The latest V3 PCBs arrived last week along with all my electronics (except two 39 ohm resistors I forgot to order). The latest design for the laser tag guns and PCB are pictured below.
The new board features the smallest components I could ever have imagined soldering by hand (and then smaller). Some of the pins are less than 200 microns wide! There are 4 QFNs and a LQFN package on the board and most everything else is at least 0603 or larger sized SMD chips. I tried using reflow soldering techniques to solder on the QFN packages but I couldn’t get the hang of it. It is a tricky art I will keep working to improve. So I went the ‘easier’ (most people would say harder) route of hand soldering each pin :) By the time I got to the 0603 components, they felt massive.
Of course, there were plenty of board mistakes that will be corrected in the V4 design (already ready for fabrication but awaiting potential software changes). Luckily nothing that will prevent the functioning of the board for prototyping.
This is a pleasant surprise. I had serious doubts as to my ability to solder QFN packages. On to the next hurdle! – Programming the SAM3X8C via USB bootloader…