Schematic

v10
USB to Serial
3.3V Regulation
Buffer for RX LED
GND
GND
CH340G
GND
10pF
10pF
12MHz
microB
GND
GND
AP2112-3.3V
1.0uF 1.0uF
GND GND
5V
5V
10nF
GND
3.3V
1K
0.1uF
VCC
5V 3.3V
GND
VCC
VCC
330
VCC
GND
VCC
Default 3.3V
Move jumper to 5V
for 5V VCC and Logic
Serial Connection
U2
GND
1
TXD
2
RXD
3
V3
4
UD+
5
UD-
6
XI
7
XO
8
CTS
9
DSR
10
RI
11
DCD
12
DTR
13
RTS
14
R232
15
VCC
16
C4
C5
Y2
D+
D-
VBUS
GND
ID
SHIELD1*3
J1
U1
IN
GND
OUT
EN
NC
C1 C2
C6
R2
C3
J2
1
2
3
4
5
6
JP1
R3
B
2
A
1
Y
4
53
CTS
CTS
DTR
DTR
TXO
TXO
RXI
RXI
RXI
SHLD
N. Seidle
Released under the Creative Commons
Attribution Share-Alike 4.0 License
https://creativecommons.org/licenses/by-sa/4.0/
Design by:
USB B