© Armchair Applications, 2002
Pocket Oscillator is an audio signal processing tool for the Pocket PC 2002. A wide variety of audio signals can be generated and manipulated. An intuitive visual programming interface allows you to connect together any combination of the following modules:
Modules are first selected from a palette in the toolbar, and then positioned on the Pocket Oscillator canvas. Once positioned, the input and output connectors for the module can be dragged and dropped to other modules on the canvas, so connecting them.
As each Module is selected, a control panel appears which allows any variable parameters (e.g. frequency for the Oscillator Module) to be set. Also shown on some control panels (e.g. the Speaker) is the audio waveform present at the Module. Online help is available for each Module.
Modules on the canvas can be deleted (as can connections) by first selecting the Module with the stylus, and then clicking the Delete icon. In this version of Pocket Oscillator, a maximum of 20 Modules may be present on the canvas at any time.
Note: This version of Pocket Oscillator is a beta release. Users should be aware that Pocket Oscillator taxes the resources of the PocketPC, especially when the Microphone Module is used. Additionally, response times for activating Modules can sometimes stretch to several seconds. These issues will be addressed in the next release.
The Pocket Oscillator.exe file should be copied to the \Windows\Start Menu directory on your Pocket PC. Do not try to execute the .exe on your desktop PC: it wont work!
The following sections describe the various Pocket Oscillator Modules, and how they are used.
The left-hand screenshot shows a diagram being constructed in Pocket Oscillator. The highlighted Module (in red) is an Oscillator Module. A trackbar control allows the frequency to be adjusted between ranges that are determined by the setting of the radio button multiplier (x1, x10, x100 - in this example set to x10). The desired frequency can also be entered into the edit box (400Hz in this example). The phase of the signal can range from 0 to 360 degrees. (Two identical signals 180 degrees apart in phase, when added together, produce a signal of zero amplitude.) Finally, the type of waveform can be chosen from Sine, Square or Triangle. The online Help, shown in the right-hand screenshot, is available when the "Help" button is clicked, and describes the Module.
At the bottom of the screen is a toolbar with a set of icons representing the various Modules available. Clicking on an icon will add it to the diagram.Clicking on a Module in the diagram will highlight it: it may then be deleted by clicking on the Delete icon in the toolbar.
The screenshot shows a Microphone Module connected to an Adder Module. Sounds from the Microphone are shown in the upper part of display. Only one Microphone Module can be added to the diagram at a time!
The screenshot shows a Noise Module connected to the Adder Module. The Noise Module generates "White Noise". White Noise has a flat frequency spectrum, and sounds like a hiss.
The Adder Module sums two input signals together. In the upper half of the display you can see at the top the signal coming in to the Adder on the first input, then underneath the signal on the second input, and underneath that the resulting summed signal. You can sum any number of signals together by using multiple Adder Modules.
The Multiplier Module works in a similar way to the Adder Module, but multiplies rather than adds the signals.
The Volume Control is used to alter the amplitude of a signal. The slider control adjusts the amplitude between zero and two times the input signal's magnitude. Thus, when the slider is in the center, there is no amplification.
To exit Pocket Oscillator, click on the "Control" menu item on the toolbar, and then click on "Exit".
05/19/2003 J.J.Bunn Armchair Applications