35 Cool DIY Gadgets You Can Make To Impress Your Friends

16. Joel the Joule Thief

instructables

17. Sawed-off USB Key

evilmadscientist

18. Micro BB Crossbow

dudeiwantthat

19. Make A Hologram With Your Smartphone

truebluemeandyou

20. Go Hands-Free with Alexa Voice Service and Raspberry Pi

makezine

21. Make Your Own 9V Battery-Powered USB Charger

apartmenttherapy

22. Build an Arduino-Powered Candy Vending Machine

makezine

23. Magic Mirror Hallway Dashboard

imgur

24. Submersible ROV

hackedgadgets

25. Easy DIY Heater

thegoodsurvivalist