MEMS and sensors

Posted on July 25, 2017 at 20:35LIS3MDL doc says take 16 bit signed Temperature Register values, divide by 8, and add 25 degrees C.   I get a value that is always about 11.5 degrees  warmer than what the ASM330LXH on the same board is reporting, and the ASM330LXH appears to be pretty close to actual room temperature.    Is it really a 25 degree offset? or should it be 12.5 degree offset?  value 0x0057 = 87;  87/8 = 10.875;  10.875 + 25 = 35.875 degrees C = 96.575 degrees F.  It just isn't that hot in here, and the two sensors are physically very close to each other.Is this temperature measurement only useful for relative temperatures?

Posted on July 23, 2017 at 16:54Hi all ,    I used BlueNRG-MS found a problem , the MCU is freescale chip and used SPI communcation with BlueNRG-MS , but the MCU send the configuration information to BlueNRG-MS , start I could read 0x04 0xFF 0x03 0x01 0x00 0x01, and then write configuration information , but each only read 0x04 0x10 0x01 0x00 . is not the correct data .This image is first read the data , and comparison of normal board data is correct .This is every send configuration information , and read data , is always this data , but normal is not is data .    Please tell me why is read this information ?  why reason could read this information ? How to modified my code could read the normal data . Thanks for your attention .

Posted on June 13, 2017 at 14:08I am working with IIS2DH accelorometer an I would like to configure single/double click tap detection. For that, I have done following configuration:I2C_WriteByte(&ctrl_1,1,0x5F);  I2C_WriteByte(&ctrl_3,1,0x80); I2C_WriteByte(&ctrl_6,1,0x82); I2C_WriteByte(&ctrl_4,1,0x00); I2C_WriteByte(&int1_config,1,0x00);  I2C_WriteByte(&ctrl_5,1,0x40); I2C_WriteByte(&click_config,1,0x15);I read click source register for single click detection but values are different every time. Also,interrupt flag not set for microcontoller.Is there any thing need to be wrong in my configuration?Is any application note for IIS2DH(DM00171283)?

Posted on July 17, 2017 at 08:22hello, I have gone through the datasheet and app note of LIS3MDL. But i am not able to get how block data update bit work i.e. if someone has set the BDU bit and if I read registers through I2C one by one, then how the ic internally gets idea that all the registers have been read and got the data of same sample?Also can anyone please elaborate about ODR and its working in LIS3MDL

Posted on July 19, 2017 at 14:30I have done following configuration to detect double click. I am able to detect double tap but it is consider four times.I2C_WriteByte(&ctrl_1,1,0x5F); I2C_WriteByte(&ctrl_3,1,0x80); I2C_WriteByte(&ctrl_6,1,0x82); I2C_WriteByte(&ctrl_4,1,0x20); I2C_WriteByte(&int1_config,1,0x00); I2C_WriteByte(&ctrl_5,1,0x40); I2C_WriteByte(&click_config,1,0x2A); I2C_WriteByte(&time_limit,1,0x05); I2C_WriteByte(&click_ths,1,0x30); I2C_WriteByte(&time_latency,1,0x05); I2C_WriteByte(&TIME_WINDOW,1,0x80);while(1) { click = I2C_ReadByte(&click_src,1);    if((click & (1<<6)))    {       print('click detection');   }}Is anything wrong with my configuration? How I can overcome to get multiple times to print 'click detection'? Double tap detect only on hardware but if I want detect around the hardware hoe can I get it?

Posted on July 18, 2017 at 10:45Hi, I am working with LIS2DE12 accelerometer, I want detect any new data is updated  to temperature and x,y,z axis registers.can any one provide steps for configuration. 

Posted on July 17, 2017 at 16:25Hello,I try to read acceleration values from a LIS3DSHTR using the STM32F091 �C. I use SPI with DMA to read the values but I have trouble with the incoming datas in the RxBuffer.On my two screenshots you can see the bus communication and the position of the data inside my RxBuffer. The order is totally wrong.I hope someone can check the source code. I hope you can find a stupid mistake void SPI_init(){    SPI_InitTypeDef SPI_InitStructure;    // clk    RCC->AHBENR |= RCC_AHBENR_GPIOAEN;    RCC->APB2ENR |= RCC_APB2ENR_SPI1EN;    // set af mode    GPIOA->MODER = ( GPIOA->MODER & ~(GPIO_MODER_MODER5 | GPIO_MODER_MODER6 | GPIO_MODER_MODER7));    GPIOA->MODER |= ( GPIO_MODER_MODER5_1 | GPIO_MODER_MODER6_1 | GPIO_MODER_MODER7_1);    GPIOA->AFR[1] = (GPIOA->AFR[1] &~ (GPIO_AFRL_AFR5)) | (0 << GPIO_AFR_POS5);

Posted on March 29, 2017 at 12:47Hello STM!I am facing a new goal: I want to build my own diferencial beamforming 2 MEMS PDM microphone array to achieve kardioid directivity pattern.So i need to get data out of two MEMS mics simultaneously ... i mean literally get samples at the same time (because the beamforming depend havily on time that sound travel through space, so i will try not to add any delay between the two mics samples). So i am thinking what approach for data aquisition here is the best.I got two variants at the top of my head. I will mention i am going to use probably some of STM32F4 168 MHz or higher (reason is that i developed so far a lot of my app using single microphone at this mcu and it had suitable performance for all the signal processing needed)    1. Variant:Aquire both PDM via one I2S data line using the 'trick' with double PDM clk frequency from I2S routed to a timer (to divide the clk by 2) so i can aquire both of mems mics with

Posted on July 14, 2017 at 07:24The magnetometer on my device has different scale and offset on its axes.This is because of influence of hard iron on the board. So, it needs to be calibrated. I've read https://my.st.com/resource/en/design_tip/dm00286302.pdf and hadn't understood about rotated ellipsoid. Rotated about what? I made calculations according this manual with matlab. Offsets and gains are adequate, but rotation matrix is strange. When I fit the data with offsets and gains, the angles (yaw, pitch, roll) I computed are normal. When I fit with offsets, rotation matrix and gains, the angles are strange. The second question. When I fit the data with normal calibration values all vectors have magnitude 1. How to convert it back to gauss?The crosses are the original data, the rounds are transformed data.Transformation ''offset-rotate-scale'' is on the left side.Transformation ''offset-scale'' is on the right side.#magnetometer

Posted on July 13, 2017 at 23:03I just downloaded the new STM32CubeFunctionPack_MOTENV1_V3.0.0 and going through what motion sensor library could do all at once.As I walk through the code in MEMSCallback(), all the W2ST_CHECK_HW_FEATURE checking is using 'if' and not 'else if'..... So is that meant all features can be detected all at once ?For instance, can W2ST_HWF_FREE_FALL and W2ST_HWF_PEDOMETER  be enabled at the same time ?? and get correct status ?Most specific to page 20 on 'en.FP-SNS-MOTENV1_quick_start_guide', it shows all individual Motion features.However, Mobile Apps would only able to show status one at a time.  Does, features actually running in parallel at firmware background ?Any doc list out how Application was implemented ?

Posted on July 09, 2017 at 11:47Hello sir,I meet a problem that I can present 6D positions now except (a) and (c) [both are related to left side] situations shown in LIS2DS12 application note. I can not find the problem. I output the 'position' exact data instead, for these two wrong situations, it is always shown 0, which should be shown 2 and 4 as expected. I'm thinking wether the x-axis is broken. Or are there any other reasons to cause this problem? (the 4th value after Get Acceleration shown the input interrupt value)WHO_AM_I_REG 0x43Get Acceleration: 38 897 -378 0Get Acceleration: 37 897 -378 0Get Acceleration: 39 900 -374 0Get Acceleration: 38 899 -377 0Get Acceleration: 110 937 -402 0Get Acceleration: 38 900 -373 0position change********** success 6D event function^_^ position = DW_RS  8Get Acceleration: -1884 611 -850 0position change********** success 6D event function^_^ position = unknown 0Get Acceleration: 799 438 349 0Get Acceleration: 986 -12 251 0Get Acceleration:

Posted on July 11, 2017 at 12:48Hi,I am trying to test my I2C connection with my STM32nucleoF411RE but I can't seems to have any response from my MKI142V1. I have tested the start condition and sending the address but it doesn't seem to retrieve the acknowledge bit that the sensor should send back. So my question is, can I really test the MKI142V1 without MKI109V2 that everyone recommends ?

Posted on July 09, 2017 at 14:40I posted in another forum but a fellow user suggested I post here.https://community.st.com/thread/41907-why-does-my-linear-sensor-array-not-scalenormalize?sr=inbox&ru=17270null

Posted on June 01, 2017 at 15:39I've got my LIS2DH12 configured as follows:TEMP_CFG_REGTEMP_EN0x11CTRL_REG1ODR1LPEN0ZEN1YEN1XEN1CTRL_REG2HPM0HPCF0FDS0HPCLICK0HP_IA10HP_IA20CTRL_REG3I1_CLICK0I1_IA10I1_IA20I1_ZYXDA0I1_WTM1I1_OVERRUN0CTRL_REG4BDU1BLE0FS0HR1ST0CTRL_REG5BOOT0FIFO_EN1LIR_INT10D4D_INT10LIR_INT20D4D_INT20CTRL_REG6I2_CLICK0I2_IA10I2_IA20I2_BOOT0I2_ACT0INT_POLARITY1REFERENCEREF0FIFO_CTRL_REGFM1TR0FTH1INT1_CFGAOI16D0ZHIE0ZLIE0YHIE0YLIE0XHIE0XLIE0INT1_THSTHS1INT1_DURATIOND0INT2_CFGAOI16D0ZHIE0ZLIE0YHIE0YLIE0XHIE0XLIE0INT2_THSTHS0INT2_DURATIOND0CLICK_CFGZD0ZS0YD0YS0XD0XS0CLICK_THSLIR_CLICK0THS0TIME_LIMITTLI0TIME_LATENCYTLA0TIME_WINDOWTW0ACT_DURACTD0After configuration, the registers look like this:whoAmI 33tor 1tda 1sdoPuDisc 0tempEn 1odr 1lpen 0zEn 1yEn 1xEn 1hpm 0hpcf 0fds 0hpclick 0hpIa1 0hpIa2 0i1Click 0iaIa1 0iaIa2 0i1Zyxda 0i1wtm 1i1Overrun 0bdu 1ble 0fs 0hr 1st 0sim 0boot 0fifoEn 1lirInt1 0d4dInt1 0lirInt2 0d4dInt2 0i2Click 0i2Ia1 0i2Ia2 0i2Boot 0i2Act 0intPolarity 1referen

Posted on July 05, 2017 at 14:43STEVAL-MKI155V2 coupon board,cannot find exact pin number.On silk on the board, and no layout file on st site.And on en.DM0006727d.pdf, bottom view image seems to be mirrored.Please let me know where  I can  find the MKI155V2 pin map.

Posted on June 29, 2017 at 16:53Hi,I'm using X-NUCLEO-IKS01A1 with arduino uno,I'm getting the output for HTS221 with the codehttps://github.com/ControlEverythingCommunity/HTS221/blob/master/C/HTS221.c  ,the connections seem to be correct but when I'm trying to get the output for LPS25HB from the code https://github.com/ControlEverythingCommunity/LPS25HB/blob/master/Arduino/LPS25HB.ino I'm always getting the output as 0 hpa only.Even when I'm applying the pressure at the sensor.In the datasheet it is there that CS should be connected to VddIO ,I think it is internally connected as all the sensors in  X-NUCLEO-IKS01A1 are in I2C line.Please do needful.I need LPS25HB working with arduino UNO.Thanks and Regards,Radhika

Posted on July 04, 2017 at 15:39Hi,I'm using X-NUCLEO-IKS01A1 board for integrating the pressure sensor in my Atmel board SAM G55 series.I'm using the reference code of https://github.com/ControlEverythingCommunity/LPS25HB/blob/master/C/LPS25HB.c .I can able to get the correct output from WHO AM I register but the problem is that when I'm reading the output registers 0x28,0x29,0x2A ,the values are showing always as zero and they are not changing.Even If sometimes ,the registers are showing some value,the values are not changing even when the pressure is applied.I have configured the control registers too. 0x20 as 0x90 and 0x21 as 0x01.Can you please let me know any clue on why the output registers are not changing and always showing as zero.Please help me.Thanks and Regards,Radhika

Posted on June 05, 2017 at 11:40I am trying to measure a machine's vibration using LIS3DH sensor. I set the LIS3DH in low power mode and 5.376 kHz sampling frequency which outputs 8 bit output. I use spi to get the data from the sensor. I changed this raw output into �g' using the sensitivity value given in the datasheet.My problem is: The sensor shows a fluctuation in its output of Z axis even when there is no vibration applied and the sensor is fitted on a horizontal surface. The range of this fluctuation is approximately from 0.6g to 1.2g. I have attached a image that shows such output. (X axis is time and Y axis is vibration in terms of g)Can someone please help me to interpret why this is happening ? Is there a method to somehow remove this noise from the output ?Please help.#lis3dh-spi #lis3dh #mems-accelerometer

Posted on July 02, 2017 at 14:49Hi everyone, we are working the the LSM6DS0 from ST interfacing through SPI with a CC2650 microcontroller. We have been able to test our custom PCB, read some data from the accelerometer, but we are not able to configure the interrupt generation (neither from OUTPUT data available neither from threshold high event detected)We have a couple of doubts, since there are no resources online about the PCB electrical connection. Should the interrupt pin be connected directly to the input GPIO of the uC? Should we use some pull up, pull down?Here we report the dump of all the registers we read on our debugger together with a synthetic description of all our configurations.ALL REGS DUMP (obtained through SPI, after some time): [0] '\x00'[1] '\x00'[2] '\x00'[3] '\x00'[4] '\x00'[5] '\x00'[6] '\6a'[7] '\x32'[8] '\x32'[9] '\x32'[10] '\xfd'[11] '\x00'[12] '\x41'[13] '\x00'[14] '\x00'[15] '\x68'[16] '\x00'[17] '\x00'[18] '\x00'[19] '\x00'[20] '\x00'[21] '\x3e'[22] '\x

Posted on June 30, 2017 at 19:28Hey guys I have been working with VL53L0X and Stm32F7  at my company so the problem is that it can identify the chip ID well but get a ERROR_CONTROL_INTERFACE at the first api callVL53L0X_DataInit(&MyDevice);After further debugging HAL_I2C_Master_Receive gives an timeout error but HAL_I2C_MASTER_TRANSMIT goes through fine.The device address for read is set to 0x53 while for write is 0x52 

Posted on June 22, 2017 at 18:21Hi,I have X-NUCLEO-IKS01A1 having 4 MEM sensors ,I have seen that this board is compatible with arduino UNO,I have connected the board same as like the ST nucleio board,but I couldn't find the sensors giving output with arduino UNO code . I have also connected the board with Intel edison,but I couldn't detect the addresses of the sensors.Can you please let me know the hardware connection of X-NUCLEO-IKS01A1 with arduino UNO .I'm providing 5V as input (Vin) and added pullup resisters too.Thanks and Regards,Radhika

Posted on June 28, 2017 at 12:38Hi, I'm having some problem using the LSM9DS1 FIFO...My objective is to continuously acquire, without loosing samples, the Gyro and Accelleration data. (The magnetometer is turned off)This is what I do:- I set the watermark threshold to 21 samples (IMU_FIFO_samples = 21 (IMU_FIFO_samples = FlashBuffer_Initialize(IMU_6);)- I configure the interrupt to be sent to pin INT1_A/G (LSM9DS1_configInt(XG_INT1, INT_FTH, INT_ACTIVE_HIGH, INT_PUSH_PULL);)- I configure the FIFO in Bypass Mode (LSM9DS1_setFIFO(FIFO_OFF, IMU_FIFO_samples);)-- In order to start the data acquisition I configure the FIFO in Continous Mode (LSM9DS1_setFIFO(FIFO_CONT, IMU_FIFO_samples);)(I did try to set the IMU_SAMPLE_RATE to 14Hz and 900+Hz but the results are the same)void IMU_Initialize(void){ uint16_t tst; IMU_FIFO_samples = FlashBuffer_Initialize(IMU_6); LSM9DS1_LSM9DS1(IMU_MODE_SPI, XGADDR, MADDR); settings.accel.sampleRate = IMU_SAMPLE_RATE; settings.gyro.sampleRat

Posted on May 19, 2016 at 04:45 Hi guys, I new to STM32, was mostly use PIC32 for USB audio application but due to cost decided to switch to STM Now I have STM32F0 discovery board with STM32F072RBT6. I tried to setup USB audio with CubeMX and compile with out no issue. Now I would like to change the Audio Sampling rate to 48KHz instead of 1KHz (code default value). Once change to 48KHz, the code will run into Hard Fault exception. So I take a look into the code and sort of does not understand below part (summarize from various .h and .c) #define USBD_malloc (uint32_t *)USBD_static_malloc #define USBD_AUDIO_FREQ 22100 #define AUDIO_OUT_PACKET (uint32_t)(((USBD_AUDIO_FREQ * 2 * 2) /1000)) //=4=88bytes /* Number of sub-packets in the audio transfer buffer. You can modify this value but always make sure that it is an even number and higher than 3 */ #define AUDIO_OUT_PACKET_NUM 80 /* Total size of the audio transfer buffer = 88*80=7040 bytes!*/ #define AUDIO_TOTAL_BUF

Posted on June 23, 2017 at 15:24Hello,I am interfacing SPI based LSM6DS3 accelerometer to imx7 based board. I got LSM6DS3 driver from  'https://github.com/STMicroelectronics/STMems_Linux_Input_drivers '. Added device tree for this (kernel-4.1.15) as below.        lsm6ds3@0{                compatible = 'st,lsm6ds3';                reg = <0>;                spi-cpha;                spi-cpol;                spi-max-frequency = <50000>;                interrupt-parent = <&gpio2>; &

Posted on June 22, 2017 at 14:51We have two prototype boards each equipped with a LIS331HH.One of the sensors seems completely broken because the Z axis shows values around 2.3g while laying flat on the table. Because of that we were now looking into self tests to check all sensors in production.We query all the axis and divide each value by 16. The data sheet tells us that 1digit is 3mg so we expect 333 on the Z axis and 0 on X and Y. We measure X:20, Y: 35 and Z: 373, which is an offset we expect [1].Now we start the self test in plus mode and measure X: 177, Y: 131 and Z: 828.The self test values differ by X: 157, Y: 96 and Z: 455 from the non self test values.In the data sheet there are values for 'self-test output change'. Those mean, that X and Y are supposed to differ by a max of 180 and that Z may only differ by 370?So this sensor passes the test on X and Y and fails on Z and therefore we have to throw this sensor away, right? Or did we misunderstand the process and