The Music Technology pack uses a single Sysblock and Flowcode Embedded to allow students to quickly construct a wide variety of digital music
applications and understand the principles of digital music manipulation and effects. Students will gain an appreciation of D/A conversion and
A/D conversion and Digital Signal Processing Techniques that allow music to be sampled, delayed, manipulated and produces in the digital domain.
Students make use of signal generators, microphones and speakers/headphones to create and understand a variety of applications in Music Technology.
The pack is suitable for students 16+ with an interest in embedded programming and Music.
Learning objectives/experiments:
Analogue to Digital Conversion
Digital to Analogue conversion
Simple Digital Signal Processing
Nyquist
Audio effects including echo, reverb, distortion
Mixers
Sampling and music creation
Delays and stadium balancing
EQ and filters
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Results
Simply connecting the input to the output allows students to study sampling techniques in digital audio systems. Varying the sample rate allows
students to understand the Nyquist criteria. Shown here are the simple data flow program and oscillograms for Nyquist compatible and incompatible
sample rates.
Nyquist result 1
Nyquist result 2
Nyquist result 3
Students can understand how digital audio signals are constructed and manipulated. In this case a mixer program allows students to mix together
different frequencies and waveforms to create musical chords and study their shape on an oscilloscope and their spectral plot. Shown here are the
waveforms for note A and chord A with spectral plot
Audio Mixer result 1
Audio Mixer result 2
Audio Mixer result 3
Audio Mixer result 4
Systems, Signals, DSP and FFT
The Systems, signals, DSP and FFT pack introduces students to a number concepts in digital systems including A/D and D/A conversion, Nyquist,
Digital Signal Processing, signal manipulation, Fourier analysis of signals and the FFT algorithm, and Digital Filters. Students perform a range
of experiments that teach them about the details of signal manipulation using a single Sysblock, pre- written programs created in Flowcode embedded,
a signal generator, an oscilloscope and a spectrum analyser. Students download the programs and carry out a number of experiments that teach them
about the parameters and techniques of Signal processing. There is also plenty of chance for creative programming using Flowcode embedded for the
advanced students who will find that the Sysblocks and Flowcode combination provide the perfect platform for the rapid creation of signal manipulation
systems.
Learning objectives/experiments:
Analogue to Digital Conversion
Digital to Analogue conversion
Nyquist
Digital Signal Processing techniques
Digital Signal manipulation
Convolution and level detection
Fourier analysis
FFT systems
Digital filters
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Results
This example shows how harmonics can be added to create a square wave. Images show the data flow diagram, a composite oscillogram with different
numbers of harmonics and a typical spectral plot.
Theory of Fourier example 1
Theory of Fourier example 2
Theory of Fourier example 3
Students can construct a wide range of different types of digital filter - including FIR and IIR types - and study their performance. The
images show the simple data flow program, and oscillograms and spectral plots of signals before and after filtering.
Digital Filters example 1
Digital Filters example 2
Digital Filters example 3
Digital Filters example 4
Communications and digital radio techniques
Once students have been through the Systems, signals, DSP and FFT pack they can move onto the Communications and digital radio techniques course.
This course allows students to construct and experiment on a wide range of systems based on Sysblocks. Students use a panel with three Sysblocks
on to create a sequence of communications modulators and encoders, add noise, and then demodulate / decode the resulting signals. In doing so
students understand the parameters of communications systems including Phase Locked Loop performance, signal to noise ratios, bit error rates and
the principles of digital radio techniques. The communications systems students investigate include PLLs, AM, FM, OOK, ASK, FSK, BPSK, QAM, QPSK
and DSSS. Students work with pre-written programs for Sysblocks. There is also plenty of chance for creative programming using Flowcode for the
advanced students who will find that the Sysblocks panel and Flowcode combination provide the perfect platform for experimentation with digital
comms. The hardware platform includes 3 x Sysblocks panels (encode/modulate, decode/ demodulate, and noise generator) and a mixer board.
Learning objectives/experiments:
AM and FM
Digital communications systems
Modulation / Demodulation
Encoders / Decoders
Phase Locked Loops
PRBS and Bit Error Rates
AM, FM, OOK, ASK, FSK, BPSK, QAM, QPSK and DSSS
Digital Radio Techniques
Spread spectrum techniques
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Results
The equipment allows students to set up AM and FM systems that show some of the principles of digital radio technology. Here you can see the
AM transmitter and receiver Flowcode data flow programs, an oscillogram of a 1kHz modulated wave and the associated spectral plot.
AM receiver transmitter example 1
AM receiver transmitter example 2
AM receiver transmitter example 3
AM receiver transmitter example 4
With the equipment it is possible to set up various kinds of modulator encoder - demodulator decoder systems. The first image here shows the
Data Flow program in Flowcode. Accompanying code sets up data packets. Also shown here are the I and Q outputs, constellation plots for 4-QAM
and 8-QPSK, an eye diagram for the system and the Bit Error Rate counter program.