Tuesday, April 3, 2018

OFBC 2.0

For Toxic BBQ 13 (DEFCON 25), we returned to the OFBC to see if we could improve the design and add some needed table decorations to Toxic BBQ.

The first step was to simplify the PCB creation. I created a new layout in Fritzing that reduced whitespace. It also moved off-board components like batteries and the LED modules to use JST connectors for easy installation and swapping.

Next, we redesigned the case. Instead of a three piece design requiring glue to assemble, the two pieces would be a base and a lid with a logo. Everything could be screwed into designed posts and covered with the lid. It was a snap.

Production was much smoother, but it had some hiccups that prevented us from delivering to the barbecue. Sparkfun supplied much the same components for about 15 bucks per. OSH Park did a great job with the PCBs. I was able to directly convert the Fritzing designs to printable format. Each board was less than 2 bucks by the time we finished. Never again will I make my own PCBs by hand. Shapeways took care of the cases for us. The prototyping went well and matched the designs, but the mass printings were so delayed that they didn't arrive in time for the barbecue even with expedited shipping. The resin product looked much better than the filament-printed 1.0 model. The cost at 20 bucks or so each was not prohibitive, but it certainly wasn't mass-market ready.

BoM at Sparkfun
PCB at OSH Park
Case at Shapeways

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