# Questions tagged [sampling]

Periodical measurement of an electronical property of a system, most often voltage.

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### Input signal bandwidth of ADC

I prepare to use adc to do sub-sampling. Most SAR adc has -3dB input signal bandwidth in datasheet but no for delta-signam adc. Can I use modulation frequency as the bandwidth or there is another way ...
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### What's the sampling rate of STM32 series microcontrollers in kHz [duplicate]

I'm trying to find out the sampling rate of STM32 series microcontrollers in kHz
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### Effect on sampling time on BER

Just for some background context: A digital signal has jitter present on it. In this situation there is only random jitter (RJ), which is unbounded and normally distributed. When the digital signal ...
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### How to characterize an input signal?

I'm planning on doing some signal processing on my electric guitar with an MCU and I was wondering how I can characterize my input signal so I know if and what kind of pre-amp/ADC I'd need or if the ...
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### Convolution between bit stream sampled by N number of samples per bit with a channel modeled as low pass filter

I generated a bit stream in MATLAB, from the transmitter to be convoluted by the channel I use MATLAB function "randi" between 0 & 1, so it generates random vectors of 0s & 1s and ...
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### Calculating 3-phase real and apparent power using sampled signals

Using step-down/isolation transformers, I am sampling the phase-to-phase voltages of a 3-phase, 3-wire industrial utility system in the US (208Vrms, 60Hz). Additionally, I am sampling the line ...
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### Upsampling encoded bits (convolutional encoder) and downsampling decoded bits (Viterbi decoder)

I am testing the reaslisation of encoder and decoder. Initial parameters: BPSK. I start with BPSK sequence: ...
1 vote
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### How to minimize vTaskDelay in FreeRTOS?

I need to sample a signal with a sampling frequency in order to 2500 Hz. But, when i put any time in vTaskDelay(pdMS_TO_TICKS(time)) under 1 [ms], my programa start to bug. How can i fix this? Note: ...
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### Digital up conversion and digital down conversion

Description: I’m trying to use the standard sample rate of 61.44 MSPS on both sides of my digital transceiver(DUC and DDC,) so I’ll upsample my data from baseband data rate 3.84 MSPS to 61.44 MSPS ...
1 vote
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### Is it viable to use a Raspberry Pi with ADC to send, receive and process ultrasonic signals

I want to take a laptop-based ultrasonic radar system and convert it to a hand-held device. I have Tx and Rx filtering circuits already, now I need to decide on what to do the signal processing on. ...
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### How can a lidar achieve cm-level resolution?

In order to achieve cm-level resolution, it seems like a lidar would need to have extremely high sampling rates. Here's my thinking: Light travels at roughly 3·108 m/s, or 3·1010 cm/s. We need to ...
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### Frequency converter for spectrum analysis

I have an oscilloscope/spectrum analyzer that has a maximum sampling frequency of 20MHz and I would like to analyze the spectrum of a higher frequency band (also 20MHz wide) for example 90-110MHZ to ...
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### Sampling a continuous time signal in a DSP

We are tasked with sampling a continuous time signal in a DSP. Before sampling, the signal goes through an analog filter of which I know the continuous frequency function H(ω). I also know the Fourier ...
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### Sampling motion through travel

I have an object with an accelerometer on it that is going to travel rapidly for 14ms. My coworker says, "the bandwidth of this transient is 25Hz" .. "So we can sample at 100Hz to ...
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### What is a gated sampling technique?

This application note (page 1) metioned about "gated sampling techniques." I searched but found nothing except that one. Can anyone explain what it is? While naturally sampled peak and ...
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### ADC bit resolution (LSB) after a gain stage

If my signal path is as the following: My input DR is 20mVpp and goes through the above path, and the ADC used is 16 bits. Would the LSB be 5V/(2^16)=76uV or the gain will be added to the LSB as (5V/(...
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### Frequency domain analysis when sampling a switched (gated) integrator

I would like to use AC analysis (e.g. in spice) on a non-ideal op-amp integrator where the reset switch is open, and then apply a shaping function to the result of the AC simulation (in the frequency ...
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### Sampling ±50 V signal with differential ADC [closed]

I am looking to use a differential ADC to sample a ±50 V signal with this ADC here (AD9238). What are some ways to bump the signal down to a level the ADC can read? Signals would be sampled at >= ...
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### Magnitude error in switched capacitor circuits

I am currently working with switched capacitor circuits used as sample and hold stages, gain stages, and integrators. It is obvious that switching capacitors to simulate resistors involves sampling of ...
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### Smaller sample rate of a non symetrical wave

I need to sample a digital waveform and the shortest period I found was 6.9us. But at given point of communication there is a very short pulse of 2.116us and a long period of inactivity. So, I ...
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### Minimum sampling duration of beats

Let's take the signal to be sampled to be made up of several sine waves close to one another in frequency, e.g. 1MHz, 1.001MHz, 1.002MHz,... 1.005MHz I assume in the time domain we would see beats 1ms ...
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### What is the difference between sampling time and sampling interval and sampling rate?

I understand that ADC sampling time is the ADC clock cycles for which the sample and hold capacitor is charged up to the channel input voltage. This is a configurable parameter and its value ranges ...
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### When these prototype devices become commercialised/productionised, how is the signal processing aspect of the oscilloscope built in to the device? [closed]

I read a lot of research papers that use large and expensive equipment, such as oscilloscopes, to do their signal processing. Oscilloscopes offer high sampling rate and bandwidth, which makes them ...
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### What is this Digilent Analog Discovery device doing in this experiment?

I'm a novice to electronics, and I was wondering if someone would clarify an experiment I just witnessed. A photodiode was set up to receive some signal. This signal is then read by a transimpedance ...
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### How can you transmit 10 Gbit/s using a 250 MHz carrier frequency (Cat 6 Ethernet < 55m)?

I refer to this cable because they also include a test certificate (3rd icon down on left). The cable is tested to 236.5 MHz (250 MHz nominal). Yet it's a Cat 6 cable capable of 10 Gbit/s (if length &...
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### What should be my sampling frequency for a peak detector output where it is extremely important for me to capture the first time the peak occured?

Following is the output of the peak detector: The amplitude is not important to me, however the time when the peak occurs is extremely important. So my microcontroller will have an algorithm like ...
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### Methods to measure output variable in a feedback system

$R(t)$ is reference signal, $U$ is controlled input, $Y$ is output of the plant, Ts=1 s is sampling time (i.e. after each 1 sec output and reference is compared) and input output relation of the ...
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### AC voltage measurement sampling

I do micro-controller programming, but I'm not very good in electronics. I'm trying to read some circuits to understand what I'm building. Through that I came across the attached circuit. I couldn't ...
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### OFDM IDFT implementation

i have some doubts with the implementation of the IDFT in OFDM systems. The question concerns the expression of the IDFT of the OFDM signal. During the symbols period $T_s$ we have the following ...
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### Finite-duration signal in the time domain, means what exactly in the frequency domain?

I'm trying to understand exactly what restrictions a finite duration time domain signal has on its Fourier transform. I found a helpful table in The Fourier Transform and its Applications by Ronald ...
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### I use the NUCLEO-L476RG board. ADC runs at 64 MHz and ADC has a 5.33 Msps maximum conversion rate with full resolution

I need to take 10 samples (10 Hz) per second. How can I set ADC configurations on CubeMX. I use the lowest sampling time (2.5 cycles), but the values I convert and use in ADC change very quickly. ...
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### What happens if the signal frequency exceeds the sampling rate?

As the title states, I was wondering what happens to the frequency contents of the sampled signal of a pure sinusoidal signal that exceeds the sampling rate. I am familiar with the shannon theorem and ...
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### Time uncertainty of an ADC sample for a given sampling frequency

I am working on a project which involves time difference of arrival calculations. I need to calculate the uncertainty of my timing measurements. I am using an ADC to sample the signals who's times of ...
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### STM32 ADC sampling with timer and DMA and send data to computer with USB

I want to sample a 4kHz signal that is produced by a signal generator. I read 2000 samples in a row and then I send it to computer via virtual serial that is provided by USB of STM32F103C8T6. I set ...
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### is using both Nyquist's and Shannon's Theorem possible?

For instance, say I have a cable bandwidth of 1 MHz, and a signal-to-noise ratio of 255, how would I calculate the maximum bit rate possible if I were to be transmitting data via this cable using 4 ...
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### Simple low pass digital filter implementation for non-uniform sampling?

I have a system sampling an analog input and I want to filter that value using a simple, first order filter. EG something of the form: Yn = A*Xn + B*Yn-1 However I have no control over the ...
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### Reliability of Sampling Rate vs Absolute Timestamps

I am building a system with multiple sensors and I want to sample the different sensors at different rates. For the sake of an example, I am using two MAX30102EFD-T sensors. One of the sensors I want ...
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### K-path sampling transfer function

I'm trying to derive the overall Z-transform for the K-path sampling system shown below from Baker's CMOS Mixed-Signal Circuit Design. I numbered some of the equations that I'll reference. The full ...
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### Types of sampling and signal processing: some conceptual questions

I'm studying signal processing and right now I'm going through types of sampling and how they apply, advantages and disadvantages. I have some questions about these concepts that I would like to ...
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### Signal sampling at different points in a signals path without degrading the signal?

I am passing signals through an organic substrate & recording the response at different locations via differential probes that feed into my DAQ a Pico 24. See diagram below for set up. The ...
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I want to sample a signal at 44kHz. I've tried to set up the ADC with DMA and calculated the conversion time so that I get that 44kHz sampling frequency. My thinking is that with continuous mode ADC, ...
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### Shannon-Nyquist - only for repeating signals?

This was triggered by the comments in this question. I'm using this definition of the Shannon-Nyquist theorem (form wikipedia): If a function x(t) contains no frequencies higher than B hertz, it is ...
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### Calculating DAC samling rate from datasheet

I want to use the DAC121S101 DAC (attached) and was wondering if my sample rate calculations are correct. Settling time is 10uS which means max sampling rate would be 1/10us= 100KHz, 100KSps But need ...
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### Exercise relating to FIR filter [closed]

I was trying to resolve a problem from "Understanding Digital Signal Processing". I have some questions about it. Why do we need to redesign the filter if we find out that the sample rate is ...
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### ADS1115 differential measurements - resolution limited to 12 bits instead of 16 bits

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I am working on an Arduino board and I have no previous experience with it, unfortunately. I need to sense the voltage signal from a sensor using the ADC of the Arduino. I have an Arduino Due manual ...
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### What are the different types of digital signals

In a digital logic class I was taught that a digital signal is one whose y-component, voltage, is discretized but whose time domain is continuous. In a signal processing class, we worked with digital ...
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### Switched capacitor sample and hold circuit as as mixer

I am trying to find out how important the "hold " level in a sample and hold down-conversion mixer is. If the level is decreased, will it lead to any loss? Out of these three subfigures, ...
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### What is the "input" being fed into a Delta-Sigma Modulator in a Fractional-N PLL? Are bits needed for a specific resolution at the input or output?

I'm doing some reading into Fractional-N PLL design and I have a bit of conceptual confusion regarding a delta-sigma modulator used to toggle the modulus of a divider. If you're trying for a certain ...
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