CSCI 255 — Amplification

Starting points

Controlling power

Melody_PIC32.X.tar.gzThere have been two times this semester where we approached the analog world.

This week let’s try to make the experience a bit more powerful. Melody_PIC32.X.tar.gzWith the parts we have available, there are a few ways to accomplish this.

Be aware that you must use an external power source on the controlled device. Trying to power loud speakers or motors from your computer would just result in the on-chip voltage level getting too low.

More volume

There are at least two ways you could get a louder sound.

The first is using a one-transistor amplifier. You can read about this at One transistor audio amplifier for Arduino projects at previous CSCI 255 lab.

The second is using an op amp. You can read about this at Op Amp basics. In a past CSCI 255 lab, we’ve had pretty good luck using the op amp application found in the upper-left corner of page 5 of the LM386 data sheet with a 3G Ω human resistor.
off    on

Controlled movement

OK. You really might be able to get away with driving a small speaker directory from you micrcontroller (after all we’ve already done that in lab once), but you could never do that will a motor.

You can use the one transistor solution of Arduino lesson 13. DC Motors. Alternatively, you could use a Arduino Motor Shield or explore the wide range of solutions found on the the University of Minnesota ME2011 web site. By the way, we controlled a few Big Lots bird in the class of 2012.