MEMS and sensors

Posted on October 19, 2016 at 17:30 Hello, I have a problem with the LIS331HH Sensor. The X and Y direction are send correctly to my microcontroller, only the Z value has an offset. I've tried different LIS331HH and the offset is not always the same, so I don't think that I have an error in my code, and when I change the resolution, I have the same offset, e.g. 2 m/s². Here are samples of my code: /* Registers */ volatile static uint8_t ACCEL_ADDRESS = 0x30; volatile static uint8_t CTRL_REG1 = 0x20; volatile static uint8_t CTRL_REG4 = 0x23; //CTRL_REG1 volatile static uint8_t MODE_NORMAL = 0x20; volatile static uint8_t ODR_1000Hz = 0x18; volatile static uint8_t Xen = 0x01; volatile static uint8_t Yen = 0x02; volatile static uint8_t Zen = 0x04; //CTRL_REG4 volatile static uint8_t FS_24G = 0x30; //For Result volatile static uint8_t OUT_X_L = 0x28; /* Variables */ volatile static int16_t X, Y, Z; static uint8_t Accels[6] = { 0, 0, 0, 0, 0, 0

Posted on October 25, 2016 at 12:01Hi,I am trying to find MEMS wireless  accelerometer. It can be an integrated device or a small board. Does ST has one ? Thanks for the help.  #mems #accelerometer #wireless

Posted on October 21, 2016 at 14:30 Hello, Recently I've been tasked with modifying existing code running on a system which contains a LIS2DH accelerometer. It should be pointed out that I'm used to high-level programming languages and this is my first venture into embedded development, so please forgive me if some of my questions are a bit... Dumb. I'm trying to access the FIFO buffer in order to look for a sustained period of low-g measurements. The existing code to find the number of lines in the buffer is: // Finding out the number of rows in the FIFO buffer GPIO_DRV_ClearPinOutput(LIS2DH_CS_PIN); // SPI enable, i.e. I2C disable FIFO_src_reg=acc_read_byte_blocking(LIS2DH_FIFO_SRC_REG); GPIO_DRV_SetPinOutput(LIS2DH_CS_PIN); FIFO_nbr_rows=(FIFO_src_reg&0b00011111); FIFO_nbr_rows+=((FIFO_src_reg&0b01000000)>>6); From what I understand, this means that we're retrieving FFS4 to FFS0 according to 2.3 in

Posted on October 14, 2016 at 09:14Hello, Is there a way to manually reset the LIS3DH? In our application, VCC is coming up *very* slowly, inherent to the system. I have the suspicion that the LIS3DH occasionally does not boot correctly as it fails self-test after boot. Power-cycling it brings it back to normal. Memory reboot (CTRL5:BOOT = 1) does not help. We have a clean reset source which takes care of the reset of the system. Is there another way to control the LIS3DH reset? There is a pin called 'RES' to be tied to GND which could stand for 'RESET' (or 'RESERVED'...). Thanks, Norbert

Posted on October 19, 2016 at 10:31Hello, I have been playing with the IIS2DH configuration and there are couple of settings that are not clear for me, for example: - what is the I1_DRDY2 used for? - similarly I'm not sure about I1_AOI1 vs I1_AOI2 interrupt functionality - in CTRL_REG6, as per spec I2_INT1 and I2_INT2 redirect interrupt functions 1 and 2 respetively onto INT2 pin, but what is the actual difference between function 1 and funtion 2? It would be great if someone could clarify it. Thanks. #iis2dh #drdy1 #drdy2 #aoi2

Posted on October 13, 2016 at 15:47HiI have 2 LPS25HB pressure sensors. I moved them from exact the same level to another level. The readings from both sensors are different. The start points are different and the slope of the value change is also different! However, i just programmed to read the value out without editing any reference or offset, or differential setting. Can i correct the results by editing some registers, if so which registors?Thanks Rui

Posted on October 13, 2016 at 13:40Hi , I'm newbie with stm32f3 and i want to send the accelerometer data to my raspberry pi 2 through USB , please i need some help  ? 

Posted on October 11, 2016 at 21:34The datasheet specifies that it has 16 bit output data, but the data that i get out of the registers are 12 bit ie first 4 bits of High Byte is always 0. Am i doing something wrong here or is the effective resolution only 12 bit ? #lis331 #lis331hh

Posted on October 11, 2016 at 12:21I need connect 3 LSM303AGR in the same I2C bus. Is It possible? How do I change the I2C Address?   #lsm303agr #i2c

Posted on October 30, 2013 at 03:02Are the specs for the ADC in the LIS3DH available?  I'm particularly interested in input voltage range, input current, and recommended capacitance for ADC inputs.

Posted on April 08, 2014 at 16:13Hi,Is there an easy way to 'factory reset' the LIS3DH?Does a simple power cycle do this?I looked through the data sheet and app note and could not see this defined there.Thanks #lis3dh-reset

Posted on October 04, 2016 at 12:47Hi How can I start with LIS2DH12 accelerometer programming , is there any tutorial for beginners about the registers ,how they work and how to write a program for them  ? hanks for help #accelerometer-lis2dh12-configure

Posted on September 30, 2016 at 07:49Does anyone know how to change the standard mode to 2V8 mode?I could not find the details in the VL53L0X API manual. #vl53l0x

Posted on October 03, 2016 at 18:03Hi, in datasheet for LPS25HB ('DocID027112 Rev 3'), page 27, the register 'RES_CONF (10h) Pressure and temperature resolution' is described. Question1: Is the 'Nr. internal average' (table 18) applicable for One-shot mode? Q2: If it is so, would be selected Nr.internal average influence on conversion time for One-shot mode at all? Q3: How long would be conversion time in One-shot mode? If there is concerned above influence (see Q2), what is the conversion time, when Nr.internal average=8 and when Nr.internal average=512? Best regards. #lps25hb #pressure-sensor

Posted on October 03, 2016 at 16:26where can I download iNEMOEngine_LI3 source code. I can't find a link to it

Posted on October 03, 2016 at 12:51Distance measured by the sensor is direct value or averaged value? If it is averaged value means then in what way they are averaged ? Is FOV takes major role in averaging?

Posted on September 27, 2016 at 15:34I am using the L3GD20H in an application where I am measuring the angular velocity of a pendulum.  I want to calculate as accurately as possible the kinetic energy.  I have calibrated for gyro zero-offset drift, however non-linarity is causing slightly different reading when the pendulum is rotating clockwise and counter-clockwise.  This is within the range indicated by the datasheet. My question is, how stable is the non-linearity of the gyro with respect to time, temperature etc?  Can I expect to be able to calibrate the non-linearity once for each L3GD20H device and not have to recalibrate in the future? #l3gd20 #non-linearity

Posted on July 19, 2016 at 21:00I had already multiple times the problem that the accelerometer sensor is not providing data anymore. It is connected via SPI, commands like the who_am_i works, however the XYZ data is all zero or just some frozen values. Sometimes only one or two axis, mostly all three.Re-initializing everything does not fix it, only a power disconnect fixes it.How can I do a complete reset, which commands? #lsm303agr

Posted on April 21, 2015 at 17:00Hi I'm just bringing up a VL6180x mounted on a VL6180X-Satellite board with bit banging software. Everything has gone well so far, writing and reading registers etc, for proximity only application. The ranging output goes to a minimum of 18 at 100mm and shows a system error of 2? reading the RESULT__RANGE_STATUS register. I found the AN4545 with the private register writes but this seems to differ slightly to one of your earlier replies to other queries? You have extra register writes! Is there a further update to this list. Also I'm interested in being able to detect approach up to 400mm away and then going to fine approach as the device nears the target. Is this possible? Regards Dave B

Posted on September 26, 2016 at 07:51Hi We manufactured 200 PCS sensor base on HTS221, Now when we test them, Some of them will stop working when they reach up to 80-90 degree C Base on Datasheet, it works in -40 to +120. How they stop working : Some will report invalid degree and it will remain constant. Some will not answer to I2C. and so on. We used SF2 cap, and it's inside the enclosure, so there is no chance for temperature shock. We used our custom heater for +70/+80/+90 degree C adjustment and testing. One of them failed while it was on the back of the car window, In direct sun. Any suggestion ? Does ST test all of the sensors for full temperature/humidity range ? Thanks. #hts221 #hts221-hts221tr

Posted on August 30, 2016 at 11:06What document have package marking information for LIS2DH12? WHO_AM_I =33h same as LIS2DE12 or LIS2DE. Thanks. #lis2dh12

Posted on September 21, 2016 at 17:23I have a quick question about LSM303D. I would appreciate it if you would provide me some suggestions.I am using SPI communication to exact all the magnetic sensor data in 100Hz. ( I configure the SPI baud rate to be 230400bps.) In order to increase dynamic range/signal to noise ratio, I am trying to change the sensitivity based on the received magnetic sensor data value. For example, if the sensor value is getting smaller, I will want to change the scale smaller. If the sensor value is getting close to the threshold, I want to change the scale larger to avoid overflow. Specifically, I am modifying the LSM303D_CTRL6 register value in real time to achieve this objective. What I observe is that there is a period of oscillation of data (or garbage data) almost every time that I changed the sensitivity. Currently, I am simply writing to the register without any wait or acknowledgement. A

Posted on September 20, 2016 at 22:04Here's a snapshot from my logic analyzer showing valid data for the X axis, but zeros for Y and Z.

Posted on September 20, 2016 at 21:12Hello, I am using the AIS3624DQ accelerometer, and I am able to get valid readings from the X axis, but the Y and Z are returning zeroes.I can read out the CTRL_REG1 register, and I see that X, Y, and Z are all enabled.  For whatever reason, X is reporting valid data, but not Y and Z.Any insight?  Or Errata I should know about?Thanks! #ais3624 #accelerometer #stm32

Posted on April 06, 2016 at 13:55Hi everybody, I use a LIS331 with I2C communication. I can read and write the configuration register (CTRL_REG1 for example) but when I want to read any data register, the read value is always zero. CTRL_REG1 value is 07h, therefore the axis are enabled. I have tried to read STATUS_REG and the value is zero. Anyone has had this problem ? Have I forgotten a step in configuration or something like that ?   Thanks in advance.    #lis331