Questions tagged [mems]

Microelectromechanical systems (MEMS) are very small electromechanical devices. Common devices made using the technology include accelerometers, gyroscopes and microphones.

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165 views

Why do accelerometers have holes etched in their masses?

I have been studying MEMS for a while now and I noticed that in almost every accelerometer design there are holes etched in the mass that is attached to the hinge. Why is that? A thing I thought of ...
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1answer
68 views

Heat generation rate to temperature

I have heatgeneration rate in W/m3 and I wanted to know how much temperature it can generate. The heatgeneration element is Platinum resistor for MEMS project. I want to know numerical relation? ...
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1answer
70 views

Is the frequency accuracy of this MAX7373 oscillator within tolerance?

I'm currently using a Maximum Integrated MAX7375 MEMS 8MHz oscillator (http://www.digikey.ca/product-detail/en/maxim-integrated/MAX7375AXR805-T/MAX7375AXR805-TCT-ND/4967873) as a clock source for a ...
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1answer
135 views

Is it a bad idea to switch from using a quartz oscillator for my timing circuit to using a MEMS oscillator? [closed]

I've read MEMS oscillators offer improved performance including phase jitter less than 500fs and frequency stability down to +-0.1ppm. It's difficult to switch from quartz because it simply works and ...
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1answer
1k views

how to solder MEMS microphone to PCB at home? [closed]

I would like to experiment with audio applications using MEMS microphone. The problem is i cannot think of a way to solder these microphones on a pcb as PCB prototype manufacturers that i know won't ...
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1answer
75 views

MEMS measurements of relative motion [closed]

I haven't performed any tests, but if I am in a train with velocity != 0, what will measure my IMU? (With IMU I suppose to have acc + gyr + magn). I am in a relative motion system, and my MEMS will ...
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2answers
3k views

Why can I read accelerometer and gyroscope data on the LSM9DS1 with SPI, but not the magnetometer data on the same device?

I'm currently working on a device that uses the LSM9DS1, a 9-axis motion sensor by ST Microelectronics. I’m using a PIC24FJ128GB202 microcontroller by Microchip, and communicating with the sensor ...
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1answer
214 views

MEMS 6 axis: acc + mag or acc + gyro?

I have a question which I can not give an answer even if it is some days I am thinking about that. In general a INS is made by an accelerometer + a gyroscope. Is it possible to obtain the same ...
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2answers
359 views

MEMS: why INS + GPS? [closed]

I have read in the Internet that in the most cases people prefer using INS (accelerometer + gyroscope) + GPS sensors. I have read they can compensate each other errors, but is it possible to obtain ...
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3answers
2k views

Is it possible to directly interface a MEMS ADMP541 microphone over I2S with any Microcontroller?

I have bought a MEMS ADMP541 Evalution kit to record voice samples with arduino controller MEMS microphone will produce digital o/p , I2S communication protocal My question is should I directly ...
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886 views

Simulate Gyroscope through MEMS accelerometer

Is possible to simulate the Gyroscope using Accelerometer values? I would like to make that in Android Context so using MEMS smartphone accelerometer.
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2answers
1k views

Signs of overheated smd chip

I am developing a board that has a couple of small SMD chips. I have successfully made a couple of working boards. Unfortunately I found out that one of the chips in my original design is going to be ...
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1answer
546 views

I2S output to a sound card

I followed this tutorial on building a microphone with two MEMS mics and a cheap USB sound card - it works pretty well, although I'm looking to upgrade the MEMS mics to some with better SNR and ...
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1answer
1k views

Accelerometer X/Y/Z “high events”

I'm looking at this accelerometer LIS3DH and the datasheet says that it could enable interrupt generation on X/Y/Z "high" or "low" events. What do these events actually mean? When are "high events" ...
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3answers
562 views

What is the general range of the structure oscillation frequency in MEMS gyroscopes and/or accelerometers?

Is there a general range for the oscillation of the internal structure in common MEMS gyroscopes and accelerometers? I'm considering the possibility of damaging MEMS sensors via externally introduced ...
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2answers
155 views

Is it possible a microphone sounds different when user hold it(or not)?

I am a computer-science student working on a signal processing project on smartphones based on recorded microphone signals. For my project, I need a really "reliable" recorded signal. The system works ...
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1answer
559 views

Calculating bits/sample from a digital MEMS microphone

I'm thinking of using a digital MEMS microphone in a project - looks like it would save on some parts: no need for an amplifier and ADC. The output from the microphone is PDM and I'd need to convert ...
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1answer
83 views

Avoiding heavy controller boards in a MEMS sensor circuit

I am very new to the circuit designing and the "Internet of things" world. I am trying to put together, for simulation purposes, a system that can pull information from a mems accelerometer sensor and ...
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1answer
1k views

How is an accelerometer initially calibrated?

Referring to a MEMS accelerometer, how is the laboratory, initial calibration being carried out? Is the gravitational acceleration involved as a reference, or is the actual analog data being ...
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1answer
3k views

1000 Hz+ refresh rate displays/ projectors? (for making volumetric displays)

I have found only few volumetric displays for the kind of effect I'm looking for. They can be divided by two characteristics into two separate groups each: rotating or moving screens, and moving ...
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1answer
1k views

Sustaining amp circuit for MEMS oscillator

A MEMS oscillator can be modelled as a lumped mass-spring-damper with a high resonant frequency and Q factor. According to Wikipedia "All commercial MEMS oscillators use electrostatic transduction". ...
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1answer
2k views

I2S interface ideas for multiple MEMS microphones

I plan on forming a microphone array with 4 MEMS microphones and doing the signal processing(beamforming) in matlab/C on my PC. MEMS mics i use have Digital I²S interface with high precision 24 bit ...
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4answers
5k views

Limits of dead reckoning using MEMS sensors

I'm trying to track body parts relative to a person's torso. I see quite a few questions about using MEMS accelerometers and gyros for dead reckoning, and they confirm my suspicions that various ...
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1answer
1k views

Direct interfacing of analog MEMS microphone to microcontroller ADC

I would like to sample the output of an analog MEMS microphone with an ADC embedded in a uC, sampling rate up to 1MHz. I don't care too much about signal quality (as I'm more interested in ambient ...
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1answer
1k views

How can use MP45DT02 and CS43L22 DAC with STM32F4?

I'm doing an application with MP45DT02 MEMS audio sensor omnidirectional digital microphone. I'd like to use a STM32F4 MCU to control it, but I don't know much about it. Can I take input from the ...
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0answers
173 views

Best possible specs for a MEMS mic in 2014?

I want to use the best MEMS mic that's on the market today (June 2014) in terms of audio quality. Since I know that "shopping" questions are forbidden, I'll phrase it like this: What are considered ...
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Dead reckoning with accelerometer & gyro. Possible?

I have a 3 axis accelerometer and a 3 axis gyroscope. I've been tasked with developing a dead reckoning system using this hardware. Essentially what's needed is for me to develop some code to track ...
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3answers
314 views

Erratic outputs from a second order system when input is too small

I'm modeling a simple Mass-Spring-Damper system to represent the torsional behavior of a micromirror. With references to some papers (this one mainly), I've constructed the model of a torsional mass ...
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2answers
940 views

Scaling down the sensitivity of an MEMS mic

I'm using an MEMS mic ADMP401, and the datasheet said, that the sensitivity form the chip is -46dbV, my question, how to can the scale it down, mean that I hear only really loud sounds?
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5k views

Reading noise from allan variance plot for MEMS sensor per IEEE Std 952-1997

I am following the Standard Sensor Performance Parameters from the "MemsIndustryGroup" to test some Gyroscopes: I conducted a test and plotted the square root of AVAR (Allan Deviation) against Time ...
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2answers
218 views

What does “spin on” mean?

In the begining of section 17.2 (chapter 17) of Digital Integrated Circuits: Analysis and Design the auther says: There are positive and negative resists. The use of a positive resist for pattern ...
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2answers
3k views

Contacting InvenSense MPU9150 auxiliary magnetometer

I am trying to reach InvenSense MPU9150 magnetometer using master mode disabled and bypass mode enabled. These values are written to and then confirmed from the MPU9150 : ...
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3answers
360 views

Attitude measurements with digital sensors falling out of synch

I am just starting to use digital inertial sensors (9 axis: accelerometers, gyros and magnetometers). Each 3 axis sensor has a sampling frequency I can set so that data goes into a FIFO and I can get ...
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2answers
2k views

Does MEMS accelerometer stability deteriorate over time?

I am wondering if over time MEMS accelerometer produces any worse output than when it is new? I found this research paper which acknowledges that temperature affect sensor output but there are no ...
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2answers
1k views

piezo vs mems accelreatometer for earthquake [closed]

if i want to detect earthquake based on acceleration, what kind of accelerometer is better? Piezo or MEMS
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3answers
5k views

How to detect angular position of a device mounted on a rotating wheel?

Is there a sensor that can sense whenever rotating wheel pass the ground? Like when mounted on a bicycle wheel rims, but without anything mounted on a bicycle frame - only mounting on a wheel it self ...

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