User's Manual

3
Pin Network Name Type Explanation
1 GND Ground Ground
2 GPIO0 I/O
ES0 pin, pull down 1 second, serial 0 into AT
command mode ;Pull down ≥ 8 seconds, restore
factory default parameter settings
3 NC NC
4 UART_RXD1 I Serial port 1 receiving
5 UART_TXD1 O Serial port 1 sending
6 NC NC
7 NC NC
8 NC NC
9 NC NC
10 NC NC
11 NC NC
12 NC NC
13 NC NC
14 NC NC
15 NC NC
16 NC
17 NC NC
18 NC NC
19 NC NC
20 NC NC
21 NC NC
22 NC NC
23 NC NC
24 VCC_5V P External power supply pin 1: 5V @ 500mA
25 GND GND Ground
26 VDD_3V3 P
External power supply foot 2: 3.3V @ 500mA
External power pin: 3.3V @ 200mA