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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Piezoelectric circuit behaviour
I am trying to study the piezoelectric material behaviour using S-Edit. Here, the force acting on the piezoelectric material is mapped to current. In the waveform viewer, I can see the current graph (...
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What is causing the digital output of my MEMS pressure sensor to decrement continuously?
I'm a lowly mechanical engineer so bear with me. This problem has been the bane of my existence.
I'm using a temperature-compensated barometric pressure sensor in a fluid-contacting application. ...
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Can I use three PDM MEMS microphones with an ESP32, even though it already uses an I2S DAC?
For my design, I need stereo audio output (2 MAX98361 ICs work best imo) and three microphone inputs. I figured, the easiest way to do this was to use 3 digital MEMS microphones, but i don't know if ...
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External synchronization of a AD MEMS acceleration sensor (ADXL355)
sadly, the AD help page was not very helpful therefore I'm posting here with the hope that the collective intelligence here can help me with my problem.
I'm struggling with the external ...
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How do I connect the CS pin on an ILPS22QS sensor to enable I2C?
Should I connect the CS pin on an ILPS22QS sensor to enable I2C?
In order to enable the I2C interface, on page 25 of the datasheet it says that the CS pin of SPI must be tied high by connecting it to ...
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What is the point of the connection to ground, with resistor, on the inverting output of this MEMS microphone?
For reference, the datasheet I am referring to in this post is given by this.
I was wondering whether anyone could clarify the point of connecting the inverting channel of the succeeding stages of the ...
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ZL30251 phase aligned
I just want to confirm whether the part zl30251 has phase aligned outputs? If not, can it be aligned?
Also, I can confirm that both the outputs are LVCMOS.
Can you please help me with this?
Also, i ...
user220456
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Where do you need high frequency switching of high AC-currents?
Is there any application or piece of electronics that requires high frequency switching of high AC-currents?
Due to the (high) AC-current, application of a transistor would be discouraged while the ...
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Load capacitance of mems oscillator [duplicate]
I am using 88E1512-A0-NNP2I000 in my design. It requires 25MHz clock signal on its XTAL_IN pin.
I will be providing the required 25MHz clock using ASTMLPE-18-25.000MHZ-ER-ET.
In the datasheet of ...
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What is the correct maximum sample rate for the MPU-6500? Most of the internet says 32kHz, the datasheets say this isn't likely
The MPU-6500 is an IMU IC from InvenSense/TDK that superseded the (legendary, by now) MPU-6050 IMU IC. Supposedly, the major performance improvement was that it has a sample rate of 32k samples a ...
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How to get audio frequencies from mems microphone in PC oscilloscope
I'm fairly new to electronics/signal processing and I'm stuck on trying to obtain frequencies from an Adafruit SPW2430 MEMS microphone. I tried plugging the microphone to a Hantek 6022BE PC ...
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Simple data over sound solution
I'm designing an access control and I'm evaluating different technologies to make the device unlock the access.
One of the technologies I'm studying is integrating a microphpone in the device and ...
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ADXL345 Accelerometer data rate vs bandwidth
I recently started working with the ADXL345 Accelerometer and got a bit confused on what's the difference between the data rate and bandwidth.
From the ADXL345 datasheet p14, we can see the different ...
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I2S slave communication without an MCU - how to generate the clocks?
I am designing an audio amplifier circuit which uses an I2S digital MEMS mic (INMP441) for picking up voice signals and an I2S class-D amplifier (MAX98357A) for amplification.
I have attached the ...
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I2S communication
I am designing an audio amplifier circuit which consists of an I2S digital MEMS mic (INMP441) for picking up voice signals and an I2S class-D amplifier (MAX98357A) for amplification.
Both these ICs ...
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What generates the torque to rotate this micromirror around the _vertical_ axis?
I can see current in the coil could interact with a magnetic field could cause the coil to rotate around the horizontal axis (flexures 310 and 312), but what forces are making the inner micromirror ...
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Which is the best sensor to detect accident in a vehicle eg. A car?
I did some research on this and came across MEMS sensors, there were quite a lot of them, but most of them acted as a gyroscope which would give output for left-right front-back tilts. I want an ...
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System being subject to vibrations and G-forces : Crystal Oscillator or MEMS?
I'm planning on making an audio system that will be used in vibration-inducing environments (roller coaster rides that can reach up to 5/6G peaks and public transportation systems). One of its ...
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MPU9250 Gyro Calibration-Offset
I'm working with mpu9250 gyroscope and I got fine measurements for beginning period (few minutes). I calculated offset at start in manner to average sum of first 1000 results from mpu9250 gyro. But If ...
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Durability of SMD MEMS pressure sensors in pure oxygen enviroment
I have a question regarding durability/reliability of COTS SMD mems pressure sensors in oxygen rich (basically 100%) atmosphere under pressure of 1bar/1atm and temperature around 20C/293K.
Sensor ...
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What do these question marks next to heater resistance mean?
This is from a sensor called MQ306A used for sensing gas.
My problem is that this same series of sensors from the MQ category have the same tin dioxide layer but they claim to sense various gases.
How ...
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Do MEMS accelerometers have a lower frequency limit?
Being a higher level programmer by education I have no deeper knowledge of electronics and electromechanics, so feel no obligation to answer this.
I'm wondering about MEMS accelerometers. I heard a ...
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Si5350 Driven by MEMS oscillator
I'd like to drive an Si5350 with a MEMS oscillator instead of a crystal for environmental robustness purposes. The Si5350 FAQ says that a CMOS input may be used instead of a crystal so long as the ...
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STM32 MEMS microphone - weird output
I have an STM32f407vgt development board that has a MEMS microphone (MP45DT02) on it. I aim to take processable data from this microphone. STM32 provides PDMtoPCM conversion library and I2S ...
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How to convert pixel map to voltage/angles?
My end goal is trying to get something rendered using lasers and a MEMS scanning mirror. There are not that many resources online for this, but it seems like the basic idea is pretty applicable to ...
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Signal conditioning of the acceleration data from the ADXL 354
My project consists of the detection of a leak in a pipe using the vibration methode.
I am using the MEMS accelerometer ADXL354.
I selected the +/- 2g range.
My problem is that the static acceleration ...
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How are objects rendered with a MEMS mirror for AR?
This question is an intersection of both hardware and software. I am trying to understand the theory of AR technology, but hitting some roadblocks and cannot find any good online resources that talk ...
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What changes when you modify gyro/accelerometer/magnetometer range?
In hobby-grade MEMS IMUs and MARGS such as MPU-6050, you can change certain registers on the chip and modify the sensor's range. For example 2 g or 8 g for an accelerometer. Of course, because the ADC ...
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Frequency response of accelerometer MMA7361L
In order to create the model of the MEMS accelerometer MMA7361L I'm going to need the frequency response of it, but I don't have access to the university lab to use the oscilloscope because of the ...
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What is the output voltage and current necessary to operate the MEMS mirror?
I am trying to develop a driver to control a MEMS mirror by Mirrorcle. The specific component is A8L2.2-5000AU-TINY48.4. The data sheet only includes VdifferenceMax and and frequency information, but ...
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What does ST mean with "Temperature Offset" for the temperature sensor in their IMUs?
When reading the datasheet of the LSM6DSO32 IMU I noticed on p. 29 the characteristics of the integrated temperature sensor (see screenshot below): The sensor gives a digital reading of 0 for a ...
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Pressure sensor without using MEMS chips [closed]
I'd like to figure out how to make a pressure sensor for very low cost (essentially disposable), mass produced piece of medical equipment.
The problem: this can't use any parts which aren't already ...
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Is it possible to set up multiple wake up interrupts on STM32. ? How to manage multiple sensor reading intervals?
I am new to developing applications on STM32 development boards.
Currently i have STM32 IoT discovery kit. I am able to configure all the sensors and read data. I am interested in low power design ...
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Considerations for transmitting the signal from a MEMS microphone over a short cable?
In my application I have the signals from 6 analog MEMS microphones (CUI Devices CMM-3729AT-42108-TR), each amplified by a pair of op-amps in a voltage follower -> inverting amp configuration. The ...
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How can I add (kHz to MHz) high voltage signal to a high voltage DC offset?
I am working with MEMS structures and need to move a device (switch) in a operating point with quite high offset. (150V DC offset and a voltage swing of 60V) To generate the high HF Voltage (up to ...
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Capacitance calculation of comb-drive actuator
I just want to make sure that I am performing this calculation correctly...
From this COMSOL study, I gathered the following info...
$$C_t = N\frac{\varepsilon_o\varepsilon_rl_ot}{d}$$
$$C_f = \...
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LSM303CTR 3-wire SPI and I2C - conceptual problem
I'm trying to interface LSM303CTR e-compass from ST-microelectronics with microcontroler. Due to design limitations I have to use 4-wire SPI.
This MEMS device has option to switch beetween 3-wire ...
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MEMS Oscillator not running, why?
For the latest iteration of my prototype, I replaced a quartz oscillator with (what I thought would be) a drop-in MEMS replacement: the DSC6013CI2A-033.0000.
It is suppling a 33 MHz clock to a TLC5955 ...
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Why are MEMS in QFN packages?
I've seen that many (if not all of them) MEMS, like accelerometers, they are only available in QFN packages.
Why is that?
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How is Gyro drift error related to error in velocity and position?
While reading about IMU on wikipedia I found this about its disadvantages:
"A constant error in attitude rate (gyro) results in a quadratic error in velocity and a cubic error growth in position."
...
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Frequency response of MEMS sensor in datasheet
I am looking for a MEMS acceleration sensor and the frequency range of 0 to 20 Hz is required. But after checking a lot of datasheets I am confused. Because in most datasheets I am unable to find any ...
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Invensense MPU9150 Accelerometer Raw Values Even
I've been working on pulling data from an MPU-9150 for a data filtering project, and I ran into a issue that I'm not sure of the cause.
When I set the accelerometer to ±2g or ±4g range, all the raw ...
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Signal conditioning for 2SMPP-03 Pressure sensor
I am wanting to develop a circuit that accurately measures 15 Omron 2SMPP-03 sensors within its full range of -50KPA to 50KPA. Could someone give me a head start or refer me to some information on how ...
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LSM303C temperature sensor
I'm trying to read the temperature sensor from the LSM303C. I have enabled the sensor and can see the values move when the temperature is changed. But, the format of the sensor data is not provided by ...
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Why the prevelance of mechanical oscillators in electronic circuits?
The clock sources in modern electronics seem to come invariably from quartz and MEMS oscillators, both of which generate vibrations mechanically. The amplitude and frequency of the vibration are ...
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Sampling DC and AC components of capacitive sensor
I'm using a MEMS capacitive pressure sensor SCB10H. As I understand it, I can wire it up in one of two ways. Either I can measure the absolute capacitance using a chip like the TI FDC1004. In this ...
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How do we extract the etchant after it is stopped at the boron layer in MEMs fabrication process?
Dopant-Selective etch stop method is where we create a layer of highly doped boron in the substrate to stop the etching process at that exact layer, but when that cavity is created the etchants are ...
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Replacement of MEMS gyroscope with better less noise devices [closed]
Is there any good replacement for MEMS based 6 or 9 degree of freedom gyroscope to use with Arduino ?
I read that most of MEMS are not reliable regarding the values, with slow reading and high noise ...
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How do we measure capacitance by change in vibration
A capacitively based MEMS affinity glucose sensor.
link to the IEEE paper, from where I've got this doubt.
The gold electrodes are separated with some distance and the permalloy is vibrating with ...
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Why does my smartphone level app require calibrating? [closed]
Doing some housework the other day I downloaded an app to my smartphone that included a level for measuring tilt. The app requires me to calibrate the level by first placing my phone on a perfectly ...
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