Audio Oscillator

Generate sine, square, and sawtooth waveforms

• Library:

• Audio Toolbox / Sources

• 

Description

The Audio Oscillator block generates tunable waveforms. Typical uses include the generation of test signals for test benches, and the generation of control signals for audio effects. Parameters of the Audio Oscillator block specify the type of waveform generated.

Ports

Input

F — Frequency (Hz)

nonnegative scalar | vector of nonnegative values

Dependencies

To enable this port, select Specify frequency from input port for the Frequency (Hz) parameter.

Data Types: single | double

A — Amplitude

nonnegative scalar | vector of nonnegative values

Dependencies

To enable this port, select Specify amplitude from input port for the Amplitude parameter.

Data Types: single | double

DC — DC offset

scalar | vector

Dependencies

To enable this port, select Specify DC offset from input port for the DC offset parameter.

Data Types: single | double

Output

Port_1 — Output signal

vector

The Audio Oscillator block outputs a periodic signal defined by the parameters of the block.

Data Types: single | double

Parameters

If a parameter is listed as tunable, then you can change its value during simulation.

Signal type — Type of generated waveform

sine (default) | square | sawtooth

The waveforms are generated using the algorithms specified by the sin, square, and sawtooth functions.

Frequency (Hz) — Frequency of generated waveform

100 (default) | nonnegative scalar | vector of nonnegative values

• If Signal type is set to sine, specify Frequency (Hz) as a scalar or as a vector. If Frequency (Hz) is set to an N-element vector, then the output from the block is the single-channel sum of N sinusoids. If Frequency (Hz) is set to an N-element vector, then Amplitude, Phase offset, and DC offset must be scalars or N-element vectors.

• For square waveforms, specify Frequency (Hz) as a scalar.

• For sawtooth waveforms, specify Frequency (Hz) as a scalar.

To specify Frequency (Hz) from an input port, select Specify frequency from input port.

Tunable: Yes

Amplitude — Amplitude of generated waveform

1 (default) | nonnegative scalar | vector of nonnegative values

• If Signal type is set to sine, specify Amplitude as a scalar or as a vector. If Amplitude is set to an N-element vector, then the output from the block is the single-channel sum of N sinusoids. If Amplitude is set to an N-element vector, then Frequency (Hz), Phase offset, and DC offset must be scalars or N-element vectors.

• For square waveforms, specify Amplitude as a scalar.

• For sawtooth waveforms, specify Amplitude as a scalar.

To specify Amplitude from an input port, select Specify amplitude from input port.

Tunable: Yes

Phase offset — Normalized phase offset of generated waveform

0 (default) | scalar in the range [0, 1] | vector with values in the range [0, 1]

The phase offset range, [0,1], corresponds to a normalized 2π radians interval.

• If Signal type is set to sine, specify Phase offset as a scalar or as a vector. If Phase offset is set to an N-element vector, then the output from the block is the single-channel sum of N sinusoids. If Phase offset is set to an N-element vector, then Frequency (Hz), Amplitude, and DC offset must be scalars or N-element vectors.

• For square waveforms, specify Amplitude as a scalar.

• For sawtooth waveforms, specify Amplitude as a scalar.

DC offset — Value added to each element of generated waveform

0 (default) | scalar | vector

• If Signal type is set to sine, specify DC offset as a scalar or as a vector. If DC offset is set to an N-element vector, then the output from the block is the single-channel sum of N sinusoids. If DC offset is set to an N-element vector, then Frequency (Hz), Amplitude, and Phase offset must be scalars or N-element vectors.

• For square waveforms, specify Amplitude as a scalar.

• For sawtooth waveforms, specify Amplitude as a scalar.

To specify DC offset from an input port, select Specify DC offset from input port.

Tunable: Yes

Duty cycle — Square waveform duty cycle

0.5 (default) | scalar in the range [0, 1]

Square waveform duty cycle is the percentage of one period in which the waveform is above the median amplitude. A duty cycle value of 1 or 0 is equivalent to a DC signal.

Dependencies

To enable this parameter, set Signal type to square.

Width — Sawtooth width

1 (default) | scalar in the range [0, 1]

Sawtooth width determines the point in a sawtooth waveform period at which the maximum occurs.

Dependencies

To enable this property, set Signal type to sawtooth.

Samples per frame — Number of samples per frame

512 (default) | positive integer

Number of samples per frame, specified as a positive integer.

Sample rate (Hz) — Sample rate of generated waveform

44100 (default) | positive scalar

The sample rate must be greater than twice the value specified in Frequency (Hz).

Output data type — Data type of generated waveform

double (default) | single

Data type of generated waveform, specified as double or single.

Tunable: No

Simulate using — Specify type of simulation to run

Code generation (default) | Interpreted execution

• Code generation – Simulate the model using generated C code. The first time you run a simulation, Simulink^® generates C code for the block. The C code is reused for subsequent simulations, as long as the model does not change. This option requires additional startup time, but the speed of the subsequent simulations is comparable to Interpreted execution.

• Interpreted execution – Simulate model using the MATLAB^® interpreter. This option reduces startup time and the simulation has speed comparable to Code generation. In this mode, you can debug the source code of the block.

Model Examples

Generate Variable-Frequency Tones in Simulink

Examine the Audio Oscillator block in a Simulink® model and tune the parameters.

Block Characteristics

Data Types	double | single
Direct Feedthrough	no
Multidimensional Signals	no
Variable-Size Signals	no
Zero-Crossing Detection	no

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.