MEMS and sensors

Posted on June 12, 2017 at 12:08Hello, I would like to use the LIS3MDL magnetometer in single measurement mode to reduce my overall current consumption.I've found some useful informations in the AN4602 Application but I'm still missing something.The turn on time, from wakeup command to data availability, is specified (as a function of the operating mode) but the current consumption during turn on is not given.What value should I use for my calculations?ThanksGuillaume#power #lis3mdl

Posted on January 12, 2016 at 13:15How may i know about self-test, what is the procedure after enable self-test for each one, and what kind of data will there that i have to use for further analysis, and how. #self-test

Posted on August 30, 2017 at 19:09I am trying to test the magnetometer on LSM9DS1 sensors.Can I apply the same self-test range-values than the LIS3MDL compass to check the LSM9DS1? The fact is that the magnetometer in the LSM9DS1 seems to be a LIS3MDL (same documentation of the registers). I am using the http://www.st.com/resource/en/application_note/dm00136626.pdf, where the self-test procedure is explained in page 19, with self-test ranges indicated in table 17.I already implemented a self-test procedure for the LSM9DS1 and I obtained for one sensor on which I suspect a problem the following values:Average_X_self_test - Average_X_no_self_test = 2551 (no scale) = 0,93 gaussAverage_Y_self_test - Average_Y_no_self_test = 2682 (no scale) = 0,98 gaussAverage_Z_self_test - Average_Z_no_self_test = -415 (no scale) = -0,15 gaussAnd for a second sensor that seems ok, the values are:Average_X_self_test - Average_X_no_self_test = -4476 (no scale) = -1,64 gaussAverage_Y_self_test - Average_Y_no

Posted on July 31, 2017 at 12:56Hello, I want to do a self test to lsm9ds1.Is there any file that explain how to do it?I found some sources  but nothing official.If there is not official file, i have some questions:Is the sensor can't be in motion at the time of the self test?Is the sensor must be in specific position?How to make self test to the magnetometer?Thank youYair Sarid#self-test #lsm9ds1

Posted on July 07, 2017 at 02:25Dear sir/madam,I'm confused how the Threshold decodeing(degrees) comes like shown in LIS2DS12 datasheet, page 31. When 6 stands for 80 degrees and how 6 comes from?I try to use 60 degrees threshold and I can read accurate each axis value now, but how can I compare 60 degrees with accurate output values for xyz axis?Thank you very much.

Posted on September 03, 2017 at 10:27Hello sir,HELLO EVERYBODY,I have a question about LIS3MDL.   Expecially, interrupt problem.I am using LIS3MDL below sequence.=================================================================================1. In normal circumstance, I get a basic data for reference threshold of Interrupt.Normally, 0.4 ~0.5 gauss.   And plus 0.1 gause for offset value.2. I put in the data for Threshold value. And I enable the interrupt. 3. Wait the interrupt (basic data[0.4 ~0.5 gauss] + offset[0.1 gauss])4. If interrupt is happened, the interrupt signal wake main CPU(stm32f103rct6)problemI checked how many times interrupt is happened, in normal circumstance(0.4 ~0.5gauss)In our office, interrupt is not happened.   ( It is good because our office does not have the change of geomagnetic)Outside, interrupt is happend eventhough there are nothing to change geomagnetic.==>I wonder why the interrupt is happened outside?  &n

Posted on July 13, 2017 at 14:06I did not quite understand from the pdf when reading 32*3 samples from the FIFO in SPI mode, can I set the SPI starting address at OUT_X_L (28h) with the SPI's MS bit raised and then read in a constant SPI read stream (single message) all of the 192 bytes?Or do I need to read the SPI starting with  address (28h | 40h) in 32 different messages?I saw in a previous post, that you can use the FIFO only in 10bit mode.Is this true?#lis2dh-fifo-spi

Posted on July 22, 2017 at 08:34I am using LIS3MDL and is there any way to offset the interrupt threshold values by changing the Offset Registers? What I mean is suppose my surrounding environment z-axis value is 50uT and if I want to offset it to 0 then I can write 50uT to the OFFSET_Z_REG register. This works fine. Now since my Z-Axis is offseted to 0, if i set the interrupt to 10uT, then even though OUT_Z register  shows 0, the Interrupt is triggered which shouldn't happen until 10uT.  And suppose if i set Interrupt threshold to 60uT, then when OUT_Z  goes to 10, then the Interrupt is triggered.I have set the Full-scale configuration to +-4 gauss.What i understood is that any changes to OFFSET_Z_REG is affecting only the OUT_Z register and not the Interrupt Threshold. Like the z axis value in OUT_Z, is there a way to offset interrupt too?   #interrupts #lis3mdl #lis3mdl-offset

Posted on June 22, 2017 at 15:50Hi, I'm new here and I am new at working on mems.I have a LPCXpresso1549 evaluation board and a Steval-MKI172v1 mems that implements a lsm303agr chip. I'm working on mbed platform and I need to read values from accelerometer but I tried a lot and cannot read anything.I connect pins for SCL and SDA, 3V3 to the VDD pin, the GND, and two digital pins to the CS and CS_A (chip select on lsm303agr). I don't know what address my lsm303 has and I can't understand what address I need to write on registers :(My code is:&sharpinclude 'mbed.h'&sharpdefine ACC 0x00&sharpdefine CTRL_REG1_A 0x20&sharpdefine CTRL_REG2_A 0x21&sharpdefine CTRL_REG3_A 0x22&sharpdefine CTRL_REG4_A 0x23&sharpdefine CTRL_REG5_A 0x24&sharpdefine OUT_X_L_A 0x28&sharpdefine OUT_X_H_A 0x29&sharpdefine OUT_Y_L_A 0x2A&sharpdefine OUT_Y_H_A 0x2B&sharpdefine OUT_Z_L_A 0x2C&sharpdefine OUT_Z_H_A 0x2Dtypedef struct Plane {   

Posted on June 22, 2017 at 09:56Hi,I am planning to use  LSM9DS1 9DoF sensor in our project. As per datasheet table #2, Least significant bit for I2C address is [SDO_   A/G or SDO_M ]= SA0.From this information & Table#19, I will be able to identify I2C address for Accelerometer and gyroscope.How can I set address bit 1 of SAD[1]/SA1 to identify Magnetic sensor I2C address? Awaiting for earliest response.Regards,Ritesh.

Posted on July 27, 2017 at 07:27Hi,I am 'LSM6DS3US' sensor only for Gyroscope in I2C mode.I have the following queries related to the Gyro:1. After Power On is �20ms� delay needed for bootup procedure to load trimming parameters.Is this delay mandatory?2. As per the document(AN4650) �the starting condition must be stable for at least 200 ms�. Is this describes I have to put the delay mandatory of 200ms(includes Power On/Power OFF) before reading the Gyroscope Data.3. Also if I set the ODR to �52 HZ� do I need to discard the first two samples of Gyroscope Data in my application?4. Shall I use the �BDU� feature to reduce the above delay in bootup procedure. What is the optimal way in reducing the delay and reading the Gyroscope?5. If Possible share me some example code using I2C mode.Regards,Purusothaman R#gyroscope #lsm6ds3us #software-i2c

Posted on August 21, 2017 at 16:33Hello.I am curious about the power consumption of the LSM6DS3. The LSM6DS3 can set ODR independently.However, the power consumption when the ODR is set independently is not listed in the Application note.Only <Accelerometer only>, <Gyroscope only> and <Combo [Acc + Gyro]> are shown in Table 6.I wonder how I can calculate it.If the Accelerometer's ODR is set to 208Hz and the Gyroscope's ODR is set to 25Hz,how much power does the sensor consume? #output-data-rate #lsm6ds3 #power-consumption

Posted on September 01, 2017 at 10:37My previous MEMs system is based on LSM6DS3(+-2000dps scale). According to my experimental data, if I rotated the sensor slowly by hands, the integrated attitude of gyroscope data was quite accurate and acceptable. If I rotated the sensor at 300 DPS, the attitude error might be above 20 degrees in 2 seconds. That's a lot! According to the attitude algorithm, the calculation error won't be larger than 2 degrees per hour. I checked the attitude code once and found nothing wrong. So is the LSM6DS3 capable of this kind of situation which sensor is spinning faster than 300 DPS? 

Posted on August 29, 2017 at 18:30Hi everybody!Just a short question about the VL53L0X Time-of-Flight ranging and gesture detection sensor.The datasheet mentions a 'Programmable I2C address'.Is it possible to change the default I2C address to another address permanently?Will the new I2C address be stored in the VL53L0X permanently?I mean if i run the VL53L0X through a complete power cycle:- VL53L0X on... set the new I2C address- VL53L0X off- VL53L0X on... Will the new I2C address still be available?Best regardsTobi

Posted on August 30, 2017 at 18:18I came from using LSM9DS0. I'm a bit confused about how does the FIFO work for gyro and acc in 9DS1. It seems that the FIFO control register only allows me to set 1 watermark/threshold value. Does that mean it applies to both gyro and acc? 9DS0 allows me to set different thresholds for each sensors. I'm a bit confused about how to setup the interrupt service for the FIFO. In 9DS0, gyro fifo interrupt can be set directly on DRDY_G pin and the acc fifo interrupt can be set on INT1or2/XM pin. In 9DS1, I can't really tell from the datasheet which sensors is being set on INT1_CTRL and INT2_CTRL. Does enabling the INT1_IG_G  set the gyro interrupt in INT1_A/G pin and automatically set the acc interrupt on to INT2_A/G?#lsm9ds1

Posted on August 30, 2017 at 15:21I am wondering why the LSM6DSL does not have a design tip for calibration like the LSM6DS3 (DT0053, DT0059) are these documents not valid for the LSM6DSL ?

Posted on August 29, 2017 at 18:35Dear all,I'm writing .cpp driver for Arduino for the LIS3DHH but something seems wrong.No replies from the accelerometer.Do you have any suggestion on the SPI correct communication task reading my files?

Posted on August 30, 2017 at 10:17Hi, I would like to know what shock, acceleration and vibration values the LSM6DSL sensor supports. Has anyone used the core IKS01A2 that carries this sensor, with the F401RE? Thank you.#lsm6dsl

Posted on August 30, 2017 at 10:17Please tell me(i capture pic about it)

Posted on August 26, 2017 at 01:46I'm trying to configure an LSM6DSL device to provide the wrist tilt interrupt on INT2 and the inactivity interrupt on INT1.  The tilt interrupt appears to work fine.  With inactivity however, I see the interrupt when the part is inactive, but I get it again when it starts moving.  I feel that it is combining the wake up and inactivity interrupts together, but I have the wake up interrupt disabled.This is how I configure the registers after a reset (using CTRL3_C = 0x01):(general)CTRL1_XL (0x10) = 0x62(wrist tilt)CTRL10_C (0x19) = 0x84DRDY_PULSE_CFG_G (0x0B) = 0x81(inactivity)TAP_CFG (0x58) = 0xE0WAKE_UP_DUR (0x5C) = 0x02WAKE_UP_THS (0x5B) = 0x03MD1_CFG (0x5E) = 0x80With MD1_CFG set to 0x80 (only the INT1_INACT_STATE bit set, and the INT1_WU bit cleared) why would I see interrupts when the device is moved around?  Am I missing some register setting?Thanks,Angelo#lsm6dsl

Posted on August 15, 2017 at 14:57LPS25: Extrem temperature dependant pressure output

Posted on August 24, 2017 at 09:21Dear ST staff,I'm looking for the LIS3DHH accelerometer on some distributor but no one seems to have it available?Can I buy them directly from ST?It's for a incoming project that is going to produce 3000 pieces for year immediately.Thanks

Posted on August 23, 2017 at 16:50Hi!, I'm trying to do bring-up of a board that has the LSM6DSL and other sensors in its sensor hub. I can read and write to other registers except for CTRL10_C (19h) and MASTER_CONFIG (1Ah) which I can only read and they are in its default values. I want to write to above registers to activate he sensor hub functionality. Both sensors in LSM6DSL are in its default power-down status when I try to write to the mentioned registers. Could I be missing something else to be able to write to the registers? Thanks!

Posted on August 24, 2017 at 11:14I have a design in which I have to put the line from SA0 to GND (this is mandatory since the alternate I2C address is already used on my I2C bus). However, the internal pull-up of SA0 seems like it can not be disabled, implying that my system will always have an extra power consumption of around 100uA@3V. How can this be avoided?It is shocking that in other devices of the family, such as the LIS2HH12 that I used before in my design, it is possible to disable the pull-up by software. Why has this feature been removed?

Posted on August 23, 2017 at 14:55Register 0x2A and 0x2B are aways fixed when I read back register even with restarting the sensor power.Config before reading back register:Register_0x20=0x83: (active mode, continuous update, output data rate: 12.5HztRegister_0x21=0x01: (Boot normal mode, Heater disable, start of new dataset)Register_0x22=0x84: (DRDY active low, PP_OD push pull, Data Ready signal available on pin 3)The dataready pin is also always low, command Who AM I works fine.Content of register 0x2A: 0x18;Content of register 0x2B: 0x80;Does anyone has the same pb ? Is the chip dead ?