Part Substitutions

• Z8F0822, can be used in place of the Z8F0812
• HC-05 is optional. Also, the HC-06 should work with no changes to the layout or code
• Nearly any 3.3V low dropout regulator can be used
• Just about any phototransistor should work
• The same goes for the 3906, pick a PNP and adjust the base bias current

The board was laid out with toner transfer in mind. At the moment, the board will not fit in an Altoids tin. I may have to fix that, though using the tin might reduce the bluetooth interface's range just a bit. A more compact layout is also available, just send it off to OSH Park. This layout makes greater use of 0805(US) parts, but remains hand solderable.

The resistors can be most any type, and 5% would probably work just fine. As readily available as 1% resistors are, you might as well use them. However, size matters. Trying to place a 1206(US) part on a 0805(US) footprint is no fun.

All of the capactiors are tasked with filtering duty, so a +80/-20 type would serve. For the largest capacitors, I chose dry tantalum, instead of electrolytic, for their longevity.