MEMS (sensors)

Posted on May 01, 2014 at 11:01Hello,I've tried to calculate my gyro noise using AVAR (Allan Variance).The results I get are similar to the spec., but the dimensions are dps^2/Hz on my analysis and dps/Hz^0.5 on the spec.  If I calculate the square root of my results (Allan deviation) they are much higher than allowed.Have I missed something?Sincerely,Eran Horesh

Posted on April 30, 2014 at 15:53Hi,We have a MKI109V2 with different extension boards. Now the extension-board MKI135V1 is not working (both we have). We think we need to upgrade the firmware on the MKI109V2 which is running firmware version  2.4.4. Now while following the exact instructions in UM0979, the MKI109V2 does not enter DFU mode. We tried literally everything. Different PC's, drivers, methods and also checked the hardware connections on the PCB.My pc is running Windows 8.1 x64, however we tried in Win7 x64 and XP. #firmware #mki109v2 #upgrade

Posted on April 29, 2014 at 11:13hi, I get a much higher amplitude of noise in high sampling frequency (X-Axis, fixed chip): </colgroup> </colgroup> sample f Max Min 1000 1.171.875 -1.171.875 50 0.4882813 -0.09765625 is there any explanation? #h3lis331dl

Posted on April 29, 2014 at 09:56I have been planning a product development that needs magnetic information about the earth magnetic field and accelerometer information about the earth gravity field. I prototyped using the LSM303DLHC, but I do not see a successor Is there any, that has equal sensitivity? In some years from now about 1 million a year would be needed. I have one application question left after my prototype.  I need very accurate accellerometer info. The deviations at 1Hz data-rate led to the conclusion that I need to measure 1000 times a second to get sufficient samples for averaging towards my desired resolution. If the bandwith of the measurement is unchanged that approach would work. Can you confirm that increasing the data rate does not increase the noise bandwidth ?

Posted on April 29, 2014 at 09:48Hi friends, I am using LIS331DLH MEMS digital output motion sensor with msp430 controller. communicayion is I2C. I can read and write the register values of accelerometer. But I am trying to do tilting operation. I am not get expected result. It gives zero value in all coordinate(x_low,x_high,y_low,y_high,z_low and z_high). But the process is working fine.(no NACK in I2C communication). values only zero. please give the source of problem. #lis331dlh-sensor

Posted on April 28, 2014 at 14:30I want to do some measurements using STEVAL-MKI062V2. I want to compare the result with the result of my Kalman-Filter. But I can not find the file iNEMO_Suite_2.3.0_110913.zip anymore. I may delete the file before several months. Can someone help me? Can someone send me a copy of that file? Thank you all Best regards #inemo_suite_2.3.0_110913

Posted on April 14, 2014 at 01:46First I like this part and I LOVE the interface code that comes with it (stsw-mems004.zip from this page:http://www.st.com/web/catalog/tools/FM147/CL1818/SC1885

Posted on April 22, 2014 at 18:29Data sheet indicates LIS302 has been calibrated at VDD = 2.5VHow will the device perform differently if VDD were to be connected to 3.3V?Regards,Oscar.

Posted on April 15, 2014 at 03:56hi,   I can't get the interrupt after configuring the state machine of LIS3DSH. Could you give me some examples. My code as following:LIS3DSH_Write_Byte(CTRL_REG1, (u8)0x01);//enable SM1, SM1 interrupt routed to INT1LIS3DSH_Write_Byte(CTRL_REG3, (u8)0x48);//Interrupt signal active HIGH, Interrupt locked, INT1 signal enabledLIS3DSH_Write_Byte(CTRL_REG4, (u8)0x57);//X, Y, Z enabled, ODR = 50 Hz.LIS3DSH_Write_Byte(CTRL_REG5, (u8)0x00);//filter bandwidth 800 Hz, +/-2g, Self-test DisabledLIS3DSH_Write_Byte(TIM3_1, (u8)20);//Timer3 1000msLIS3DSH_Write_Byte(ST1_0, TI3);//SM1 state 1LIS3DSH_Write_Byte(ST1_1, CONT);//SM1 state 2 #tech

Posted on April 25, 2014 at 04:39It seems this is a very dormant forum to get help. I thought such a simple request would elicit 1 reply. I guess I will try another brand

Posted on April 19, 2014 at 11:26Hello, I have some questions.I'm using the H3LIS331DL accelerometer to calculate the distance and velocity of a RC Car.I'm using the TI's Tiva MCU(TM4C123BH6PM, ARM Cortex-M4F series) with 16MHz crystal.The connection between the sensor and the MCU is fine. I'm using SPI interface with 1MHz SPI clock. The sensor returns the 'Who am I value' which is 0x32. In other words, the hardware connection is reliable.///////////////////////// The following pseudo code is the register setup I applied to the sensor.Write Control Register1 0x3F                                                   Normal M

Posted on April 18, 2014 at 21:28I can't figure it out from the datasheet. I especially don't understand what REFERENCE is for and how its 8-bit value is interpreted.  Are there reference codes somewhere?

Posted on April 13, 2014 at 11:10Hello Community, I am encountering a problem while debug single and double click function on the LIS3DH. 1. If the LIS3DH is configure for single click event detection, the single click interrupt is generated when  a single input stimulus. 2. If the LIS3DH is configure for single and double click event detection, only the double click interrupt is generated when a double input stimulus, the single click interrupt never generated when a single input stimulus. What causes it, I am very worried. I would appreciate any help, thank you in advance! #lis3dh

Posted on April 07, 2014 at 13:27Hello I'm using a LSM330DL and have at 400Hz ODR of the both sensors data, and read this data to a PIC MCU using SPI protocol. I'm currently using the STATUS_REG register and poll the ZYXDA bit to determine if new data is available, and then I read the OUT_ registers. The problem of this solution is I'm continously polling the sensor and this consumes a lot of current. What I need is to keep both sensors and MCU in low power / sleepmode, and have a interrupt (DRDY?) to signal the MCU of new data available, so MCU will wake up, and read the data from the OUT_ registers, and go back to sleep mode. It seems to me that both sensors readings of the LSM are aligned (correct me if I'm wrong), so I thought that I only need one interrupt signal for either sensor, and then read the data from both. How should I setup and configure the LSM in order to get an interrupt to signal the MCU that new

Posted on April 01, 2014 at 20:11Hey, I have a design using the 3-axis accelerometer LIS3DH and during the thermal cycling test I noticed an ''issue'' on one of the 3 sensors I put in the chamber. The temperature coefficient of that sensor changes a lot during thermal cycles, depending on if the temperature is increasing or decreasing (see the curve attached). I know MEMS sensors may have fairly big TC but I would assume it's relatively constant so it could be compensated. Besides the TC issue the sensor seems still working properly.  I'm wondering if it's normal or actually something was going wrong. Attached please find the TC vs Temp curve showing the problem. Test conditions: chamber temp settings: -40C,5C,30C,65C,30C,5C ( each step lasts for 2 hours, whole cycle takes 12 hours ) sensor stays still during the test Regards, Qi #temperature-coefficient-

Posted on November 15, 2013 at 14:41Dear all,I think I am almost done with the this program, but when I plug after pprogramming my STM32F4 Discovery board. It gives an exclamation mark, (Code 10) generally. ''The I/O request was canceled.'' is written as well in the device status. I am attaching the programming made on KEIL uVision please help me out with this program.Umair Mukati. #usb #microphone #stm32f4discovery

Posted on March 28, 2014 at 14:02Hi, I received a couple of LIS3 samples last week and I'm using them in order to gain a little experience in the field of magnetometers. I managed to install the chip on top of a plastic pen in order to use it as a magnetic ''probe''. As i get near a magnet, I see a component of magnetic field rising to full scale. That's great but I noticed that the value remains in a sort of memory even if I reset o power cycle the device. Is this correct? Configuration for ctrl_registers: 1-0x5c 2-0x40 3-0x00 4-0x08 5-0x00 Reading data is done by:outXL=i2c_smbus_read_byte_data(fh,OUTXL); usleep(50000); outXH=i2c_smbus_read_byte_data(fh,OUTXH); usleep(50000); outX=(outXH<<8)|outXL; Output:47 Status ff rX 0.7050 rY -12.0000 rZ -0.1743

Posted on March 28, 2014 at 05:47I recently purchased the above. I am using Windows & software and wish to evaluate this product. Is there a datasheet, software, etc that applies to this? Thanks Peter

Posted on March 28, 2014 at 03:13Hello, I am new to ST accelerometers.And I am interested to LIS3DE or LIS3DH.I would like to know the mechanism of the self-testing mode.Anyone can help to send me a link of ST site, so I can learn from that?I tried to search by my self, but all are information of products, no explanation on the mechanisms.I read some other documents on internet, that the self test of some others accelerometers,A electrostatic test force is applied to the mechanical sensing element , so the self-test actually is almost same as you move the sensor in reality.So I want to know if ST 's Accelerometer works in same way. #self-test-self-testing-mechanism

Posted on March 21, 2014 at 14:34Hello,I am using accelerometer LSM303DLHC.I have made following settings:-1)      2g mode and data rate of 25Hz in normal mode.2)      All configuration register set as per initial requirement of accelerometer.3)      Interrupt on INT1 pin is set. For this CTRL_REG3_A is set to 0x40 value .4)      Threshold sets at 25 in INT1_THS_A register.5)      And  INT1_CFG_A  is set to 0x0A (interrupt on X and y Axis high event)After interrupt occurred measured all axis data and INT1_SRC_A register to know for what reason interrupt occurred.One reading from it is as X: FF00Y: FCE0Z: 39D0INT1_SRC_A: 6AINT1_SR

Posted on January 29, 2014 at 18:47Hi,after installing and compiling the iNemo Libraries, I wanted to know if there are any code samples relating the M1 module, even simple ones.Thank you #inemo-m1-sample-code

Posted on March 20, 2014 at 15:26Hello,I'm trying to work with LIS3DSH device with different ranges.I put the device on a table facing up, so Z axis should give me 1000mg reading, for all ranges.I configure the device to range 2g by writing to reg_5 0x00The raw value I got was 0x3ffe.The sensitivity for this range is 0.06mg/digit according to spec,So calculation is: 0x3ffe * 0.06 = 982.92 mg , close enough to 1000mg.I flipped the device to measure negative value.The raw value I got was 0xc001. according to spec I calculated 2's compelemt:0xc001 -> 2's complement -> 0x3fffSo calculation is: (-1) * 0x3fff * 0.06 = -982.98 mg , close enough to -1000mg.Then I tried to change range to 4g by writing to reg_5 0x08 (flipped the device back).The raw value I got was very similar to the previous one 0x4002.The sensitivity for this range i

Posted on March 20, 2014 at 08:48Dear sir/Madam, we are using lsm303dlhc. we don't know how to do calibrations .we are not understanding scale factor , offset and misalignment . so , i request you please give me the clear information regarding this issues. what are the formulas need to use calibrate the raw from sensor. Regards srinivas

Posted on March 19, 2014 at 17:25Hi,I am new to STM32 F3 Discovery. Wondering if this board can configure to support Windows 7/8 sensor and location platform. I am trying to figure out how to set it up to use Microsoft inbox driver.Thanks,Dick #stm32-f3-discovery

Posted on March 18, 2014 at 13:57we are  working with lsm303dlhc compass sensor and  interfacing with lpc3250. we are using linux kernel version 2.6.34. and have taken driver codes (accelerometer and magnetometer) from your site. its working only one particular direction with 0 to 360 degrees angles. remaning directions its giving only 250 to 360 degrees angles only. i mentioned below what are calculations are using accelValue[0]= accx/sqrt((accx*accx)+(accy*accy)+(accz*accz));     accelValue[1]= accy/sqrt((accx*accx)+(accy*accy)+(accz*accz));   pitch = asin(-accelValue[0]);   roll = asin(accelValue[1]/cos(pitch)); xh = magx * cos(pitch) + magz * sin(pitch);   yh = magx * sin(roll) * sin(pitch) + magy * cos(roll) - magz * sin(roll) * cos(pitch);  heading = 180*atan2(yh,xh)/PI; so, i request you can give me any sugge