Merge pull request #1 from penguinscontrol/master

Tutorial 2 sketches
Merge pull request #1 from penguinscontrol/master

sync repos
Tutorial03

Tutorial3(aka 6)
Merge pull request #2 from penguinscontrol/master

Tutorial 4
Merge pull request #3 from dpiao92/master

Tutorial 3
Merge pull request #1 from frankguolee/master

Sync