[dvh]

I noticed these boards always use LDO with 5.5Vin max, why not use higher value like HT7533 (30V), it's only $0.02 more expensive and you can use it with 9V battery or 12V battery, or 2 lithium in series, or hack, even 4 fresh AAA are over the 5V limit. The other extreme is using *1117 LDO which has massive dropout like 1.1V which makes it them impossible to use with single lithium battery.

[jpleger]

The really awesome thing about these being in simple reference designs, is how easy it is to swap out things like that. I really like how they have things laid out, and will be using this as a reference for jr. folks on how to lay out logical blocks in KiCad.

I have often thought how awesome it would be to have a bunch of proven / validated / supported open source blocks for common things like power supplies, sensors, etc. I think that at some point digikey or someone had a modular board that you could mix and match stuff into a reference design, but I can't remember the details.