The sine wave is generated using the sin function in MATLAB. The start and finish variables mark the start and finish indices of each frame. If enough data is cached, read from the buffer and perform the FFT. View the FFT on an array plot.
start = 1;
for Iter = 1 : 2000
numToWrite = randi([200,800]);
finish = start + numToWrite;
inputData = sin(start:finish)';
start = finish + 1;
write(asynBuff,inputData);
while asynBuff.NumUnreadSamples >= 256
x = read(asynBuff,256);
X = abs(fftObj(x));
plotter(log(X));
endend
Data written to the buffer, specified as a vector or a matrix. The maximum number of
rows in the buffer is determined by the Capacity property of
asyncBuff. The number of channels in the buffer is determined by
the second dimension of the first data written to the buffer. Successive data inputs can
vary in the number of rows, but the number of channels must remain fixed. To change the
number of channels, you must call release on the buffer.
For example, the following is accepted:
asyncBuff = dsp.AsyncBuffer;
% First call to write
write(asyncBuff,randn(15,5));
% Add more data with a different number of rows
write(asyncBuff,randn(25,5));
write(asyncBuff,randn(5,5));
The following is not accepted and errors out:
asyncBuff = dsp.AsyncBuffer;
% First call to write
write(asyncBuff,randn(15,5));
% Add more data with a different number of columns
write(asyncBuff,randn(15,15));
To change the number of channels, call release on the
buffer.
asyncBuff = dsp.AsyncBuffer;
% First call to write
write(asyncBuff,randn(15,5));
release(asyncBuff)
% Add more data with a different number of columns
write(asyncBuff,randn(15,15));
Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical Complex Number Support: Yes
Number of samples overrun in the current call to write. The number of samples overrun is the number of unread samples
overwritten. If x is a multichannel input, then
nOverrun is the number of rows of data overrun.
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