WithStrings Audio Generator

A basic audio generator: adjust shape, frequency, and amplitude.

AudioGenerator streams data to the audio output (music stream) of an Android device using the user selected function, frequency, and amplitude. Wave-forms available are sine, square, and noise. Frequency is selected with multiplier buttons and sliders. Audio output amplitude can be adjusted from 0-100% with the amplitude slider. A numeric readout doubles as a play/pause button. It shows frequency, period, and nearest musical note (based on A=440Hz) for sine and square signals (noise contains an assortment of frequencies).
Instructions

Launch the AudioGenerator application. The initial settings are for a sine wave at 440Hz with a 50% amplitude. The Play/Pause button can be pressed and a 440Hz tone will be generated. Pressing the Play/Pause button again will stop the output. Playing or paused, any slider or button can be adjusted to change the frequency, waveform, or amplitude. Note that audio outputs are AC coupled. The output creates a network with external devices such as ear-buds or amplifiers. The interaction with the devices and internal coupling is evident when a square wave
is selected.

Characteristics
Operating System: Android: Minimum API 9, Gingerbread
Permissions: None
Audio Output Rate: 44100 samples per second
Audio Mode: Monophonic
Frequency Accuracy: 0.1 Hz
Output Amplitude: (Amplitude slider 100%) 35mv pp @10Hz sine, 700mv pp @10Khz sine
These are device and terminating circuit dependent.
Settings:
Frequency - Sine10Hz to 20KHz
Frequency - Square 20 Hz to 2Khz
Functions: Sine, Square, Nose
Amplitude: 0 to 100% on Music Stream
Play/Pause
Note Display Range: C = 16.4Hz to B = 7902Hz
Devices Tested: HTC Incredible 2, Google Nexus 7 (2013)
Identity: sin(u)sin(v) = 1/2[sin(u-v) + sin(u+v)]
Graphics Design: N. Dynamite

AudioGenerator Manual http://www.withstrings.com/withstrings_audiogen_manual.pdf