BOM for ADE Arduino Mega Shield R1 - 33 ohm resistor (has only been tested with 1/2 watt 5%, but 1/4 watt will probably work) The 1/2 watt resistor is too big for the footprint, so you have to bend the wires funky. R2 - RES 1K OHM 1/4W 5% AXIAL DigiKey Part: CF14JT1K00 Q1 - TRANS PNP 40V 200MA TO92-3 DigiKey Part: 2N3906BU P1 - CONN HEADER VERT 3POS 2.54MM DigiKey Part: 61300311121 (goes on the bottom) P2 - CONN HEADER VERT 36POS 2.54MM DigiKey Part: 67996-236HLF (goes on the bottom) J2 - CONN MOD JACK 6P6C R/A UNSHLD DigiKey Part: TM5RU1-66(50) DFR02229 - MICROSD CARD MODULE FOR ARDUINO DigiKey Part: DFR0229