sinewave | time data acquisition , from Arduino to the web
kandi X-RAY | sinewave Summary
kandi X-RAY | sinewave Summary
Real-time data acquisition, from Arduino to the web: My speech at PyCon UK 2019 and PyCon X Italia 2019
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Top functions reviewed by kandi - BETA
- Handle incoming events
- Set the logger
- Loop over pubsub messages
- Return a redis connection
- Called when a channel is received
- Forward a websocket connection
- Print a trace message
- Connect to redis
- Handle websocket connection
- Close the websocket connection
- Receive messages from a channel
- Disconnect from the websocket
- Message received from websocket
- Receive a websocket message
- Receive a websocket
sinewave Key Features
sinewave Examples and Code Snippets
Community Discussions
Trending Discussions on sinewave
QUESTION
I am attempting to perform an FFT on a signal and use the resulting data to retrieve the original samples via an IFFT. I am using the CMSIS DSP library on an STM32 with a M3.
My issue is understanding the scaling that occurs with the FFT, and also how to get a correct IFFT. Currently the IFFT results in a similar wave as the input, but points are scaled anywhere between 120x-140x of the original. Is this simply the result of precision errors of q15? Am I too scale the IFFT results by 7 bits? My code is below
The documentation also mentions "For the RIFFT, the source buffer must at least have length fftLenReal + 2. The last two elements must be equal to what would be generated by the RFFT: (pSrc[0] - pSrc[1]) >> 1 and 0". What is this for? Applying these operations to FFT_SIZE2 - 2, and FFT_SIZE2 - 1 respectively did not change the results of the IFFT at all.
...ANSWER
Answered 2022-Mar-07 at 21:29As Cris pointed out some libraries skip the normalization process. CMSIS DSP is one of those libraries as it is intended to be fast. For CMSIS, depending on the FFT size you must left shift your data a certain amount to get back to the original range. In my case with a FFT size of 128 and also the magnitude calculation, it was 7 as I originally surmised.
QUESTION
I'm extruding a sine-wave curve into 3d but when rendering, I can see that the normals are not smoothed.
The sine-wave is generated with parametric normals, as follows:
...ANSWER
Answered 2021-Nov-14 at 02:32Stupid me. It was a small bug in the extruding method, which should be like:
QUESTION
I am looking for a way to set multiple dependent attributes in a class. Maybe this example further illustrates what I am trying to do. Currently I am solving this issue with multiple nested try statements. This does not seem the right way.
ANSWER
Answered 2021-Sep-15 at 08:20Given your logic, it must then be required that at least one of the arguments f and omega must be set, otherwise there should be a failure. You can assert this with the following statement:
QUESTION
After appending data to an empty array and verifying it's shape, I use tofile to save it. When I read it back with fromfile, the shape is much larger (4x).
...ANSWER
Answered 2021-Jul-10 at 17:38The problem is that rx_data has a float64 data type before you save it. This is because I and Q are float64 arrays, so when you use np.append, the type will be promoted to be compatible with the float64 values.
Also, populating an array using np.append is an anti-pattern in numpy. It's common to do in standard python, but with numpy, it is often better to create an array of the shape and data type you need, then to fill in the values in the for loop. This is better because you only need to create the array once. With np.append, you create a new copy every time you call it.
QUESTION
I have several questions on making a lowpass filter in python/scipy.signal. Would appreciate any answers.
- I'm trying to understand how
scipy.signal.lfilterworks. Does it take the filter coefficients and multiply them by the data values, so that fordata[500], it'll do
ANSWER
Answered 2021-Jan-24 at 19:04
- I'm trying to understand how scipy.signal.lfilter works.
scipy.signal.lfilter(b, a, x) implements "infinite impulse response" (IIR), aka "recursive", filtering, in which b and a represent the IIR filter and x is the input signal.
The b arg is an array of M+1 numerator (feedforward) filter coefficients, and a is an array of N+1 denominator (feedback) filter coefficients. Conventionally, a[0] = 1 (otherwise the filter can be normalized to make it so), so I'll assume a[0] = 1. The nth output sample y[n] is computed as
QUESTION
I am trying to FFT my complex signal and the output should be real. So I make this code
...ANSWER
Answered 2020-Nov-17 at 15:15At least this problem:
Code attempts to assign outside In[] range in 3 different loops
QUESTION
ANSWER
Answered 2020-Oct-10 at 22:01I totally followed this page and used Paint to measure necessary variables
QUESTION
I was trying to create a sinewave graph using Matplotlib for the parameters given as below.
Create a figure of size 12 inches in width, and 3 inches in height. Name it as fig.
Create an axis, associated with figure fig, using add_subplot. Name it as ax.
Create a numpy array t with 200 values between 0.0 and 2.0. Use the 'linspace' method to generate 200 values.
Create a numpy array v, such that v = np.sin(2.5np.pit).
Pass t and v as variables to plot function and draw a red line passing through the selected 200 points. Label the line as sin(t).
Label X-Axis as Time (seconds).
Label Y-Axis as Voltage (mV).
Set Title as Sine Wave.
Limit data on X-Axis from 0 to 2.
Limit data on Y-Axis from -1 to 1.
Mark major ticks on X-Axis at 0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, and 2.0.
Mark major ticks on Y-Axis at -1, 0, and 1.
Add a grid, whose linestyle is '--'.
Add a legend.
Wrote the below and it almost came as required, but the expected graph is slightly different to what i write. I did gave the x and y limits but the graph seems to be taking further than that.
...ANSWER
Answered 2020-Sep-25 at 12:31Your problem is with ticker.FixedFormatter. First, consider this solution:
QUESTION
I am trying to get a simple sinewave sound generation example working using SDL 2.0.12 on Windows 10, but no sound is being output. I have no idea if it is a problem with the code or with the output device or the audio drivers. I'd really appreciate suggestions of how I can debug the problem further.
...ANSWER
Answered 2020-Sep-23 at 09:13It turns out there were two things I needed to do to solve this problem.
For a float type the sound wave can only take values from -1 to 1, whilst I was using a much greater volume boost. I needed to change
QUESTION
I am trying to export pdf figures with the export_fig function, but it is cropping away the title. it is doing a nice cropping job at the other axis but not the north one. Anyone had this issue? My code is
...ANSWER
Answered 2020-Jul-18 at 21:39Solved this by upgrading to MATLAB 2020a and using function:
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You can use sinewave like any standard Python library. You will need to make sure that you have a development environment consisting of a Python distribution including header files, a compiler, pip, and git installed. Make sure that your pip, setuptools, and wheel are up to date. When using pip it is generally recommended to install packages in a virtual environment to avoid changes to the system.
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