MEMS and sensors

Posted on June 24, 2016 at 11:23Hi all, I have some questions regarding the LSM9DS1: 1. The Acceleration ODR choices go down to 10 Hz, however the bandwidth selection, presumable an anti-aliasing filter, is limited to 50Hz. Thus, when sampling at 10Hz or 50Hz with a bandwidth selection of 50Hz severe aliasing is to be expected. Is there a way to avoid this? 2. The accelerometed digital filter operation is not documented properly. What dow ''high resolution'' refer to? How is LPF or HPF selected? 3. Is there a block diagram for the acceleration signal available, similar to Figure 28 in the datasheet for the gyro signals?

Posted on December 09, 2012 at 14:41Hello, I'm trying to get the MEMS Accelerometer on my STM32F4 Discovery Board to run with a simple code, but I don't make it. Heres my code: int main(void) {         SystemInit();         GPIO_InitTypeDef GPIO_InitStructure;         SPI_InitTypeDef  SPI_InitStructure;         RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD | RCC_AHB1Periph_GPIOA | RCC_AHB1Periph_GPIOE , ENABLE);         RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);           //Init SPI-Pins           GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;

Posted on December 23, 2015 at 02:58Hi, I would like to use the osxMotionFX for the STM32L053 Nucleo board I have. Any plan for a release? It seems to be working only on Nucleo F401RE. Also when I install the osxMotion Setup V1.4.0, I get an error message during the license wizard installation ''floating point 0''. Anyone had the same issue? Thanks, Pierre

Posted on November 01, 2015 at 15:25Hello,this is my first time that i use gyroscope on stm.so please, can you answer this simple question:what are the libraries that i should add to the project to use gyroscope?thank you for answering

Posted on August 12, 2015 at 22:51Hello I'm trying to use the L3G4200D Gyroscope to measure the pitch in 3 dimention.But I faced a problem with: I used the Keil's examples.Iuse SPI to read and write on the device...I can read some registers such as WHO_AM _I  etc. I also used these control register configuration: Gyroscope_Write(CTRL_REG1, 0x0F);     /* ODR: 100Hz, Cut-Off: 12.5,         */ Gyroscope_Write(CTRL_REG4, 0x00);     /* Continuous update,full scale 250dps*/ Gyroscope_Write(CTRL_REG5, 0x40);     /* FIFO Enable                        */ But I can't read state registers(X, Y, Z).My problem is that the result read from the gyroscope is not stable at all where it is

Posted on November 26, 2015 at 10:49Hello,I'm integrating an L3GD20 gyro into a device, to replace a different gyro.  For X, Y and Z, everything is fine, but the temperature is not.If you look at the attached jpeg picture, this is a graph from when the device was tested in the test oven.  The red and blue lines are the temperature readings of the old gyro (red line) and the secondary CPU (a 8051 based RF controller, blue line).  Both of these lines more or less track what the oven was doing during the test.  The L3GD20 seems to be running backwards.  However, on the datasheet it reads ''Temperature data (1LSB/deg - 8-bit resolution). The value is expressed as two'scomplement.''  I did some searching for this on the internet, and found a couple of Arduino sites which discussed similar behavior, but with no solution.The reading is being done by SPI done by an FPGA. &n

Posted on February 11, 2016 at 17:24Hi, I've tried to upgrade the firmware via DfuSe Demo, but it hungAfter this, I've discovered that my STEVAL-MKI109V1 board has bricked.I can flash it again using a Nucleo Board's embedded STLink. I could test it and I've read the memory contents, so I am very confident about being able to write a binary on it.Is there someone who could send me a binary image for this board?PS: I've tried to extract .hex images from .dfu files inside ''stsw-mki109w.zip'', but all of them are bigger than 64kB (the size of STM32F102R8T6 that is on MKI109V1 board)

Posted on March 23, 2016 at 09:22Hello, I am working with STM32F429 Discovery evaluation board. I have interfaced LSM6DS3 with evaluation board over I2C. LSM6DS3 provides good functionality of reading steps counts from it directly without putting more effort on Microcontroller side. Currently I am trying to measure Stairs count using LSM6DS3. Please try to address my below queries. 1) Is there any library available to calculate stairs count for STM32F429 and LSM6DS3? 2) If library is not available then please provide some references regarding how to count stairs count from LSM6DS3. It would be more appreciable if any kind of suggestions will be got. Thanks, Bhavin

Posted on July 03, 2016 at 07:07What is the maximum voltage of the L3G4200D INT1 pin (assuming open drain)? What does the PP_OD bit in CTRL_REG3 control - INT1 only or INT1 and DRDY/INT2? What are the maximum voltages applied to all I/O pins? Why are ST's datasheets SO BAD?  This part has been in production for 6 years.  There's no excuse for not documenting it. #l3g4200d

Posted on July 03, 2016 at 14:04 Sample program to get accelerometer data. #include ''stm32f3xx.h'' // Device header void initSystem() { // LSM303DLHC wiring: SCL to PB6, SDA to PB7. // Enable port B timing and set pins to alternate function mode. No pull-up/pull-down. RCC->AHBENR |= RCC_AHBENR_GPIOBEN; GPIOB->MODER |= GPIO_MODER_MODER6_1|GPIO_MODER_MODER7_1; GPIOB->OTYPER |= GPIO_OTYPER_OT_6|GPIO_OTYPER_OT_7; GPIOB->PUPDR &= ~(GPIO_PUPDR_PUPDR6 | GPIO_PUPDR_PUPDR7 ); GPIOB->OSPEEDR |= GPIO_OSPEEDER_OSPEEDR6 |GPIO_OSPEEDER_OSPEEDR7; // Select AF4 (0100=0x4) to toggle I2C_SCL function on pin PB6 and I2C_SDA on pin PB7. GPIOB->AFR[0] |= (0x4 << GPIO_AFRL_AFRL6_Pos); GPIOB->AFR[0] |= (0x4 << GPIO_AFRL_AFRL7_Pos); // Enable I2C peripheral clock. RCC->APB1ENR |= RCC_APB1ENR_I2C1EN; // Set up TIMINGR (CubeMX). I2C1->TIMINGR = 0x00501E26; // Peripheral Enable. I2C1->CR1 |= I2C_CR1_PE; }

Posted on July 11, 2016 at 22:52Hi all, I've recently bought a couple of LSM9DS0's for a simple project. Before soldering them to my board I tried to checked if everything was right. I ONLY connected pin 5 and 6 to GND and 15, 16 and 17 to 3v3. However when I turned on the power supply, it showed up a short circuit. I was wondering if anyone has an idea on what is wrong. I don't think that I burnt them by static as I used them with a wrist band connected to GND. Besides, the cut-off current on the power supply is set to 200mA. I'm also attaching the design of the board I was planning to use with the IMU if anyone has an opinion about it. Best regards

Posted on May 04, 2016 at 16:07Hi to all, i have this shield x-nucleo-6180XA1 with mi STM32L152RE, i setting PB8 and PB9 for I2C1, i want to test the shild i want to see the who i am,  i write this easy code   &sharpdefine IDENTIFICATION__MODEL_ID  0x000   //who I am &sharpdefine PROXW  0x52 &sharpdefine PROXR  0x53 &sharpdefine DEFUALT_ADDR 0X29 void I2C_WHOAMI(I2C_HandleTypeDef *hi2c1, __IO uint8_t whoami){         while((hi2c1->Instance->SR2&BUSY)==BUSY);   //  Start     hi2c1->Instance->CR1 |= START;   while((hi2c1->Instance->SR1&SB)!=SB);   dummy16 = hi2c1->Instance->SR1;     hi2c1->Instance->DR = PROXW;   while((hi2c1->Instance->SR1&ADD

Posted on June 21, 2016 at 18:19The datasheet doesn't specify how to convert register (OUT_TEMP_L (0Ch), OUT_TEMP_H (0Dh) ) data to actual temperature. let's say for example if reg 0x0c = 0x7 value and reg 0x0d = 0x00 value, then what will be the temperature. #lis2dh #temperature #temperature-sensor

Posted on January 25, 2016 at 12:25Hi,I am trying to use multiple VL6180X sensors and attach them to a robotic arm. Is there the possibility of interference between them? If the answer is yes, is there any way to avoid it?ThanksMarina #multiple-vl6180x

Posted on July 10, 2016 at 20:53Hi I would like to get the signal strength very much.So, please let me ask two questions.The first one is about a function in vl6180x_api.c.julien@ST said like following in the Discussion Board named ''How to measure the ToF'':>No, there is no way to access to the time of flight. Only distance, signal strength, ambiance rate ...>Signal strength is the amount of the photons coming back from the target.>You can access to this field ''rtnRate'' in the struct ''VL6180x_RangeData_t'' below.So, I saw the _GetRateResult function in the vl6180x_api.c.However, I couldn't understand clearly following part:>        calcConvTime = m_refConvTime;>        if (m_rtnConvTime > m_refConvTime) {>            calcConvTime = m_rtnConvT

Posted on July 07, 2016 at 18:19 Hi, I faced with the problem of acceleration calculations on lsm303dlhc I read registers and past them, but in x, y, z variables contain crazy values, if demoboard is on the table, values must be x: 0, y: 0, z: 1000, but i get x: -1499 y : -1499 z:49 Range +-2g. Please, describe process of calculating acceleration in m/s^2 if i have values from registers int8_t buffer[6]; uint8_t aTxBuffer[8]; int16_t pnRawData[3]; while (1) { HAL_I2C_Mem_Read(&hi2c1, 0x32, 0x28 , 1, (uint8_t*)&aTxBuffer[0], 1, 1); HAL_I2C_Mem_Read(&hi2c1, 0x32, 0x29 , 1, (uint8_t*)&aTxBuffer[1], 1, 1); HAL_I2C_Mem_Read(&hi2c1, 0x32, 0x2A , 1, (uint8_t*)&aTxBuffer[2], 1, 1); HAL_I2C_Mem_Read(&hi2c1, 0x32, 0x2B , 1, (uint8_t*)&aTxBuffer[3], 1, 1); HAL_I2C_Mem_Read(&hi2c1, 0x32, 0x2C , 1, (uint8_t*)&aTxBuffer[4], 1, 1); HAL_I2C_Mem_Read(&hi2c1, 0x32, 0x2D , 1, (uint8_t*)&aTxBuffer[5], 1,

Posted on July 03, 2016 at 06:57 What is the maximum allowable voltage applied to the INT pins (assuming open drain)? Why are ST's datasheets usually incomplete? #h3lis200dl

Posted on July 07, 2016 at 11:19Hi everyone,I have tried to communicate with LPS22HB by I2C, and then I realized that the defaut value of CTRL_REG2 is 0x0, but the defaut value indicated in the datasheet is 0x00010000. Is there anyone has the same problem??Thank you,Dung. #lps22hb

Posted on July 04, 2016 at 08:11Dear ST engineer,I use LIS3DSH for digital angle meter development.But I have calibration error on LIS3DSH.I am study ST DT0053 6-point tumble sensor calibration.Could you give me a calculation example for the sensor calibration?The following information is read form LIS3DSH:[1g,  0g,  0g] = [17322, 1197, 217][-1g, 0g,  0g] = [-15315, 467, 300][0g,  1g,  0g] = [1362, 17266, 288][0g, -1g,  0g] = [719, -15656, 212][0g,  0g,  1g] = [1009, 894, 16636][0g,  0g, -1g] = [1177, 759, -15883]Thanks.Edison

Posted on June 16, 2016 at 13:24Hi,the self test procedure described in AN4602 starts automatically by setting bit 0 to '1' in CTRL_REG1 register, but it is not well explained how to check if the self test passes or fails.If the self test passes, the device performs the calibration by itself? #lis3mdl #selftest #lis3mdl #self-test #lis3mdl-temperature-calibration #calibration

Posted on June 23, 2016 at 23:53I have read over the user manual for the MEMs board, and I am using the example code from the DataLogFusion. However, I can never get the osx_MotionFX_compass_isCalibrated function to return true. I have tried hitting the reset button, moving the board clockwise in all three axis, moving it in a figure 8 and lots of different combinations. Anyone have an idea how to do this successfully or what may be the problem? Thanks!

Posted on January 28, 2016 at 13:10Dear All,I am using LSM330DLC gyro-acc on my board and I have forgotten place pull-up resistors on the SPI/I2C selection pins. However it works fine. My question is can I develop my project without these pull-up resistors?It is mentioned, in datasheet, these pins must be high for I2C operation, but in my case it is 0V and I2C works well.

Posted on June 06, 2016 at 03:14I'm using IIS2DH, I config it to normal mode, so It's 10bit resolution, and I got 16bit data for each axis, now I right shift the 16bit data to get a 10bit data, and the range is 0-1023, is that right? but And if I keep the board horizontal, I got the Z = 125*7.81mg/digit= 1g, it's right, but if I reverse the board, the ideal Z should be -g, right? But I got the data which is 905, so Z = 905*7.81mg/digit = 7g, it's not right, I can't find  details about how to convert data to g in the website, who can help me ? #data-convert #g #iis2dh

Posted on May 25, 2016 at 14:09Hello guys, I'm planing to use LIS3DHTR accelerometer in my next project. There is one thing (for the moment :-)) that is bothering me: The default state of the INT1 and INT2 pins is not explicitly indicated within a datasheet (at least I could not find it). I'm curious to know what is default state of the INT1/INT2 pins and what is the state of those pins when the interrupt occurs? Is this parameter (the state during the interrupt) configurable through I2C/SPI interface or there is just one default value? Thanks in advance for your time and effort. Sincerely, Bojan. #lis3dh #lis3dh-interrupt

Posted on May 25, 2016 at 18:57Hello everyone. This is my first posting on this forum. I am an electrical engineering major completing a senior design project. I am designing a smartwatch and I purchased the STEVAL MKI159V1 motion sensor and this will be my first time working with the Raspberry PI 3 microcomputer and my first time working with a motion sensor. My question is where can I find instructions on how to connect the STEVAL MKI159V1 that contains the LSM9DS1 to the Raspberry PI 3 via the I2C connection on the Raspberry PI 3.? This was not taught in my EE education and I want to make sure it is connected correctly. I plan on measuring the motion sensor data and eventually filtering out any noise. Thank you for any input you can give me. #mems