Questions tagged [dsp]
DSP stands for Digital Signal Processing or Digital Signal Processor.
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Help using DSP48E and adding it into code
I'm trying to work on a school project, and we have to use DSP48E and I'm having some trouble using it. I've decided to use the MACC_MACRO inst: MACC_MACRO example given in VHDL.
My questions are:
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Digital Low Pass Filter and PWM Signal
I have a PWM signal going into an ADC.
After the ADC the signal is being filtered using an IIR single pole filter.
Performance is exactly what I want with one exception. The purpose of the filter is ...
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How to Switch DSP to Passive Speaker Driver?
I am working on an Active Noise Reduction project for a headset using Codec ADAU1772 from AD. There are two inputs, one of which is feedback mic. connected to AIN0, second is INT+ (Intercom or music) ...
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FPGA Ressource Estimation
Currently I'm planning my 'first' FPGA project.
I did some VHDL during university, but have no 'practical' experience yet.
Therefore, I'm having a hard time estimating the resources required before ...
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Eliminating noise from ADC readings using digital filters
I need to take some measurements using MCU internal ADC from the following circuit, to be able to calculate the amount of current produced from the programmable current source which discharging the C2 ...
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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)}{...
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DC offset to an ADC reduces dynamic range which reduces accuracy. How to quantify accuracy due to loss of dynamic range?
It’s understood that the dynamic range of the ADC should match the max amplitude of the signal to achieve maximum accuracy. If it doesn’t, you lose digital codes which reduces accuracy.
How can one ...
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SPI vs parallel data/address bus - speed and data troughput
I have a digital board (developed more than 10 years ago) which has a DSP and an FPGA that communicate over a parallel 16-bit data + 16-bit address interface. In the FPGA, there is a sort of dual-port ...
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Understanding how a digital microphone's output gets stored in DSP memory
I am working with a DSP that takes audio input from a digital microphone. For the sake of this discussion all input sounds are pure sinewaves.
The DSP receives microphone data as 24-bit numbers. Let's ...
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Splitting a mono line, instrument, or microphone audio signal for two consumers
I am building an audio device that receives a mono input signal from a microphone or instrument via a regular 6.3mm jack. From there it goes into a digital signal processor (a USB sound card, actually)...
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Why is the filter output not in sin form?
The lowpass filters I created with the Matlab fda tool are different from the sinus form in the simulation.
What could be the reason for this?
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Autocorrelation digital logic design
I'm trying to implement a autocorrelation module into my FPGA. I have been doing some research on the internet and there are some complicated and advanced methods that use a Fast Fourier Transform (...
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How would I draw a signal flow diagram for the transfer function of a resonant filter?
The transfer function is:
$$H(z)=\frac{(1-r)(1-rz^{-2})}{1-2r\cos(\omega T)z^{-1} + r^2z^{-2}}$$
I have started by finding the difference equation, but I don't know how to draw a signal flow diagram ...
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Repeated poles at origin: does this make system unstable, and why?
Let's say we have a control system that ends up having two poles at the origin. I've simulated this and it appears as though this takes the system into instability.
I just wanted to confirm, does ...
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Noise power v.s noise amplitude
I have started reading the following book: The scientist and Engineer guide to digital processing. At the beginning of chapter two, the following is said when talking about mean deviation v.s. ...
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Retrieving Transfer function from Block Diagram (Direct Form I or II) [closed]
I've done a few examples for the opposite of the asked question that is to make Direct Form I or II diagrams from the given Transfer Function H(Z). But when I try to backtrack and apply the same logic ...
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How is noise analysis done in practice
If we identify a signal as a Random Process how do we study it in practice, how to determine its characteristics such as stationarity(whether it is Stationary, Wide Sense Stationary or ergodic),how to ...
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Problem with SN7407 output
I'm carrying out an experiment using an SN7407, which is an open-collector output buffer.
The use of this IC is to make the pulses (PWM) coming from a DSP (~3.3 V) be sent to a gate-driver circuit (~...
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Way to transfer large amount of data between NIOS and FPGA
I'm searching a method to transfer large amount of data (350 bytes) from NIOS processor to FPGA via Avalon Interface. The board I'm using is DE0-Nano from Altera, therefore, I'm trying to implement ...
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GNU radio FRS transceiver
I am trying to implement the transmit section of this GNU Radio transceiver design, documented here.
This design is intended for a bladeRF SDR, but the hardware available to me is the USRP B210.
The ...
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Performing block reduction with many takeoff/summing points in sequence
I'm an audio programmer, and I've recently gotten into using transfer functions to model the response of my DSP. However, I've hit a roadblock in trying to reduce a block diagram of one of my DSP ...
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Noise reduction algorithm for an AC mains voltage measurement
I am measuring and displaying the mains voltage at six inputs with a 12-bit ADC. To make the calculation simple and fast I am only using 11 bits. I am sampling the 50 Hz sine wave at 20 points using a ...
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trace32 error "bus error generated by CPU"
I am trying to Boot a DSP TMS320F2812PGFA on his internal SARAM using trace32. The tool detects the processor and i can see it but when i try to run a script, where i initialize the clock and other ...
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Waveform acquired from scope, what is the sample rate for post processing?
I want to make a noise measurement with my scope, but I need it to be band-limited.
I am using a Tektronix TBS1102, which allows me to save to a USB flash drive an Excel/CSV file with the X and Y ...
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Matlab: using a small sample time for sine wave, makes the wave's frequency "accelerate"
I noticed that if I use a small sample time of DSP sine wave in matlab, the signal's frequency "accelerates":
This is the signal with a proper sample time:
But if I reduce the sample time ...
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How to modulate the amplitude of a square wave at high speed (MHz)?
I want to build a modulator for driving a laser. I want the laser to produce square pulses with varying amplitudes. Hence I built a 1 MHz square wave oscillator (relaxation oscillator with an opamp.) ...
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Digital signal processing vs. analog signal processing for a 100kHz DAQ project
I have a dumb question to ask (for a lot of you) but it has been bugging me for a while and I need someone who can give me a clear answer. (I'm a second-year in electrical engineering.)
I am working ...
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What does the circle with the “X” and the cross mean?
I am taking a look at a DSP block for a the Xilinx ZCU111 FPGA and I am getting held up on a simple question. I come from physics so I am not too used to looking at block diagrams yet, but what do the ...
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Interpolating a Discrete-Time High Pass Filter
I am currently working on a project on MATLAB, and I need to use interpolation and decimation on various low pass, band pass and high pass filters with sampling frequencies of 10kHz. There was no ...
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PCM5242 DAC: DSP Program and DSP Frequency for high sampling rates
I want to use a PCM5242 DAC (datasheet) in a project
The DAC has a built in DSP core that I don't want to use for anything custom.
The DSP can be programmed with custom code, or predefined codes in ...
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Signal Dimensions in Simulink
I'm using R2022a, in Simulink I can not find the Display tab to access Signals & Ports>Signal Dimensions. Could someone point me in the right direction please?. Also, in the figure below the ...
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Downconversion Intermodulation Frequencies - Where do they come from?
I recently came across this video which discusses the downconversion of a signal (referred to as IN) to an Intermediate Frequency (IF) using a Local Oscillator (LO). I'm assuming that all of these ...
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Why does a cosine function have a non-infinite Fourier coefficient?
I took my signals class a long time ago and have gotten used to using Fourier tables for a lot of things. I'm reading a textbook on communications and I stared at the Fourier transform equation for a ...
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How is a GPS receiver able to calculate SNR?
I know that there is a certain relation between bit error rate and SNR for every modulation scheme. But i wonder how a GPS receiver can measure bit error rate and how it able to calculate SNR (I could ...
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Is an antenna array with a tilted (rotated) antenna element always less optimal than a perfectly aligned antenna array?
Suppose I have a traditional linear antenna array. My element factor follows a cosine shape between 0-180 degrees. The relationship between my theoretical total antenna array pattern and the element ...
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How can the GPS position update rate be 10 Hz?
Based on stuff on the web (Wikipedia and others) the GPS navigation message bit rate is 50 bit/s. That includes all data needed for user position calculation (time, ephemeris, almanac, etc.) It seems ...
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Can phased-array (ULA) gain tapering effects be modelled using digital windows?
I am attempting to model the general behaviour of various tapering techniques. It seems applying gain tapering to a ULA has very similar effects to that of applying a digital window to a signal. In ...
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Tuning controllers in dual-loop control with feed-forward and decoupling signals
What would be the best step-by-step approach to tune PI controllers in a dual-loop control with decoupling and feed-forward signals?
I am trying to tune both the voltage and current controller in DSP ...
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Relative error of power estimation
I'm reading my teacher code for FFT windowing in Matlab and there is one thing I don't understand. When you run the code at the end it says:
...
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Why is Line coding called "Line coding"?
Why is line coding also called digital base band modulation named "line coding" where does it come? and how is the name it to modulation
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Multipath and antenna radiation pattern
Multipath causes fading in wireless communication systems.
Depending on the RMS delay spread vs the symbol period this fading can be frequency selective or flat
The question is does multipath in any ...
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Best way to output n digital signals using n-1 DAC channels
I have 3 digital signals that need to be mixed and output into the analog domain. My DAC has 2 channels (Left and Right).
The way I see it, I can:
mix the signals 1, 2, and 3 digitally and output ...
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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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DSP Fır filter speed
I've just started looking into DSP's. I have a few questions. We will apply Fir filter to the signal entering TMS320C6743. I want this filter to happen very fast. What does the speed of calculating ...
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ADC Input Frequency Bandwidth and Sampling Frequency
I want an ADC that samples at 3GS/s.
That means for a Nyquist converter - SAR ADC - I can sample signals at a maximum bandwidth of 1.5 GHz.
I want to sample signals from 0-40 GHz - which determines my ...
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Approximating a transfer function
Given the following transfer function:
$$H(s) = \frac{20ks + 1200k}{s^3 + 98s^2 + (20k - 191)s +900 + 1200k}$$
I'm asked to reduce this transfer function to a regular second order transfer function as ...
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How to measure the time it takes to receive a new sample from CODEC using a fixed sample rate of 48kHz?
in my current set up I have a CODEC set as master connected to my STM32F446RE (slave).
The current configuration utilizes I2S DMA interrupt callbacks to handle the input and processing of these ...
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What is the relationship between the number of bits and the sample rate?
Ok, so this topic keeps confusing me. I know that the number of bits is related to the vertical levels. The more bits, the more vertical levels we have. If we have a sample rate of 4 samples per ...
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Need to mix an audio signal from a low power device, into a high power speaker
Basically, I want to take a cable going from the car audio amplifier to a speaker which is sending around 50W of power, that cable, and put a mixer in there, where I will inject an audio signal that I ...
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Looking for a high-perfomance MCU for my thesis. The idea is to programme a digital processor that emulates tube amps in the best way possible [closed]
I've read papers that used the PSoC 5LP but the writers felt their hands tied by the limitations of the board. I wanted to step it up in the hardware department without busting a bank because the idea ...
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