UART 2 (Inside Casing)

Pin
Signal
Voltage
1(red)
VCC
Power 5V
2
RX2 (in)
TTL 3.3V
3
TX2 (out)
TTL 3.3V
4
EXTINT
TTL3.3V
5
PPS
3.3V
6
GND
GND

USB Port (Inside Casing)

Pin
Signal
Voltage
1(red)
USB_5V
Power 5V
2
D-
TTL 3.3V
3
D+
TTL 3.3V
4
GND
GND
5
GND
GND