COSC 4290 Embedded Systems

Spring 2014

Homework Assignment #2

Regardless what technology is, I like analog too.
-- Lou Gramm

Due: Wednesday, February 5th, 11:00am CST
Submit: Turn your C source file and an electrical schematic of your circuitry using the turnin command on the Systems Lab machines.
Expect to present a demonstration of your system during lab time.
Work is to be completed individually.

Analog Output

Configure your mbed to output one of four possible analog waveforms. Re-using the eight DIP switches from your previous assignment, two of the switches should select the waveform, and the other six should scale the period of your waves.

The four wave forms are:

• Sine Wave,
• Square Wave,
• Triangle Wave, and
• Sawtooth Wave.

Electronic Schematic

Use the gEDA schematic capture tool ("gschem") to capture an electrical schematic of your mbed and attached components for this assignment.

To import a pre-defined symbol for the mbed microncontroller:

• Create a directory to store your own component library,
• Download the mbed.sym file into that directory, and
• Create a new file in your home directory path ~/.gEDA/gafrc that contains the line (component-library "full path to your component library directory")

Restart gschem, and the new part should be available under a new library in the component menu.

Schematics should be submitted as PostScript or PDF prints.