Schematic
R305
2K7
R304
1K5
PWR_FLAG
PWR_FLAG
TX
RX
USBVCC
/ERASE_CMD
/MASTER−RESET
USBVCCU2
USBVCCU2
ATMEGA16U2 is running at 5V
16U2_RX
16U2_TX
USB Boot Enable
RXL
TXL
+5V
R308
1K
R309
1K
A
K
D303
YELLOW
A
K
D302
YELLOW
R310
10K
R307
1K
RESET_CMD
R306
1K
RD+
RD−
R302
22R
R301
22R
Z302
PGB1010603
Z301
PGB1010603
C301
100nF
1
2
F301
500mA PTC 1812
USB
VCC
1
D−
2
D+
3
ID
4
GND
5
MNT
MNT
P301
RD+
RD−
C305
1uF
C302
100nF
+5V
C304
22pF
C303
22pF
SCK
MOSI
MISO
D301
CD1206−S
+5V
R303
10K
MOSI
RESET
SCK
MISO
1
2
3
4
5
6
ICSP301
M02X03
XTAL1
1
XTAL2(PC0)
2
GND
3
VCC
4
(AIN2/PCINT11)PC2
5
(OC0B/INT0)PD0
6
(AIN0/INT1)PD1
7
(RXD1/AIN1/INT2)PD2
8
(TXD1/INT3)PD3
9
(INT5/AIN3)PD4
10
(PCINT6)PB6
20
D−
30
(XCK/AIN4/PCINT12)PD5
11
(OC0A/OC1C/PCINT7)PB7
21
UVCC
31
(RTS/AIN5/INT6)PD6
12
(INT4/ICP1/CLK0)PC7
22
AVCC
32
(CTS/HWB/AIN6/TO/INT7)PD7
13
(OC1A/PCINT8)PC6
23
(SS/PCINT0)PB0
14
nRESET(PC1/DW)
24
(SCLK/PCINT1)PB1
15
(PCINT9/OC1B)PC5
25
(PDI/MOSI/PCINT2)PB2
16
(PCINT10)PC4
26
(PDO/MISO/PCINT3)PB3
17
UCAP
27
(T1/PCINT4)PB4
18
UGND
28
(PCINT5)PB5
19
D+
29
PAD
PAD
IC301
ATMEGA16U2
XTAL1
XTAL2
RD−_CONN
RD+_CONN
USBVCCU2_CONN
X301
TXC 7A 16MHz 18pF