ambient solarcell

  * http://www.digikey.com/product-detail/en/AM-1454CA/869-1001-ND/2165186
  * from: https://github.com/mossmann/fireflycap solarcell로 모아서 netscap 3f 수퍼캡으로 저장.
  * http://www.kickstarter.com/projects/mossmann/firefly-cap
  * https://github.com/mossmann/fireflycap/blob/master/doc/fireflycap-schematic.pdf

Bettery Free
 
  * http://www.powercastco.com/products/powerharvester-receivers RF받아서 DC 5.5v 만듬.
  * http://wisp5.wikispaces.com/WISP+Home rf로 받아서. S-882Zxx로 안정화하고 LDO(TPS780270200DDCT)로 전원 레귤레이션