MEMS (sensors)

Posted on June 15, 2018 at 07:59Dear Community,In a multi-sensor application, we need to be able to use a fixed sampling rate, which can not be set in the LIS3DSH settings (200Hz, 400Hz, 800Hz, 1600Hz), e.g. 1kHz. My idea was now to use the highest available sampling rate of 1600Hz and start the sensor over SPI for a single conversion, then stop the sensor and start it again after 1ms (for 1kHz). Functional I dont' see a problem to implement this behaviour, but is the result effectively a coherent 1kHz data stream or is there a problem with the internal decimation/filtering? Does the sensor average the output values only for lower sampling rates, or also at the maximum setting of 1600Hz?Many thanks for your help!#mems #accelerometer #mems-accelerometer ##lis3dsh

Posted on June 19, 2018 at 13:26Hi All,please let me know how to find the algorithm for Step Count, Speed, Calorie burnt using the LIS 2dh and Lis3dh, we are getting X,Y,Z values.Thanks,utpal

Posted on June 15, 2018 at 08:28Hi,1. Write 64h in CTRL1 // Turn on the accelerometer // ODR = 200 Hz, High-Performance2. Write 04h in CTRL6 // FS 2 g LOW_NOISE enabled3. Write 20h in CTRL7 // Do not use low-pass filter for 6D, enable interrupts4. Write 40h in TAP_THS_X // Set 6D threshold (6D_THS[1:0] = 10b = 60 degrees)5. Write 80h in CTRL4_INT1_PAD_CTRL // 6D interrupt driven to INT1 pin interrupt set in SIXD_SRC register but didn't get any interrupt from INT1 

Posted on June 18, 2018 at 17:10Hi all,is there a way /sample to connect a MEMS mic (MP34DT01) via SPI to a STM32F103VB (no FPU)?We do not need each audio data sample. We just want to have a kind of audio level meter to detect any noise in a room.The PDM MIC SDK shows only samples with F4/F7 devices. Also the source codes are not available...Any ideas / suggestions, how to continue with my F103?Knut#mems-microphones #stm32f103 #fpu

Posted on June 11, 2018 at 11:35HTS221TR connecting via 3-wire SPI.Is there any official app. note for this interface.I suppose it is via connection MOSI and MISO through 10K resistor and then feeding it to a sensor.But I would like to get some official input from STM because I need it for a customer.Kind regards,Danko

Posted on May 21, 2018 at 06:53Hi  I am trying to get the VL53L0X using the api provided and the source code available on https://os.mbed.com/users/andcor02/code/vl53l0x_api/  which is just a copy of the VL53L0X api. I am using the STM32L432KC NUCLEO board with I2C connnection to a breakout board available on ebay -> https://www.ebay.com/itm/VL53L0X-Time-of-Flight-Distance-Sensor-Breakout-GY-VL53L0XV2-Module-for-Arduino/201718280643?hash=item2ef758b1c3:g:UPsAAOSwzXxaMlyn   The module works fine but the interrupt pin does not do anything. I am

Posted on June 14, 2018 at 21:38Hello, I do not understand why my LIS2DH stays at 188uA (basically the one in boot-up configuration) even if I configured it in Low-Power mode ?Here is my configuration :--LIS2DH Config---CTRL_REG1 : 0x2F (ODR 10HZ / Low Power / All Axis enabled)CTRL_REG2 : 0x0E (HP filter activated normal mode)CTRL_REG3 : 0x00CTRL_REG4 : 0x80 (BDU / scale 2G / High Res disabled)CTRL_REG5 : 0x42 ( Fifo enable / INt2 enable)CTRL_REG6 : 0x00STATUS_REG : 0xFFFIFO_CTRL_REG : 0x80FIFO_SRC_REG : 0x20INT1_CFG : 0x00INT1_THS : 0x00INT2_CFG : 0x2AINT2_THS : 0x06INT1_SRC : 0x00INT2_SRC : 0x00Help welcome.

Posted on June 14, 2018 at 11:00Hi,I am working on LPS25HB in our custom linux board. I have configured the sensor on I2C interface and able to read pressure, temperature.I am trying to check the interrupt on data ready event, high pressure event, low pressure events and on both high and low pressure events. I am able to get interrupt in all the cases except low differential pressure. According to my understanding threshold pressure is set by two registers THS_P_H and THS_P_L and Interruptthreshold(hPA) = (THS_P)/16. where THS_P = THS_P_H&THS_P_L. When I set THS_P less than the current pressure value then i am able to get the high differential pressure event., but if I am configuring the THS_P higher than the current pressure value then i am not able to get the higher differential pressure event.I may not able to get how low differential pressure event will occur please help me to solve this.Th

Posted on March 13, 2018 at 09:31The default application http://www.st.com/content/st_com/en/products/embedded-software/proximity-sensors-software/stsw-img008.html doesn't allow to use the multi-zone feature mentionned in this http://www.st.com/content/st_com/en/about/media-center/press-item.html/p3918.html. I believe I'll need to wait for the API source code to be released to get access to this feature. It turns out that as of today, there is no download available on this

Posted on June 11, 2018 at 14:40I have a weird problem with LSM6DS3. Right after power on I try to read the Who Am I register, via SPI. The return value is 0xFF, if I read it again it will send the correct value 0x69.In other words, in order to get the correct response for Who Am I, I must read the register twice, why is that?#lsm6ds3

Posted on May 17, 2017 at 21:36This document http://www.st.com/content/ccc/resource/technical/document/application_note/77/ed/e7/e1/28/5a/45/d6/CD00290365.pdf/files/CD00290365.pdf/jcr:content/translations/en.CD00290365.pdf provides information regarding an 'Activity/Inactivity recognition' on page 51ff. The section has been added in Jan 2017. I recently purchased a Sparkfun LIS3DH breakout and I cannot make this function work. Is there any pseudo code (what register has to be initialized how?)Regards

Posted on June 11, 2018 at 17:17Which IC should i use to detect Harsh Braking, Harsh Acceleration and Rash Turning?#harsh-braking/harsh-acceleration/-rash-turning

Posted on June 11, 2018 at 14:37Hi, the specifications of the  VL53L0X said that recommended input voltage is between 2.5 and  3.5VI have test it on a prototype at 2V and works fine at short range  (150 mm).  Which problems can i experience? If the only problems is  have a reduced range or less accurate measurements it's fine. It will be only on for a few samples  and it will be turned of through Xshut pin.#datasheet #vl53l0x #tof #low-voltage

Posted on May 27, 2018 at 11:00Hello,we have connected the lis2hh12 accelometer with our linux board using i2c bus. I am ableto read the raw x,y,z values from sensor using sysfs interface. How can i convert these raw values to actual acceleration(m/s2) values.Regards,SHAMMI

Posted on June 09, 2018 at 11:44[EDIT] Solved!  I missed where the app note mentioned that I have to set REG3's <I1_IA1> bit.  Once that's done, I get interrupts on motion.'App Note AN3308'Hello,I'm trying to enable interrupt on a LIS3DH using mBED, on a nRF51822.  Here's the program for reference:Main:  https://os.mbed.com/users/electronichamsters/code/AA_LIS3DH_I2C/file/3eaae3de806e/main.cpp/ LIS3DH.cpp:  https://os.mbed.com/users/electronichamsters/code/LIS3DH/file/c32d2b25d4c2/LIS3DH.cpp/ I'm trying to set the INT1 interrupt on moveme

Posted on June 08, 2018 at 23:30The IIS3DHHC is a triaxial accelerometer that outputs 16-bit data, 3-axis, �2.5 g acceleration data.So (5g)/(2^16 bits) = 7.63*10^-5 g's/LSB.arctan(7.63*10^-5) is essentially the same thing (small angle approximation in radians)and that converts out to 0.00437 degrees -- which is about 0.2622 arc-minutes -- which is about 15.74 arc-seconds.So the LSB represents about 16 arc-seconds of resolution -- is that correct?The other way I can talk myself into a solution is to eliminate 1 bit for the sign -- leaving 15 bits for a full scale value.  As an inclinometer, I'd never expect the value to exceed 1g -- so now we're down to 14 bits corresponding to 1g.arctan(1/10^14)=12.5 arcseconds.At the same time, I see that there is a 2%FS non-linearity -- thats 10-11 bits of data.  Where is the deviation the greatest, and how does that affect the usefulness of this devi

Posted on June 08, 2018 at 20:20With the part in FIFO streaming mode and a watermark set to 15, I poll for the watermark interrupt on INT1 and then burst 16 entries from the FIFO. I repeat this until I’ve acquired 2048 samples. When I do this, I occasionally see duplicate samples values in the stream.With the device on a shaker table driving a 100 Hz sinusoid, the captured waveform looks as expected. However, I occasionally see duplicate samples as shown circled in red on the accompanying plot. I’ve verified that the SPI bursts from the FIFO are completed much faster than the watermark interrupt fires. Attached is a SPI trace showing multiple transfers initiated by the watermark interrupt (WTM) to demonstrate that timing. I’ve also verified that duplicates can occur within a single burst which seems to rule out issues between bursts (e.g. the beginning of a burst reading the last sample from the previous burst). Interrupts to the CPU

Posted on June 08, 2018 at 17:58Can someone please clarify what the use case for the offset registers are on the LIS3DSH accelerometer?  These are registers OFF_X (0x10), OFF_Y (0x11) and OFF_Z (0x12).  The http://www.st.com/content/ccc/resource/technical/document/datasheet/23/c3/ea/bf/8f/d9/41/df/DM00040962.pdf/files/DM00040962.pdf/jcr:content/translations/en.DM00040962.pdfdoesn't really explain what they can/should be used for.#lis3dsh

Posted on June 08, 2018 at 16:57Hello,On the vl6180x datasheet, there is a paragraph (i.e. 2.7.4)  regarding Auto VHV calibration to regulate the SPDA sensitivity over temperature.But on the other side, there is this AppNote AN4626 regarding range vs temperature in the extended temp range (-30 to +85°C). This app note detail the constant offset (over the distance which is good) depending only the sensor temperature. So different temperatures will give you different measures or they have just turned off the Auto VHV calibration?Thanks for your clarification please?Ludovic

Posted on June 08, 2018 at 14:16Hi,I'm trying to get interrupt on the interrupt pin 1 of LSM6DSL module for the single tap event.Here are the registers I've configured (in order):   Address   Value    0x10         0x60       0x58         0x8e    0x59         0x08    0x5a         0x03    0x5e         0x40And yet I don't seem to get the interrupt.Should any more registers be configured?#lsm6dsl #single-tap

Posted on June 08, 2018 at 13:37I have been using the LIS3MDL with the ST breakout board and seems that the Latch interrupt request in the register INT_CFG (30h) has the description wrong.From my tests : 1: interrupt request latched; 0: interrupt request not latched Chan you check that this is a typo and fix it? I find misleading as well that in the app note AN4602 , the section 7 is about offset management but there isn't any mention of that in the datasheet of the device.  Kind regards#offset #interrupts #datasheet #lis3mdl #errata

Posted on May 31, 2018 at 12:07Hi,I have project for obstacle distance measurement where VL53L1X sensor is used and the microcontroller is Atmeag 328. I have downloaded API reference code. But there are lot of files which is really confusing me. I have used single sensor in my project. I have written software I2C to read basic register information from VL53L1X. I am able read the following registers properly.Model ID - 0x010F - Am reading 0xEA which is correctModel Type - 0x0110 - Am reading 0xCC which is correctMask Revision - 0x0111 - Am reading 0x10 which is correctBut to measure the distance there are lot of API's. It would be really helpful if i get any sample code or example code with atmel Microcontroller.Kindly help me.

Posted on April 09, 2018 at 11:11Hi friends,I have trying to install the VL53L1X GUI software in my desktop station but I cann´t do it because it shows me the next message: My OS is (windows 7 - 64 bits):I have also tried to install the program in another computers (Windows 10 - 64 bits) but the problem remains.Does anyone have this problem?Thanks and best regards.Jesus

Posted on May 07, 2018 at 17:27I'm developing an applications where an array of VL53L1X sensors would be used. During that development effort it became apparent that there were some timing issues while cycling through the sensors and when I expected them to complete ranging. I reverted back to the http://www.st.com/content/st_com/en/products/ecosystems/stm32-open-development-environment/stm32cube-expansion-software/stm32-ode-sense-sw/x-cube-53l1a1.html's example code while troubleshooting this issue. The P-NUCLEO-53L1A1 (X-NUCLEO-53L1A1 & NUCLEO-F401RE) development boards are being used with only the center sensor in place. The modifications made to the example code are the following:status = VL53L1_SetDista

Posted on June 07, 2018 at 20:55I am running LIS2DS12 with SPI using Arduino libraries and streaming data to microSD using the accelerometer FIFO buffer.Running with all 3 axes streaming to microSD works properly at 1600 Hz.When I switch to using the module to save the magnitude of the 3 axes, the resulting data are sampled at 800 Hz not 1600 Hz (testing by recording 300 Hz continuous waveform, which appears as 600 Hz).Running the module at 3200 Hz results in a triangle wav in the FIFO buffer.Full code here: https://github.com/loggerhead-instruments/TTFT/tree/master/Arduino/TTFTwav Are there limitations on the magnitude module sample rate?