Specifications

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11
GPIO19
PWM7
SPI-MOSI
12
GPIO20
PWM0
SPI-MISO
13
VDD
14
GND
Note:
1. In default, UART2 (pin4 and pin5) are used for bypass communication and UART0 (pin6
and pin7) are used for output of debugging information and burning firmware. Please refer to the
description in DC Characteristics for UART output current level.
2. GPIO0 is the hardware function pin, avoid pulling up the two pins before powering on
3. GPIO0 and GPIO13 are pulled up at the same time. After the module is powered on, it
enters the burning mode
4.3. PCB Antenna
Please refer to Fig 2 for PCB antenna. Please avoid to place any electrical components,
wiring or grounding under PCB antenna area on main board and it’s better to leave this area
blank on PCB.