No updates for quite awhile, but it seems appropriate now as considerable progress has been made.

The following details the (hopefully) near-final implementation of the DAC/microcontroller interface.

first, the connection of only 6 data bits (will be using at least 8), in order to test the new DAC's functionality:

First, an image of the messy testing setup I am using (courtesy of UCI's MSTB 222 lab):



Next, a detail of the microcontroller/DAC connections. Note that I am only using the 6 most significant bits for transfer to the up-to 12-bit DAC. It's only because my connections didn't fit together, this will be resolved soon. Here's the picture:



Third, this is an image of what a low resolution, 1000Hz sine wave looks like when displayed on a digital oscilloscope. I would say here that a picture is worth only a few words, but the output from the speaker was music to my ears. Again, here's the picture:



and finally, a video of the microcontroller/DAC combo in action. As the youtube details state, the output from the connected speaker is pretty hard to hear due to the digital camera's microphone capabilities. The noise in the background of the video, which appears as more of a buzzing background noise, is actually a 6000Hz sample rate, 8-bit/sample 1KHz pure sine wave being played through the speaker, based on a .wav file generated by the NCH Tone Generator (a demo program I'm currently using). Here's the video, all 9 seconds of it: