MEMS and sensors

Posted on December 29, 2016 at 08:41Hello,I am using VL53L0X to perform range measurement. I knew there are C APIs and examples that provided by ST already. However, due to I am developing my project by other language, I think I should access to registers to achieving measurement.My problem is I don't know the definition and valid value of all registers. I tried to find relevant information on my.st.com and some technical forums, and got some useful clues. For example, I knew the address of VL53L0X_REG_SYSRANGE_START is 0x00 and I can configure different modes of range measurement by setting different values. Sadly, I cannot find a Spec that guides me to learn whole registers. So I will not achieve more functionalities by reading/writing registers.So could you please provide me some relevant information or Spec which describes all registers in VL53L0X ?Thanks!

Posted on June 21, 2017 at 12:34Hi,I'm having trouble with HTS221 device driver integration (for a FreeRTOS app). ST provides a platform independent driver (see http://www.st.com/en/mems-and-sensors/hts221.html ). But those drivers have functions which need to be remapped :         // the user must redefine the proper HTS221_WriteReg         #define HTS221_WriteReg(RegAddr, NumByteToWrite, Data)  HAL_WriteReg(HTS221_I2C_ADDRESS, RegAddr,      NumByteToWrite, Data)I want to use this driver with I2C but I don't find how, since I'm not use to play with drivers.Did someone already do this ? Or use another similary driver with an imx6 board ?QD

Posted on June 12, 2017 at 01:50Hello:What kind of problem would be caused if pins 2 and 3, marked as NC in the data sheet, were grounded? Would it cause the device to not function?Thanks...

Posted on June 21, 2017 at 10:25Hi, I am using LSM9DS1 IMU for one of our android-6.0 based product. As referred in below links,HAL Layer :  https://github.com/STMicroelectronics/STMems_Android_Sensor_HAL_Input Drivers:https://github.com/STMicroelectronics/STMems_Linux_Input_drivers After integrating above stacks, we are seeing some of the CTS failures.Please suggest us correct stack.Note: we are not using interrupts. Driver polls for events for every 1msThank YouBabu#accelerometer #lsm9ds1 #imu #gyroscope #i2c

Posted on June 19, 2017 at 17:41Hi at all,I am trying to implement gesture recognition with a SensorTile, to develope my firmware I started studying the BlueMicrosystem2 example, and so I was able to detect simple gestures as the wrist's orientation.Now I would like to recognize some gestures a few more complex, as draw a letter in the air or a symbol, what could be the way to implement this?I know that the open.mems library encodes a limited number of gesture in a code, as could I to recognize custom gestures and map them?Should I sample the data sensors by the SensorTile with regularity and compute them to recogize the gestures? or the Open.MEMS library can help me in this operation?Best RegardsTommasohttps://community.st.com/tags♯/?tags=sensortile%20bluenrg-ms%20firmware‌#sensortile-bluenrg-ms-firmware

Posted on December 12, 2016 at 14:48We need Linux device drivers of lsm6ds3 for kernel 3.7.6.Can somebody provide drivers

Posted on June 24, 2014 at 09:43Dear, What is the linearity error rate with VL6180X ? Tks and regards. A. #proximity-sensor #vl6180x

Posted on January 20, 2017 at 06:43I wonder that ST has plan to make another enhanced version of VL53L0x.VL53L0x's I2C speed and output rate is slow.If a spi interfaced device is made, I hope that it would support the daisy chain.Currently multiple sensor interface is very complex.And I hope that the API library is more simple and light.Additionally, a right angle mounted sensor is needed.

Posted on June 13, 2017 at 02:32Hi, I'm having some difficulty clearing the interrupt pin on the H3LIS100. I have it set to generate and interrupt on data ready. I am also using the LIS2D chip, which has a somewhat similar interface, and I can clear that interrupt by reading the INT1_SRC register (for an over threshold interrupt), but neither reading the INT1_SRC nor the actual data registers seems to clear the interrupt pin for the data ready interrupt condition on the H3LIS3100 chip. Going to power down state does clear the interrupt but that is not too useful when taking repeated data samples.

Posted on December 19, 2013 at 17:28In LIS3DH datasheet (Doc ID 17530) on figure 3 page 12/42 we can see: ''When no communication is on-going, data on CS, SPC, SDI and SDO are driven by internal pull-up resistors.'' What is the pull-up value? Are these pull-up still active if the LIS3DH is put in power down mode? #lis3dh-spi

Posted on June 13, 2017 at 06:03Hello:I am getting some bizarre values from this device, and maybe it's not configured correctly, or I am not reading it correctly.It appears I can send and read from the device. I can use the 'WHO_AM_I' and get back the value 32, which is correct. I then set the control register 1 at 0x20  to 0x27 = b00100111, which sets PM to normal, and x, y and z enabled. To check if the register has taken the value, I read it back, and it says 0x27.I'm assuming then that after doing this, I can just read the output registers at x,y and z, and  I am doing reads every 100ms (I do not have the interrupts configured at this point, and for now, not converting from two's complement)However, I am unable to get the output registers to change from 0xFF, no matter what I do with the board it's mounted on. I have tried some pretty hard 'nudges' and it will not change. Additionally, if I continuously read the status register, it is always 0xEE, which makes little sen

Posted on June 08, 2017 at 16:57Hi all,I am testing a LSM9DS1 module to replace a L3GD20. I get readouts for the gyro, the accellerometer and the magnetometer. However when I turn my pcb I can see value changes on the accellerometer and the magnetometer but the gyroscope signals (despite some noise) do not change. When I disable the individual gyroscope outputs then these go to 0 so I read the right registers. I also tried changing output rates, bandwidth and so on without success. I also tried the selftest, that doesn't change the gyro outputs either. Is my part broken?Thanks,André

Posted on June 12, 2017 at 20:42Hi,Some time ago I've succesfuly used lsm9ds0 (SparkFun) for 3D magnetic field readings. Today I'm trying to upgrade my device to use lis3mdl (MinIMU-9 v5 Gyro) but the magnetometer output is different than lsm and I don't know how to interpret it. It seems that X and Y axis woks simillar to lsm (positive and negative readings dependent on imu position) but the Z is always positive (eg 1500-4500 raw @ +/-4 gauss ) which I don't understand.I've used config from AN4602:M_CTRL_REG2,        0x40M_CTRL_REG1,        0xfcM_CTRL_REG4,        0x0cM_CTRL_REG3,        0x00I assumed that the magnetic field of measurement would be the same on lms9ds0 and lis3mdl but It seems that it's not or Am I doing something wrong?Thank you#magnetic-sensor #lsm9ds0 #lis3mdl

Posted on June 06, 2017 at 09:20I am having some problems when I try to get data from my sensor. I can read registers and get some data but I don't know how I should do the covnersion to get a real value.I am using an arduino and I found some libraries. Those libraries tend to use this format: x = ((int8_t)sensorData[1])*256+sensorData[0]; y = ((int8_t)sensorData[3])*256+sensorData[2]; z = ((int8_t)sensorData[5])*256+sensorData[4];Where position 0 of sensorData starts at OUT_X_L (28h) and goes up.Is this right? I have read something about left justified of LSB and I think it should be like:Is it the same?Apart from that, they use a formula to get mg values from the x,y and z values:x = (int32_t)x*1000/(1024*mgScaleVel); //transform data to millig, for 2g scale axis*1000/(1024*16), y = (int32_t)y*1000/(1024*mgScaleVel); //for 4g scale axis*1000/(1024*8), z = (int32_t)z*1000/(1024*mgScaleVel); //for 8g scale axis*1000/(1024*4)What is this about? where does this formula appear? Is it co

Posted on June 08, 2017 at 11:05Hello,I set the data rate (ODR) to 400Hz in high resolution mode with fifo stream mode enable of LIS2SH12.For 3 minutes measurement test, I excepted to receive 72000 (400 * 60 * 3) data for each axis, however I only received around 68220 number of data, which the data rate is around 379Hz (~5% tolerance).I also tested with two other LIS2DH12 samples, one is 378Hz, and the other one is 399Hz.Therefore I suppose the data rate has tolerance with it.Myy question are:1 Since the data sheet only provide the 'typical' value, any application note describe the tolerance of data rate?2 Is it possible to calibrate the data rate with register setting?Thank you very much.#lis2dh12 #odr #fifo #data-rate

Posted on June 12, 2017 at 01:32Dear sir/madam,I'm confused how can we change register concatenation data (eg. OUTX_H&OUT_L: FD5Ch) into a 10-bit data (eg. X: -676*0.061=-41mg)? Where -676 comes from and why this number is negtive?  [page 16 of AN4748 Application note]#lis2ds12-output-data

Posted on June 03, 2017 at 01:44In TN0018 'Surface mounting guidelines for MEMS sensors in an LGA package', on Page 5 it offers different guidance on land pad dimensions depending on whether the 'LGA pin spacing' is (a) greater than 0.2 mm or (b) equal to or less than 0.2 mm. If (a), it says oversize the land pads by 0.1 mm in both length and width; if (b), the land pads are not oversized.QUESTION 1: Does the phrase 'LGA pin spacing' mean open space between pins or pin pitch? I don't think I've seen a part with 0.2 mm pitch, to say nothing of less than that; the smallest microBGA parts I've seen have a pitch more than 0.2 mm. Anyway, the LMS9DS1 has a pitch of 0.43 mm, but its open space between pins is exactly 0.2 mm. Do we go by pitch, and oversize the land pads by 0.1 mm in both length and width? Or do we go by open space between pins, and not oversize the land pads? Or...?QUESTION 2: In this thread -- <LINK NO LON

Posted on June 05, 2017 at 15:21 Hi, I am working with LIS2DE12 accelerometer. Till now, I am able to read the raw data provided by the chip. Now, I have to detect free fall for the same. In the data sheet, I couldnt find any specific registers assigned for this purpose. The only thing I could find is that there are two interrupt pins available for the motion detect and free fall detect. But I dont know how to configure this interrupts. Can anyone provide me the steps for the configurations? How can I decide the threshold value for generating this free fall detect?? Thank you in advance!!!

Posted on June 09, 2017 at 05:24I have using DM00171283 and I have requirement to operate accelorometer sensor for FIFO,stream,stream to FIFO and FIFIO bypass mode with 1hz,10hz and 25hz frequency with i2c protocol. Moreover, I have also operate this sensor for normal,high and low power mode for INT1 or INT2. So, for that I have configure some register value but I have not get proper data from it. Is there any conversion formula for x,y,z axis to be read?.Following registers which I have configure:I2C_WriteByte(&ctrl_1,1,0x77);//low power 400hz I2C_WriteByte(&ctrl_5,1,0xC0);//FIFO enable I2C_WriteByte(&fifo_ctrl,1,0x40);//mode selection I2C_WriteByte(&ctrl_3,1,0x06);//interrupt generate    and then I have read all three axis valueI2C_ReadByte(&x_axis_L,1);I2C_ReadByte(&x_axis_H,1);I2C_ReadByte(&y_axis_L,1);I2C_ReadByte(&y_axis_H,1);I2C_ReadByte(&z_axis_L,1);I2C_ReadByte(&z_axis_H,1);so please provide some guidance for my

Posted on June 08, 2017 at 16:07I have configure all register of IIS2DH accelerometer according to requirement but can not able to sense motion. So,could you help me for configuration in all modes or at least example for one complete mode so I can understand better.Moreover, I would like to configure in all sensitivity values for 1hz,10hz,25hz. I also want some conversion formula for reading x,y,z axis if applicable to motion sensor.

Posted on June 08, 2017 at 07:55HI The main development is done on Android.The order company asks me to calibrate the acceleration sensor.Looking at the contents of the source, I can see 'st_calibrationtool'. Is this an APP?If so, where can I get the 'st_calibrationtool' app?If not app, how is it possible to guide how to calibrate the acceleration sensor?#lsm6ds3 #calibration #app

Posted on June 02, 2017 at 07:35Hello,I am using following resister setting to config the LIS2DH12 to generate FIFO watermark interrupt on INT1 pin, however the INT1 pin always stays LOW, I am not sure what I am missing.INT1 is connect directly to the MCU GPIO pin which set to input.Here are the register settings I'm currently using://Enable BDU, CTRL_REG4 = 0x80LIS2DH12_SetBDU(LIS2DH12_ENABLE );// Set to normal power mode, 10bit ACC data, CTRL_REG1 = 0x00, CTRL_REG4 = 0x80LIS2DH12_SetMode(LIS2DH12_NORMAL );// Full scale selection, CTRL_REG4 = 0x80LIS2DH12_SetFullScale(LIS2DH12_FULLSCALE_2);// Enable axes, CTRL_REG1 = 0x07LIS2DH12_SetAxesEnabled(LIS2DH12_X_ENABLE | LIS2DH12_Y_ENABLE | LIS2DH12_Z_ENABLE);// set ODR to 1Hz, CTRL_REG1 = 0x17LIS2DH12_SetODR(LIS2DH12_ODR_1Hz);// set FIFO watermark to 24, FIFO_CTRL_REG = 0x18LIS2DH12_SetWaterMark(24);// set Fifo watermark interrupt on INT1, CTRL_REG3 = 0x04LIS2DH12_SetInt1Pin(LIS2DH12_WTM_ON_INT1_ENABLE);/

Posted on June 08, 2017 at 04:31Hello:I am using the STLM20W87F temperature sensor in an application, basically, on a PCB to measure ambient temperature.Referring to page 10 of the datasheet, I have the sensor connected with a filter of 1000p / 10K. That output goes directly to the ADC input of the controller. My STM32F4 is sampling at 200 samples/sec. The Vref pin of the controller is at Vdd = 3.3V. At an ambient of 25C, the ADC values are around 2235 - 2260. This translates to a voltage of (2250/4095) x 3.3 = 1.81V. It seems to be high for the value in the datasheet that should be around 1.55 for T=25C. If I measure the actual voltage at the output of the STLM20W, it's pretty much spot-on at 1.59V.If I put my finger on the sensor, the counts should decrease, but barely moves. I even tried warm air from a hair dryer but nothing significant, maybe 100 counts lower. Ditto for taking some canned air and spraying on the device, the counts don't increase much, maybe 50 at most.Questions:1

Posted on June 07, 2017 at 23:23Hi everyone,For my application I used the LIS2DH12 MEMS in single click configuration. This is my setting:CTRL_REG1 = 0x5F                       // ODR=100Hz, Low Power mode, Z Y X axis enableCTRL_REG4 = 0x00                       // Full Scale(FS):+/- 2G, high resolution disable (low power mode)CTRL_REG6 = 0x82                       // Click interrupt on INT2 pin, interrupt active lowCLICK_CFG = 0x15                        // Enable interrupt single-click on X-axis, Y-axis and Z-axis CLICK_THS = 0x0D                        // Click threshold: LSB=FS/128 -> Threshold = CLICK_THS*LSB = 0.2G CLICK_TIME_LIMIT = 0x02            // Time

Posted on June 02, 2017 at 11:05Hi everyone !I'm working on the flightsense sensor thanks to the expansion  board X-Nucleo-6180XA1 and a satellite on a STM32F401RE. And I have some questions :I would like to know the accuracy of the sensor ?Also, I want to use it to determine a distance between the sensor and a target. I have implemented the example code and adapted it to my situation. I would like to measure the distance with at least 0.5mm of precision. But the sensor send only the result in millimeter by the I²C bus .Is it possible to have a more accurate measure ?Finally, I work on STM32F103 thanks to the SPL library and not with the HAL library. I tried to implement a code but unsuccessful ...Do you have an example with this library ?Thanks in advance,Best regards,Florian