MEMS (sensors)

Posted on April 18, 2017 at 07:48I'm using an LIS3DH accelerometer. It is configuring properly and returning valid data when manually read at a fixed interval. Now I'm trying to switch to the use of its XYZDA signal that is emitted on INT1.I have all other interrupts on INT1 disabled, and I'm enabling XYZDA by setting bit 4 of CTRL_REG3. If I clear the bit, INT1 stays inactive, and if I set the bit, INT1 starts showing activity, so I'm confident I'm setting the bit I think I am {grin}.A scope shows that INT1 goes active at ODR intervals, as expected. The problem is INT1 resetting to inactive. Section 3.1.2 of the LIS3DH's app note says 'the interrupt is reset when the higher part of the data of all the enabled channels has been read (29h, 2Bh, 2Dh)'. This seems clear enough... read the MSB of all three axes and INT1 should be cleared.However, what happens instead is that INT1 clears at variable times, often many tens of milliseconds

Posted on April 13, 2017 at 01:08With a 2g scale sampling @25Hz the FIFO fills with data and I am reading the contents up to the watermark. HR and LPen are disabled.With the Z-Axis pointing toward earth I get the following data for the X-Axis using the H and L bytes:DATX=128DATX=128DATX=128DATX=-64DATX=192DATX=-128DATX=-64DATX=0...First, why are the values multiples of 32? Second, why the variability when the chip is still and not moving? I have been using the LIS3DSH for a couple years now so this IIS2DH is a real downgrade for sure, but I must be missing something. I have read over the manual several times now and can't find my issue. -AP

Posted on April 13, 2017 at 12:58The detailed behaviour of the LSM303DLHC DRDY pin (pin 9) is not elaborated upon in the datasheet.We have observed that it generates active low pulse but this is not detailed in the datasheet. What are the timing requirements on responding to DRDY?At which point during this low pulse are the registers ready to be read?Should the DRDY bit in register SR_REG_M be read to verify that a new set of measurements is ready, or is just using the DRDY pin sufficient?

Posted on April 12, 2017 at 17:13I am moving to the IIS2DH from the LIS3DSH because it is end of life. I am having an issue with reading the FIFO. I can enable FIFO mode and it seems to fill and generate an interrupt on OVRN and WTM just fine, but the X, Y and Z high and low registers are all value 0x80. And reading the data does not empty the FIFO. Can you suggest what would cause this? Otherwise it seems very similar the LIS3DSH which I have no issues with. -AP

Posted on April 11, 2017 at 08:08 We are upgrading our IMU from a LSM9DS0 to LSM9DS1. However we are having issues with the magnetometer on the LSM9DS1. Even after min/max calibration it doesn't appear to give correct heading. We are aware that the orientation has changed and have taking this into consideration. When using this simple formula, i would expect some usable results (this works perfectly witht he LSM9DS0)... however this is not what we are seeing. heading = 180 * math.atan2(MAGy,MAGx)/M_PI To rule out our PCB design, we have purchased products which use LSM9DS1 from Adafruit and Sparkfun, and these also have the same issue. Below is the code used to initiate the magnetometer # CTRL_REG1_M (Default value: 0b0001 0000) # [TEMP_COMP][OM1][OM0][DO2][DO1][DO0][0][ST] # TEMP_COMP - Temperature compensation # OM[1:0] - X & Y axes op mode selection # 00:low-power, 01:medium performance # 10: high perf

Posted on April 11, 2017 at 12:31Hi, I have designed a circuit which has 8 LIS3mdl sensor slot on 1 spi bus.The problem when I connect only one ls3mdl sensor (other 7 are empty) to the board it works well. but most of the when I connect another one ( sometimes 2 and sometimes 3 or 4 and more) all sensor stop working. ( it reads the register values but the wrong parameter get back) in this mode, I am reading sensors one by one.(make one of SS(chip select) 0 talk to sensor and make it 1 and then do the same with next sensor). Immediately when I reduce the number of sensors to 1 it works correctly and when and more sensor it goes wrong.I myself think that the problem appears because when SS pin for other sensors is high and it means they are in i2c mode and they talk in I2C on the bus and it makes conflicting(i saw wrong data coming in debug mode and in oscilloscope) I once though the

Posted on April 10, 2017 at 21:38Does LIS2DH support 12-bit high resolution mode with FIFO?

Posted on March 30, 2017 at 21:02Hello,     We are working with the LIS2DHTR and have had significant yield issues after running the board through the reflow oven.  For the next run we plan to lower the temperature.  But for now we are replacing the units by hand are are still having issues.     Has anyone ever dealt with MEMs failures after reflow or rework.  I have also noticed that units behave differently following rework.  For instance, we are setting a threshold in software to generate an interrupt from the accelerometer.  In different units, the force required to generate the interrupt can be significantly different.      Are there any tips on assembly for these parts?ThanksCraig

Posted on March 21, 2017 at 15:35I'm using the LSD6DSL in an application where the sampling rate (ODR for the MEMs) is important. The ODR in the datasheet is only given as 'Typical'. Could I get a more precise specification for the ODR, e.g. min/max values over the entire temperature range. I suppose this ODR is generated from an internal oscillator with tolerance, temperature drift, ...

Posted on March 29, 2017 at 08:37Hi, I'm new with stm32 and mbed environment. I'm trying to use VL53L0X satellites as proximity/distance sensor but I have few unsolved questions: 1) in this datasheet I can see that only first six pin of satellites are used: <LINK NO LONGER ACTIVE> is right? 2) is there an easy example on how to use it like this for hcsr04 arduino sensor: <LINK NO LONGER ACTIVE> ?? (examples given by downloading his own software are little bit difficult based to my knowledge)3) which pins i have to connect if I don't want putting this board on the stm32 board?Thanks for the support

Posted on April 03, 2017 at 12:56Apple watch accelerometer axis range Hi good morning,I'm developing an apple watch health care application. After a search i discover an ST microelectronics accelerometer sensor mounted on a system on a chip internally.Here there is the sensor data sheet: http://www.st.com/content/ccc/resource/technical/document/datasheet/a3/f5/4f/ae/8e/44/41/d7/DM00133076.pdf/files/DM00133�I want to know one only thing: Which is the full scale range ? I read the data sheet but i've found 4 differents range for range on axys (2G, 4G, 8G, 16G)!I'm not very expert with data sheet reading, someone can help me ?Thanks in advance, have a good lunch!#applewatchaccelerometer #fullscalerang

Posted on April 07, 2017 at 08:14I'm using the LIS3DH set at 1 Hz ODR.  My SPI hardware seems to be working since DATA_RDY interrupts come in fine at a steady 1 second interval and the accelerometer data looks good.  In fact I get good data at all speeds.  However I can't seem to get the threshold interrupts working.  I read the app notes, found setups on the web, and tried a lot of different configurations.  Below is a sample setup.Could you send me a register sequence that you know works to trigger an INT1 interrupt?Also the ADC seems to give me 2032 to -2032 for a range of .9 to 1.8 volts maybe this is a clue.  The temperature gives me -16 so I haven't been able to get this working either.  Self test seems ok.ThanksJeffrey Wedekind #define LIS3DH_CONFIG_CTRL_REG1 0x17 // 1 Hz, Zen, Yen, Xen #define LIS3DH_CONFIG_CTRL_REG2 0x00 // Default Settings #define

Posted on April 06, 2017 at 21:58Couple of questions regarding the LSM6DSL (iNEMO intertial module) setup via the SPI interface.1. Should it possible to program the IMU at 10 MHz SPI interface or does the programming need to be done a slower speed?2. Is there a delay required when doing Read followed by a Write or vice versa? It appears that a small delay of 4-5 us is required after a read and before a write otherwise the write doesn't go through as intended.Thanks for your pointers and suggestions.

Posted on April 05, 2017 at 00:02Although powering an LSM9DS1 with 2.8V to VDDIO and VDD, I would like to use a 1.8V-logic line for one of the chip selects for ease of retrofitting an existing design with minimum upheaval.  The line is push-pull, not open collector.The sufficient-voltage threshold for a '1' digital input is usually labeled V_IH, but I could not find that parameter listed in the published specifications.  What is V_IH for the LSM9DS1 digital inputs, especially the chip selects?A corollary question -- even if 1.8V will be sufficient fully to deselect the chip-select, would using 1.8 instead of 2.8V lead to increased power consumption?Thanks!#lsm9ds1

Posted on September 02, 2016 at 18:04We are developing a product using the VL53L0X IR Time-Of-Flight sensor. The sensor must be inside a plastic case looking through a IR transmissible window material. To test such an arrangement the X-NUCLEO-53L0A1 comes with airgap spacers and cover glass materials. I would like to know what this cover glass material is, can you give a manufacturer name, article/product name or something? #vl53l0x-x-nucleo-53l0a1

Posted on April 06, 2017 at 08:15for Doing FMEDA I need FIT rate value for IC LIS3DHTRIn data sheet ,reliability data  it is not mentioned.

Posted on April 05, 2017 at 11:44I have an LSM6DS3 gyro / accelerometer connected to a Raspberry Pi 3B using i�c. I'm using the internal FIFO to get samples from the gyro and accelerometer. The data is plausible most of the time, however, every now and then there is a strange sequence of values when I read the FIFO:sample output:47    -240    -371    143    -238    -378    ...138    -240    -369    141    -238    -361    ...137    -238    -381    134    -247    -373    ...130    -229    -367    133    -235    -370    ...134    -236 &nbs

Posted on December 13, 2016 at 20:28I have an issue with a batch of LSM6DS3 and I would like to check the chip mark code. I was able to convert the barcode into a code (785320G709QQ) but I couldn't find a place to identify what each number means. The datasheet doesn't mention anything about the barcode/markcode. I just don't know where can I find this information.#lsm6ds3

Posted on March 31, 2017 at 22:44i have an error with STEVAL-MKI109V with STEVAL-MKI175V1 and i am new user.Please help about that.Thank`s

Posted on April 03, 2017 at 15:47Hi ST Experts,Currently i am working on lsm9ds1 sensor. We are done with hardware connection and we have tested it using sample application using ioctl. In this we are using the polling mechanism. We have to get data from sensor ~100Hz and send it to cloud. Now,We want to test it with interrupt driven mechanism. I found that there is a driver available from ST and i have integrated it to our kernel. But somehow its not working for me as expected. I can see data only single time, when i do driver insmod.https://github.com/STMicroelectronics/STMems_Linux_Input_drivers I have couple of questions:- 1) I can not see any interrupts coming on INT1_A/G.?     lsm9ds1-ag@0x6b {    c

Posted on April 03, 2017 at 14:25i generated the keys with the OSXLicence wizzard and generated a mail to transmit information ('between lines') and with the nucleo f401re but i did n't received acknowledgement mail.Can you check this , i'll use it with the wesu as a second sensor 

Posted on April 02, 2017 at 17:07Hi, i worked hardly on the wesu and my windows environment (windows 10 ans windows mobile/phone) and i arrive now to read data from the bluetooth service of the wesu sensor.please find my twitter link to see this.i'm cheking now how to add the assimp library to my project (sharpdx and uwp sdk source code).but now i ned to order 15 wesu to cover entirely the arm/and and add gesture reconizing.if you want offer me again some wesu sample it could permit to share result and progress in the project to add automatic speaking recognizing hand/arl movment for deaf-mute.but a video is always better ... (the video is not very clea but the next video will include hand movment.)https://twitter.com/ChOnillon/status/847161665892290561 

Posted on April 02, 2017 at 12:47Hi All,I am using STEVAL -IDB007V1 development KIT, i installed BlueNRG GI c2.2.2, when i try to connect to the device(click connect), i am getting 2 messages:1-  old usb serial fw detected.2- OLD DTM FW fw detected.How can i update the 2 FW above? Thanks.#bluenrg-1 #steval-idb007v1 #dtm

Posted on March 23, 2017 at 13:25I'm having some troubles using the VL53L0X sensor (53L0-SATEL-I1 board); I used the other satellite board included in the x-nucleo-53L0A1 without any problems, but the 53L0-SATEL-I1 isn't working properly; it seems that the I2C bus is not available when i try to communicate with other sensors in the same bus. Using an oscilloscope i see that the voltage level in the sda and scl pin is about 1.5 Volts instead of 2.8V that should be thanks to the regulator and the level shifter. The input voltage of the 53L0-SATEL-I1 is about 3.3 Volts and in the output of the regulator i see 2.8 Volt correctly. The problem is in the SDA and SCL pin; the voltage is lower than the value should be. Could you please help me? Thanks. Davide #sensor #i2c

Posted on March 29, 2017 at 18:10Hello,How could I enable the DEN_A/G signal?I succeeded to enable the DRDY_M or INT1_A/G signal but I have nothing on this DEN_A/G.Do you have any suggestion?Best regardsMich