MEMS (sensors)

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

Posted on January 05, 2016 at 19:50halloi 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

Posted on January 12, 2016 at 11:12    Hello!I want to ask that is there any type of ST sensor to measure pressure in the water? I want to use the tiny sensor to measure the intracranial pressure.

Posted on January 11, 2016 at 11:04 Hi everybody, I have a custom board hosting anLSM6DS0 sensor and an STM32F427 micro which communicate via SPI. The SPI interface is configured as follow: SPI5h.Instance = SPI_MEMS; SPI5h.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_16; /* 5 MHz */ SPI5h.Init.Direction = SPI_DIRECTION_2LINES; SPI5h.Init.CLKPhase = SPI_PHASE_2EDGE; SPI5h.Init.CLKPolarity = SPI_POLARITY_HIGH; SPI5h.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE; SPI5h.Init.CRCPolynomial = 7; SPI5h.Init.DataSize = SPI_DATASIZE_8BIT; SPI5h.Init.FirstBit = SPI_FIRSTBIT_MSB; SPI5h.Init.NSS = SPI_NSS_HARD_OUTPUT; SPI5h.Init.TIMode = SPI_TIMODE_DISABLE; SPI5h.Init.Mode = SPI_MODE_MASTER; At startup I firstly check if the module is present reading successfully the WHO_AM_I register, then I try to configure theCTRL_REG6_XL register to enable the accelerometer. So I perform the following write/read operations

Posted on January 10, 2016 at 15:18Hello ST Community,I would like to share with you the exiting announcement of the imminent start of the open source project AdaPilot, a safety critical autopilot for unmanned systems (drones) based on the Ada-SPARK language and STM32 MCUs.I would welcome to everyone to visit the website (work still in progress) adapilot.likeabird.eu and in case of interest to contribute in this project.The sensors in the AHRS of AdaPilot uses also ST products.Cheers,-Jarno

Posted on January 06, 2016 at 07:42I'm using LIS3DH_driver project from ST to read axes values from LIS3DH accelerometer. I'm not using STM32 but I have implemented my own LIS3DH_ReadReg() and LIS3DH_WriteReg() functions somehow and they are working without a problem since I can write and read back registers correctly. But the problem is when I call LIS3DH_GetAccAxesRaw() function to retrieve axes values and print them out I don't see a correct value and they are not changing when I hit the accelerometer by thumb and they're really high values even when the board (or the IC) is not moving at all (when I'm not clicking). I have enabled FIFO mode and data rate is 50HZ and WHO_AM_I is 0x33 which is correct I believe. I have not configured any interrupt pins cause I don't need it's functionality. I couldn't figure this out by myself. Anybody have an idea? 

Posted on December 31, 2014 at 08:09 Hello all, I'm having trouble using the AIS328DQ accelerometers. Having the board level I should get roughly 0,0,1 for the x,y,z axis. Every second or third reading is completely incorrect. Often it's zero, sometimes it's much higher than it should be (often up to 2g). This affects all axis. I'm using I2C to communicate. Here is an example of the output -0.01 0.01 -0.02 -0.01 0.01 1.01 -0.03 0.00 1.01 -0.02 0.00 1.00 -0.01 -0.01 1.01 -0.03 0.01 -0.01 -0.01 0.01 -0.02 -0.01 0.00 0.95 -0.02 0.01 1.00 -0.01 0.00 1.07 -0.01 0.00 -0.01 -0.00 0.01 1.01 -0.02 0.01 1.00 -0.01 0.00 1.00 I have checked the I2C bus with a scope and that looks normal. The processor is correctly interpreting the data, it's just that the data is often wrong. The accelerometer is in normal power mode at 1000hz ODR with all axis enabled. The scale is set to +/- 4g. The accelerometer is being read at a 10hz rate, b

Posted on December 30, 2014 at 10:31helloI'am trying to develop an application for voice synthesis using STM32 F4 discovery .for this work i used the project Audio_playback_and_record .however,when i modified the PCM code of const uint_16 AUDIO_SAMPE