Questions tagged [signal-processing]
the analysis, interpretation and manipulation of signals
967
questions
0
votes
1
answer
59
views
Why isn’t my overdrive circuit working?
I have attached an image of an overdrive circuit that I have designed for a guitar pedal. I have built the circuit and it isn’t working and I wanted to find out if there were any obvious design flaws/...
- 1
0
votes
1
answer
99
views
What is this 2-line communication protocol?
I tried a wide variety of protocol decoders in pulseview including UART, I2C, and SPI, but nothing seems to match. This is captured from communication between a topside controller and the mainboard ...
- 21
0
votes
1
answer
50
views
route on inner or outer layers for SPI clocks signals etc?
What is better for (for example) an SPI clock signal: to be routed on the inner layers (more ground, avoid EMC issue) or on the outer layer? (Avoid changing layers and impedance mismatch and any ...
- 1
0
votes
0
answers
33
views
Signal Function Analysis
I have attempted this problem but am unsure of what the solution should look like. I am confused specifically on the constants a and b, as well as the bounds of the function. I also do not understand ...
- 69
0
votes
2
answers
89
views
How to get the transfer function out of a Bode Curve on a datasheet?
I am trying to find the transfer function of AMC1350 out of its datasheet. I dont have any information about which degree of a lowpass filter or what kind it has. DC gain is 2/5. Cutoff frequency is ...
- 840
2
votes
1
answer
77
views
A low noise multiplexer
I am trying to make Faraday's cups array sensor, in which each signal coming from the cups must be amplified because it is too small (microampere or even lower).
But since I have too many cups, I need ...
- 73
0
votes
1
answer
55
views
Can Raspberry Pi be used for LVDS image signal reconstruction
I have a NOIP3SN5000A image sensor manufactured by Onsemi with a LVDS output. I would like to reconstruct the output signals into images by a Raspberry Pi 4B, can it work?
I have seen a lot of ...
- 1
0
votes
1
answer
59
views
Sketching fourier transform after sampling
I'm having trouble understanding how this system is supposed to work. My sketch (all my sketches are for fourier transforms) for \$X_b(jw)\$ are two pyramids centered at 7pi and -7pi with height 1/2. ...
- 159
0
votes
0
answers
70
views
Reverse engineering key fob RF signals
I have been trying to decode the signal of a keyfob with a cheap 315MHz RF receiver (XY-MK-5V) and a ...
- 121
0
votes
0
answers
54
views
How are PCM signals put onto a wire?
I just want to get a sense of how digital data is physically transmitted over cables using protocols like USB or Ethernet.
I've read that they use PAM signaling (USB4 uses PAM-3, Gigabit Ethernet uses ...
- 183
2
votes
2
answers
66
views
Is digital signal transmission different from square wave?
I am just getting into signal processing and am having trouble understanding where generating square-waves by means of harmonics is useful.
Digital signal transmission can be achieved by changing ...
- 183
0
votes
0
answers
28
views
ODE of LTI system
Given an LTI system and for an input \$x(t) = a\cdot tu(t)\$ while \$u(t)\$ is Heaviside function you know that the output is \$y(t) = (t^4+t^3)u(t)\$.
If not given that the system has ODE, how can I ...
0
votes
1
answer
48
views
How to make microcontroller such as Raspberry Pi external interruption handler for an antenna device? [closed]
I am pretty new to microcontroller, and I want to make wireless device, that actually consists of two devices:
One has a button, another has a led - when the button of the first device is pressed and ...
- 255
1
vote
0
answers
38
views
How do you find Image Rejection Ratio from doing FFT on ADC samples?
I'm trying to understand a particular code written by a former employee for measuring performance of an RX chain in a transceiver. I have to measure IRR(Image Rejection Ratio).
Certain input RF ...
- 21
0
votes
1
answer
50
views
Find the range of variables based on the steady-state response
I have a transfer function as below:
$$
G(s) = \dfrac{s(s+2)}{s^2+(b+2)s+ab}
$$
Now with input as
$$
u(t) = \sin{t}
$$
The maximum steady-state response of y(t) is less than 1, I would like to ...
- 203
5
votes
1
answer
122
views
How to reverse the behavior of a thermistor?
I have an NTC thermistor that reduces its resistance when temperature increases, but I need a circuit where resistance increases. Without using a different thermistor (or a microcontroller), is there ...
- 313
2
votes
1
answer
126
views
Sampling 24V one wire serial with a voltage divider?
I would like to sample 24V one wire serial with a voltage divider, wouldn't grounding the resistors in series potentially affect the data being transmitted?
I was considering using an optocoupler but ...
- 263
1
vote
1
answer
62
views
Transfer function of capacitor and resistor connected in series and one resistor connected in parallel with the capacitor
I have been trying to derive the transfer function H(s) of the circuit diagram.
I know how to derive CR circuit, but I'm stock on connecting another resistor with the capacitor. Can anyone help me ...
- 13
5
votes
0
answers
146
views
Why does my square wave signal from an Elegoo Uno R3 have 3V overshoot/undershoot?
I've just purchased my first oscilloscope, a Siglent SDS1202X-E, and am experiencing an issue with a square wave signal generated from an Elegoo Uno R3 board. I've calibrated the probes, and I'm quite ...
- 51
1
vote
1
answer
72
views
Determining the sampling rate / frequency from a graph
I don't understand how the two graphs in the image below are connected. The context is signal processing and sampling rate (+ its relation to bandwidth). I don't know the exact terms to look up. I am ...
0
votes
0
answers
55
views
How to properly take the discrete Fourier transform of a signal as well as calculate the power spectral density of the DFT?
I'm getting conflicting answers on how to properly represent a DFT and normalize the results as well as calculate the normalized PSD of the time series. For background, I typically work with voltage ...
- 1
0
votes
1
answer
80
views
How would you compute Fourier transform of a real world signal where the signal keeps getting updated (not a static one)?
A very naive question: How do we use Fourier transform for real world signals - for which you have the information only up to the present instant (and the present time keeps moving continuously)?
The ...
- 2,621
0
votes
1
answer
66
views
Filter output of a bandpass filter
The following question was asked in GATE 2014 S-1:
A 10 KHz even symmetric square wave passed through bandpass filter with centre frequency at 30 KHz and 3 dB passband of 6 kHz. The filter output is:
...
- 139
0
votes
2
answers
123
views
Zero crossing detector - MCU interrupt is delayed
I'm trying to catch zero crossing (using below circuit) when it exactly happened. Rising and falling edge intervals are not equal and they need 0.3-0.7 ms to reach corresponding logic level. Let say ...
- 55
0
votes
0
answers
93
views
INA219 current sensor with too much noise and impossibility of with filtering ESP32 + L298 H-bridge
Hey there 🤗
I have a project involving measuring a DC mini-motor, with a INA 219 sensor. The circuitry is as follows, where "Sensor de corrente" = Ina219 and the "Converter" = ...
0
votes
0
answers
39
views
Is it possible to simulate with some composition of signals an analog of a function of two variables and then to calculate its gradient?
With the help of an operational amplifier (op amp), a signal can be differentiated, using it in a differentiator mode. Due to that we can calculate an analog of a derivative of a mathematical function ...
- 101
0
votes
1
answer
44
views
Need help on signals and systems, Fourier representation of a signal
I've got a homework question for my signals and systems class.
In the question, we're given the graph of the magnitude and the phase of a continuous signal. Here are the graphs:
I have to find the ...
- 1
0
votes
2
answers
72
views
How to increase a mic output level?
I have an old lapel mic that outputs a signal that is way too small for most applications. In my attempts to learn electronics I started analyzing it and reading about the subjects. Still, I'm left ...
- 279
2
votes
0
answers
32
views
Effects of discretisation on bandwidth of low-pass filter
Consider a first order low-pass filter, with a cut-off frequency of (2π)*(8000). This filter will have a cut-off frequency at (2π)(8000), as well as a pole there.
$$
H(s) = \frac{1}{(\tau.s + 1)}
$$
...
0
votes
0
answers
27
views
AD7779 ADC Pin Mode Problem
I am trying to configure three seperate AD7779's to output continuously at pin mode operation (by using DOUTX pins, not SPI). However, even the decimation rate of 4095 is mentioned at the datasheet at ...
- 389
0
votes
1
answer
53
views
Magnitude of transfer function
I was able to find the transfer function of this LTI system block diagram, but am unsure of where to start on how to find the magnitude. The transfer function I have from this is:
$$H(s) = \frac{Y(s)}{...
- 1
0
votes
1
answer
91
views
Op-amp output is distorted after the second stage
For my following circuit, the input is sine wave. LA25P is a current sensor having a bandwidth of 200 kHz (-1dB). The R2-C5 low-pass filter is designed at 482 kHz.
However, if I have an input sine ...
- 1
4
votes
0
answers
137
views
LM311 comparator not working as expected
I am attempting to recreate the 'cheap SPAD' experiment detailed here, which uses reversed LEDs as Single-Photon Avalanche
Detectors. However I am running into a persistent issue when it comes to ...
- 63
0
votes
1
answer
71
views
What is the structure and type of harmonics generated by a very differentiated square wave (i.e bipolar spikes)?
this question is in two parts.
Firstly, can you please tell me what the structure and amplitude distribution is of harmonics generated by a differentiated square wave of 50% duty cycle, where the time ...
- 3
0
votes
1
answer
47
views
Get Motor RPMs from Resolver Signal
everyone.
I have a servo motor that outputs a resolver signal (sine, cosine, and reference). Each of the three signals is a differential pair (+A/-A, +B/-B, etc.). And the three signals are encoded ...
- 277
0
votes
0
answers
40
views
Transfer function h(t) of a positive feedback system
I want to find the transfer function h(t) of the below positive feedback system. I came out till this.
How can i get the inverse laplace of this function? say β = 1 and γ = 1.
- 19
1
vote
3
answers
71
views
Which lead is the output when 3 lead ECG system is used?
I am using ECG signal conditioning chip called AD8232. It takes 3 inputs, namely, right arm (RA), left arm (LA) and Right leg (RL) & gives one analog output as the ECG signal. According to ...
- 31
0
votes
0
answers
52
views
piecewise signal function
I have to construct an input signal to do integration and some operation on it on MATLAB,
this is my code, how to get rid of impulse shape?
...
0
votes
1
answer
32
views
Different accelerometer values for signal processing
I am trying to process accelerometer values. I found data sets from different accelerometer modules. Their output values are completely different. For example: I am collecting +-16g range 13-bits ...
- 3
0
votes
1
answer
146
views
Calculating inverse fourier transform and graphing it
Recently I stumbled upon Fourier transforms which means I am very new to it. I've been given a question from my professor to find the inverse Fourier transform of a frequency spectrum which is given ...
- 49
0
votes
0
answers
59
views
Type of memory used to design Arbitrary Waveform Generators (AWGs)
i am interested in understanding how the design decision is taken while choosing the type of memory to be used in AWGs. My understanding is that in most AWGs, waveforms are stored in a Digital memory ...
- 392
0
votes
1
answer
76
views
Need help with pulse sensor design modification [closed]
So I've got the below pulse sensor design. I don't understand why they filter before they amplify. I'd like to modify it in a way that I amplify the signal first, LPF second, HPF last. For some reason ...
- 492
2
votes
0
answers
309
views
Trying to perform transient frequency response with LTspice or Microcap, TL494 compensation
I have tried to do Bode plot of my uncompensated plant by myself in LTspice 17.1, but the result looks strange to me. This topic is a follow-on to this one.. I have no clue why it comes with 290 ...
- 111
0
votes
0
answers
45
views
Data-set creation and signal processing
I'm taking a digital signal processing course and I have a project to create a data set with a microcontroller and process it for this course. I want to count only dog bark for example not dog growl. ...
- 3
0
votes
3
answers
145
views
Can you explain this active filter?
I am trying to analyze the open source project OpenEEG's schematics. I came across a filter which supposedly has a 59 Hz cut-off frequency. I could not locate the 59 Hz pole of the filter. Can you ...
- 389
0
votes
1
answer
135
views
AC current limiter in a circuit
I have the following schematic of a circuit using an AD8652 op-amp.
I need to limit the output current to 5mA.
If the output current is more then it should reduce the voltage. Can someone suggest a ...
3
votes
1
answer
93
views
How to replace TCRT5000 IR sensor with TCRT1000 IR sensor
I've got a pulse sensing circuit based on the TCRT5000 IR sensor. Its working fine and I can easily see the pulse when finger is placed. But I tried replacing it with the TCRT1000 but there is ...
- 492
2
votes
2
answers
206
views
What is the true measurement duration for each sample made by a DAQ?
When a data acquisition system digitizer (DAQ,) or analog-to-digital converter (ADC) samples a continuous signal, how can one estimate the true measurement duration of the sampling action? By true ...
- 63
3
votes
0
answers
43
views
Cascaded discrete time system
I would like to propose my answers to the following exercise and you tell me if I am right or not.
Exercise:
We consider the cascaded LTI system of Figure 1:
Figure 1
And the impulsional response \$...
- 31
5
votes
2
answers
1k
views
Sampled 100 Hz sinusoidal signal from Hall sensor shows 10 Hz sidelobes when sampled at 500 Hz
I am working on a project where I need to measure an oscillating magnetic field that oscillates at a frequency of 100 Hz. For this reason, I am using a Hall sensor. I programmed the Hall sensor to ...
- 343