06 Electronics Design

redraw the echo hello-world board

Using EAGLE CAM tool, I redrew the ftdi hello echo board. First, I imported the components utilized in the board into the schematic and used "NET", "NAME", and "VALUE" to define connections between them.

add (at least) a button and LED (with current-limiting resistor)

I wanted to make a board in an arrangement of my mini submarine drawing so I uploaded a bitmap file and moved the board layout over it. The *move* option for eagle is pretty unintuitive: >select all using the *group* option. Then, select the move tool and right click on top of your layout. Then click *move group*

Since I was milliing the PCB out with the Modela, I exported the board as a PNG image at 600dpi in monochrome. Alternatively if I was to send this out to OshPark, I'd export it into a Gerber file instead. This Sparkfun tutorial details the process of running the CAM script and viewing it using: Gerber Viewer Online)

check the design rules, and make it

To begin milling, first the server needs to be started. Once that's up, load the settings into the FabModule. Following the selection options, I loaded the design, selected the endmill and zeroed the modela to my copper board. Finally, I select calculate to generate the tool path. Depending on how it looks, I might increase the number of offsets from 4 to 7-15 to get a cleaner finish on the leads.

I changed the endmill between from 1/64 for traces to 1/32 for interior.

After it finished milling, I cleaned out the copper residue with a razor blade and then picked it clean using tweezers before soldering all the components on.

extra credit: simulate its operation

Tools:

eagle > LTSpice? > modella mill > solder