5 5V | ATmega168 | 5V/3.3V~~~~
6 +-----+---|Vcc,AVCC PC4|---/--->iWRAP(RxD)
7 USB | C3 | PC5|<--/----iWRAP(TxD)
9 5V <--BATT + GND | | HHKB
11 D- <----+-----+--R2-----|INT1 PB2-4|------->ROW(6-8)
12 D+ <----|---+----R3-----|INT0 PC0-2|------->COL(9-11)
13 Z1 Z2 | PC3|------->ENABLE(12)
14 GND<----+---+-----------|GND PB0|<-------KEY(4)
17 GND+-C2--+--|XTAL1 RXD|------->Debug Console
18 X1 | TXD|<-------Debug Console
19 GND+-C3--+--|XTAL2 RST|---SW--+GND
28 SW: Push Switch(Optional)
29 BATT: Li-Po Battery, Battery Charger and Voltage Regulator(5V and 3.3V).