This desktop speaker turned out well, and I asked Jack at Prime Images Photography to take some real product photos. There's lots of interesting stuff here, including the volume knob's state machine and some handy prototyping tools from Mikroe. I'll get into these in some later posts.

I've been working on a PCB for a small loudspeaker project called Amey. I showed a rendering of the bare PCB a few weeks before I sent the design to Slingshot Assembly in Denver. I got the assembled PCBs today:

They installed the snap-in standoffs at each corner on the component side, which helps to protect the other components during shipping. That was a nice touch.

Update -- oops, the ADC doesn't have a clock

I made a showstopper mistake with the rev A boards -- I didn't provide a clock to the I2S ADC. The PCM1802 ADC from TI can be an I2S master, but it has no way of generating its own timebase. The fix is to figure out how to get a clock to the PCM1802. I made a second PCB to hold the DSC60xx 16.9344 MHz oscillator and its bypass capacitor. You can see the second PCB below.

I carefully wired up the little PCB, and now I see the correct clocks:

I name my PCB projects after lakes in Wisconsin, and this one is named Afterglow. I used PCB to create the rendering shown below.

I'm excited to be using SlingShot Assembly to fabricate and assemble these boards.

I use PCB to design PCBs, and I recently needed to embed a list of drills and their uses in a plain text file. PCB's drill file looks like this:

M48
INCH
T72C0.010
T71C0.015
T70C0.067
T69C0.039
T68C0.030
T67C0.046
T66C0.138
%
T72
X010249Y009035
X010249Y005886
X010268Y008256
X010268Y007075
X010268Y005107

...and I wrote drilltable.tcl to generate tables like this:

|------------+----------------------+------------|
| Tool       | Hole size (inch)     | Count      | 
|------------+----------------------+------------|
| T72        | 0.010                | 218        | 
| T71        | 0.015                | 95         | 
| T68        | 0.030                | 3          | 
| T69        | 0.039                | 10         | 
| T67        | 0.046                | 15         | 
| T70        | 0.067                | 1          | 
| T66        | 0.138                | 4          | 
|------------+----------------------+------------|

This borrows from an excellent usage example of Tcl's format command at the Tclers Wiki.