MEMS and sensors

Posted on March 11, 2016 at 07:21There is a problem with LIS3DSH scale offset. We calibrate our devices for 1000 mG and -1000 mG, using raw data from accelerometer. After 1 month warehouse storage at room temperature, difference between values is still 2000 mG, but values are, for example, 991 mG and 1009 mG. Raw data have offset too. What could be problem?

Posted on September 17, 2015 at 15:47Hope that this is the correct forum section for my question. I have some strange problems with my IME002V1 evaluation kit. When I change some register settings in the Eden application and press write all registers I get the Ok message. When reading back the registers they are all FF, nothing is stored. Pressing write and verify all registers will give an error SET03(191 !=255) on all the devices. Downloaded the latest version of Eden 1.2.16.14255 and flash the firmware with 1.00. Anybody a clue why it's not working.

Posted on March 09, 2016 at 05:26Hi. I have connected an L3G4200D to an ATMEGA328P via SPI.WHO_AM_I gives me 211d, or 0xD3, which is the expected value.The values I use for control registers are:CTRL_REG1: 0b00001111CTRL_REG2: 0x80CTRL_REG3: 0x00CTRL_REG4: 0b10000000, but also tried with 0x00CTRL_REG5: 0x00My SPI parameters are:MSBFIRST, MODE3, CLOCK_DIV8Every time I power up the system, I get constant values coming out of X, Y and Z.These values are random. When I power cycle, they change, but keep constant while power is on.WhoAmI is consistently 211d.Do you have any idea what is going on? I also have a LIS331 accelerometer attached to the same ATMega328P, which is functioning well.I tried desoldering the gyro and desoldering it in place, but got no change in behaviour.

Posted on March 10, 2016 at 00:27Section 5.1 of the datasheet explains how to use the activity/inactivity block. However the register description:8.3 ACT_THS (1Eh)Activity threshold register (r/w). Its value is fixed at 0x00. Inactivity threshold I have a little trouble making any concrete sense of that section. But it somehow indicates that although this register exists it is hardwired to 0? What exactly is going on with ACT_THS and ACT_DUR? Thanks, Jon Pry

Posted on March 08, 2016 at 10:56 Hello ,everyone. Now, I have some prolem about LIS3DSH . I tried run ''state machine'' LIS3DSH presets WakeUp from AN3393 page 78, but anything I do, the interrupt occur on INT1 all the time. What is the Problem ? These codes debug on my device:   LIS3DSH_GetWHO_AM_I(&tmp); printf(''whoamI?.........\r\n''); if(vtmp==0x3F) printf(''IamLIS3DSH(0x%d)\r\n'',tmp); else printf(''Iam???~\r\n''); LIS3DSH_WriteReg(0x21,0x01); LIS3DSH_WriteReg(0x23,0x48); LIS3DSH_WriteReg(0x20,0x67); LIS3DSH_WriteReg(0x57,0x55); LIS3DSH_WriteReg(0x59,0xFC); LIS3DSH_WriteReg(0x5A,0xFC); LIS3DSH_WriteReg(0x40,0x05); LIS3DSH_WriteReg(0x41,0x11); LIS3DSH_WriteReg(0x42,0x00); LIS3DSH_Wri

Posted on March 07, 2016 at 01:04Hey. I understand that this topic is not the place, there was no forum for the addition.Help with data conversion, we need the full formula. For example, at current consumption register REG_CURRENT is 65527, as I understand it is a negative value, but in the calculation goes completely wrong values. #stc3105

Posted on March 03, 2016 at 18:02I am using the LIS2DH12 chip in a small battery powered box in users' vehicles. Whenever a user accelerates the vehicle, I would like to find out if the vehicle is moving forwards, or backwards, or turning, or going down the slope. However, one cannot guarantee how the user will orient this box in the vehicle. It could be upside down, tilted. Finding exact movement (forwards, backwards), is difficult without knowing the orientation of the box.I want to know if by using the 6D/4D orientation feature in the LIS2DH12 chip, if one can find the position of the box. The manual is light on the exact way to use this feature.From various sources that I searched online, it seems like one cannot deduce the exact orientation of the box(upside down, tilted etc.) without having an additional sensor like gyroscope. I wanted to verify from reliable sources if it is indeed not possib

Posted on March 02, 2016 at 18:42Hi, we have to chose a accelerometer/gyro combo for our sleep/motion tracking wearable. We have a big focus on energy consumption since the form factor of our wearable device should be exceptionally small and therefore we cannot put in a big battery. We are unsure if, power-wise, the MPU-6555 is better or the LSM6DSL, if we do 1 Hz sampling of both accelerometer and gyro and the rest of the time put both in the power saving mode. Can anyone estimate how much average power the LSM6DSL needs when doing 1 Hz sampling of accelerometer and gyro? Thank you and best regards, Patrick #accelerometer #imu #lsm6dsl #low-power

Posted on February 19, 2016 at 17:26Greetings. I would like to use the LPS25H/B as a pressure measuring device up to ~15 psi ''differential''. I know that the datasheet lists the functional range from 260 to 1260hPa absolute, how does this translate to ''differential'' measurements? I realize that the differential measurements reported are simulated and that physical access to a reference pressure cannot be used. Regardless, looking at the 24 bit, twos complement, 4096LSB per hPa pressure output, you ''should'' have no electrical issues reporting up to ~2048hPa or about 30 PSI absolute - more than enough range for my purposes. During my tests, I can achieve up to a 8.3psi differential output, but above 8.3psi applied, the reported output no longer changes. What is the limiting factor, what am I missing? Note that at ~15psi, I do not need particularly great accuracy. If the LPS25H/B isn't up to the task, can you recommend a sensor t

Posted on February 25, 2016 at 16:11Hi everyone,I'm new user of ST product and i want to know if i can use inemo-m1 as a slave device to read datas from sensors.Thanks for reading and help.Salim

Posted on February 24, 2016 at 07:01Hi, we need a humidity sensor for IoT home application systems. HTS211 looks very nice as it seems to be I2C readable at any time (whereas other sensors often need a complicated Measure-Pause-Read Intervall timing). Just we definitely would need the possibility to connect several sensors to one I2C line (we use long distance I2C) - e. g. one sensor for internal / room temperature/humidity, and one or two other sensors need to be mounted optionally (the end customer himself can just connects them if he wants), e. g. for some outside temperature measurement point ... . For this is it necessary for us to get the HTS211 with different I2C adresses. Either fix programmed (e. g. different order numbers HTS211-A1, HTS211-A2), or in some form programmable - by pin, or if you are 100% sure about your Flash solution, it could also be programmable. (but we would prefer some fix solution - pr

Posted on February 11, 2016 at 23:52I am looking to increase the absolute accuracy of the LPS22 pressure reading.  It appears OPC can be set using registers 18h and 19h after soldering.  Can this give my an absolute altitude reading (at a small defined temp range) of +-0.1hPa without zero calibrating?  How do I reset the register using One Point Calibration? Can the temperature be One Point Calibrated as well? #lps22hb

Posted on February 19, 2016 at 09:40I'm planning to use a LIS2HH on the same SPI bus as an EEPROM. But in the datasheet it says the LIS3DH CS pin is selecting SPI or I2C.So is it possible to use SPI to the EEPROM when LIS3DH CS pin is high (the LIS3DH would be in I2C mode)? I feel that it will fail if the I2C address gets matched with SPI data.Possible Solution??This LIS2HH chipset has CTRL4 register which can enable/disable the I2C module.So if I pull CS low and write to this CTRL4 to disable the I2C module then will this help avoid I2C working after CS is pulled HIGH? Or I2C is again enabled after CS is pulled HIGH even if CTRL4 I2C module is disabled?Can someone please confirm at earliest?Regards,Shriharsh Datar #lis2hh #issue #chipselect #spi

Posted on February 17, 2016 at 14:36We have a LIS3DH accelerometer that have ended up in a latch-up state. The output data is -205/-1149/-4759 (X/Y/Z in mg). When performing the self test, the absolute difference between the 2 samples are 7/6/3 (X/Y/Z in mg) which is well below the min limit (> 60mg). Is there any way to recover from this? Do I have to make the accelerometer powerless? #latch-up

Posted on February 09, 2016 at 06:34Hi, I have been using the STEVAL-MKI161V1 evaluation board fitted with a LSM6DS0 module. I am able to replicate the angle calculation used in the UNICO software provided along with the kit using this http://robotics.stackexchange.com/questions/4677/how-to-estimate-yaw-angle-from-tri-axis-accelerometer-and-gyroscope and a complementary filter approach mentioned http://www.pieter-jan.com/node/11. However these are following issues that were unaddressed in the software provided, and my questions are (i) The angle being measured in this method(used in UNICO) always gives angle in the rang

Posted on December 17, 2015 at 22:37I have a LSM9DS0 that I am trying to get operational. My I2C is working since I can read the correct values for both WHO_AM_I registers. I can also read back a control register and the data read matches what was written. The Gyro readings are not stable and don't look correct. I am operating in fifo bypass mode. I've disabled two of the axes via the control register and those axes continue to update and move around. I would think that there would not be any updates to a disabled axis. I am oring the function register with a 0x80 for a multibyte read and I believe that the I2C is working. Should the disable axes be moving on me? Are there any configuration items that can cause this kind of behavior? Thanks, John #i2c-lsm9ds0

Posted on February 03, 2016 at 10:44Hello, my project involves capturing the data from a MEMS microphone array. I found one article which describes, that it is possible to achieve this with a STM32F4 processors, so I would use STM32F407 discovery board. I added the diagram in the attachment. It shows, that the input clock (12.288MHz) is divided and outputed to the MEMS microphone array and also to trigger the DMA. As I understand, the clock passed to the array should be N times smaller than the one passed to DMA, where N is the microphone count. But is it possible to output two different clock from one timer. And if not would it work if I used to timers which were clocked from the same source (for example APB2) and outputed the to MEMS array and DMA respectively? Would the DMA work in sync with the array? #mems-microphone-array #stm32f4

Posted on June 05, 2014 at 22:45Hi All,Having trouble writing a program that will let me operate the iNEMO M1 (STEVAL-MKI121V1) outside of the iNEMO suite provided by ST. I'm running Windows 8x64. Haven't even been able to get the sensor to connect. These message boards have limited information about other models, but does anyone have some working C/C++/MATLAB code to help get me started using the iNEMO M1 SDK, as opposed to the iNEMO SDK that some of the other models use. Thank you! #inemo-mki121v1

Posted on September 16, 2014 at 16:47I have temperature cycled a LIS3DH. I can see that the zero g reading changes every time I cycle the temperature. Is this normal?Have ST made some measurements during temp cycling that I could read?

Posted on January 08, 2016 at 15:57Hi, I am trying to communicate with an LSM6DS0 module via SPI. I can retrieve the WHO_AM_I register content succesfully, but then, when I try to set the CTRL_REG6_XL register to start the accellerometer then I am not able to do it properly. In particular, I write 0x20 and then read it again to doublechek, but the module replies 0xF0. And this happens whatever possible value I try to write into it: it always replies 0xF0. Clearly, when I further try to read the acc. register, no values are present.It sounds like I am missing something. Any suggestion?Thank you in advance and regards.

Posted on January 11, 2016 at 17:07Hello, if am using VL6180x sensor with Arduino Uno board. There are few libraries available on the internet to control this sensor using Arduino boards. The program in the library is written to give sampling rate of 10Hz. The convergence time is set as 30ms for Ranging application ad 50ms for ALS. in all it takes around half a second to give one reading. I require sampling rate of at least 100Hz, a reading to be given after 10ms. I am clueless how to get that much speed, and exactly which parameters must be controlled for that ...... One more question is - what is convergence time?

Posted on December 11, 2015 at 11:38Hi, i don't find the output data rate in the datasheet of the VL6180x proximity sensor. I read only 10Hz in relationship with the current consumption.What are the ODR settable ? ThanksS.Bertuletti #vl6180x #odr

Posted on January 18, 2016 at 18:37Hello everyone, I have a STM32F4-Discovery board with an integrated MP45DT02 MEMS mic, and I've bought also anothere mic (an MP34DT01), I would like to record at the same time from the 2 mics. I'm able to record in RAM and playback the audio from the integrated mic, to do so, I've edited the example application ''Audio_playback_and_record'' (http://www.st.com/st-web-ui/static/active/en/resource/technical/document/application_note/DM00040802.pdf). To decode the pdm bitstream I use the libPDMFilter distributed with the example (its header is ''pdm_filter.h'')... The problem is that the only documentation I've found for that lib is this: http://www.st.com/st-web-ui/static/active/en/resource/technical/docum

Posted on December 05, 2014 at 00:07We are testing out the LSM303D in our new product and we are finding that it is a lo noisier than the LSM303DLHC.    Should this be the case? We assumed that the LSM303D would have less noise.Our init sequence;    writeMagReg( LSM303D_CTRL0, 0x00);    writeMagReg( LSM303D_CTRL1, 0x5F);     writeMagReg( LSM303D_CTRL2, 0x18);     writeMagReg( LSM303D_CTRL3, 0x00);     writeMagReg( LSM303D_CTRL4, 0x00);      writeMagReg( LSM303D_CTRL5, 0xF0);      writeMagReg( LSM303D_CTRL6, 0x60);      writeMagReg( LSM303D_CTRL7, 0x00); #lsm303dlhc #noise #lsm303d

Posted on January 13, 2016 at 19:51helloi use in stm32f4 with Keil uVision5 and STM32CubeMX(i cunfig spi with cubemx ).i want to send and receive data from accelerometerI can not find the SPI function that send/receive data because i search fanctions that Suitable working with cubemxIs it possible to attach the function and code sampleThank you,pini