I only soldered the basics into these. Given that most projects won’t need all the extras (Usb, Lipo, reset button, some of the passives), I can make some really cheap boards by only using what I need. I’ll still use fully populated boards that I’ve built or bought for prototyping, but I’ll be able to stick <$10 sensors everywhere as well.
The one on the left is my AtMega328 + RS485 interface. The one on the right is the Adafruit Huzzah board.