Y,Z registers but the values are always (or almost nearly)  the same: -20, -3, -6.I have absolutely not a clue what is going on. Can anyone please help me with this? Here is the code to process the data after the interrupt. Directly below is the call to SPI read that the handler usesuint8_t SPI_read(uint8_t address){  GPIO_SetPinLow(GPIOD, ACCHI_CS);   address = 0x80 | address;   // 0b10 - reading and clearing status    while(SPI_I2S_GetFlagStatus(SPI3, SPI_I2S_FLAG_TXE) == RESET);   SPI_I2S_SendData(SPI3, address);  while(SPI_I2S_GetFlagStatus(SPI3, SPI_I2S_FLAG_RXNE) == RESET);  SPI_I2S_ReceiveData(SPI3);   while(SPI_I2S_GetFlagS

Posted on September 05, 2017 at 00:08The datasheet shows that setting the D4D_EN bit to 0 enables 4D orientation detection, however in AN5040 in section 5.4.2 it states the opposite.  Also at the end of section 5.4.1 it shows steps to enable 6D detection, including setting TAP_THS_6D to 0x40 (leaving the D4D_EN bit low).  Which of these is correct, app note or datasheet?  I would be inclined to trust the datasheet over the app note, except using 0 to enable the bit as shown in the datasheet sounds like it might be wrong.

Posted on July 21, 2017 at 16:06The DRDY flag in the STATUS_A register does not seem to work. I am running the acellerometer at ODR =  100Hz, FIFO bypass mode, HR mode. Every time the STATUS_A register is read it outputs the value 65, the DRDY is the least significant bit and it is always set. It looks like the flag is never reset.If I syncronize the magnetometer with the acellerometer running both at 100Hz and reading the acellerometer data after the magnetometer data (after DRDY pin set from magnetometer) it looks like I get reasonable acelleration data (new data each time).Is there any trick to make the DRDY bit and STATUS_A register work as it should? On the LSM303AGR I did not get high resolution data when using the fifo. I guess there is another snag here on the LSM303AH where I probably have to use the fifo or do something else, I cannot see any detalis about this in the data sheet/manual.

Posted on June 12, 2017 at 12:08Hello, I would like to use the LIS3MDL magnetometer in single measurement mode to reduce my overall current consumption.I've found some useful informations in the AN4602 Application but I'm still missing something.The turn on time, from wakeup command to data availability, is specified (as a function of the operating mode) but the current consumption during turn on is not given.What value should I use for my calculations?ThanksGuillaume#power #lis3mdl

Posted on January 12, 2016 at 13:15How may i know about self-test, what is the procedure after enable self-test for each one, and what kind of data will there that i have to use for further analysis, and how. #self-test

Posted on August 30, 2017 at 19:09I am trying to test the magnetometer on LSM9DS1 sensors.Can I apply the same self-test range-values than the LIS3MDL compass to check the LSM9DS1? The fact is that the magnetometer in the LSM9DS1 seems to be a LIS3MDL (same documentation of the registers). I am using the http://www.st.com/resource/en/application_note/dm00136626.pdf, where the self-test procedure is explained in page 19, with self-test ranges indicated in table 17.I already implemented a self-test procedure for the LSM9DS1 and I obtained for one sensor on which I suspect a problem the following values:Average_X_self_test - Average_X_no_self_test = 2551 (no scale) = 0,93 gaussAverage_Y_self_test - Average_Y_no_self_test = 2682 (no scale) = 0,98 gaussAverage_Z_self_test - Average_Z_no_self_test = -415 (no scale) = -0,15 gaussAnd for a second sensor that seems ok, the values are:Average_X_self_test - Average_X_no_self_test = -4476 (no scale) = -1,64 gaussAverage_Y_self_test - Average_Y_no

Posted on July 31, 2017 at 12:56Hello, I want to do a self test to lsm9ds1.Is there any file that explain how to do it?I found some sources  but nothing official.If there is not official file, i have some questions:Is the sensor can't be in motion at the time of the self test?Is the sensor must be in specific position?How to make self test to the magnetometer?Thank youYair Sarid#self-test #lsm9ds1

Posted on July 07, 2017 at 02:25Dear sir/madam,I'm confused how the Threshold decodeing(degrees) comes like shown in LIS2DS12 datasheet, page 31. When 6 stands for 80 degrees and how 6 comes from?I try to use 60 degrees threshold and I can read accurate each axis value now, but how can I compare 60 degrees with accurate output values for xyz axis?Thank you very much.

Posted on September 03, 2017 at 10:27Hello sir,HELLO EVERYBODY,I have a question about LIS3MDL.   Expecially, interrupt problem.I am using LIS3MDL below sequence.=================================================================================1. In normal circumstance, I get a basic data for reference threshold of Interrupt.Normally, 0.4 ~0.5 gauss.   And plus 0.1 gause for offset value.2. I put in the data for Threshold value. And I enable the interrupt. 3. Wait the interrupt (basic data[0.4 ~0.5 gauss] + offset[0.1 gauss])4. If interrupt is happened, the interrupt signal wake main CPU(stm32f103rct6)problemI checked how many times interrupt is happened, in normal circumstance(0.4 ~0.5gauss)In our office, interrupt is not happened.   ( It is good because our office does not have the change of geomagnetic)Outside, interrupt is happend eventhough there are nothing to change geomagnetic.==>I wonder why the interrupt is happened outside?  &n

Posted on July 13, 2017 at 14:06I did not quite understand from the pdf when reading 32*3 samples from the FIFO in SPI mode, can I set the SPI starting address at OUT_X_L (28h) with the SPI's MS bit raised and then read in a constant SPI read stream (single message) all of the 192 bytes?Or do I need to read the SPI starting with  address (28h | 40h) in 32 different messages?I saw in a previous post, that you can use the FIFO only in 10bit mode.Is this true?#lis2dh-fifo-spi