Specifications

13
GND
GND
GND
14
GND
GND
GND
15
BAT
Power
Power
16
P25
Digital I/O
General purpose IO
17
P00
Digital I/O
GPIO0/UART1_TXD
18
P01
Digital I/O
GPIO1/UART1_RXD
19
P02
Digital I/O
General purpose IO/I2_SCL
20
P03
Digital I/O
General purpose IO/I2_SDA/JTAG_NTRST
21
P04
Digital I/O
General purpose IO/SPI_SCK/JTAG_TDI
22
P05
Digital I/O
General purpose IO/SPI_MOSI/ JTAG_TD0
23
P06
Digital I/O
General purpose IO / SPI_MISO/ JTAG_TCK
24
P07
Digital I/O
General purpose IO / SPI_NSS/ JTAG_TMS
9.Design notes：
In order to better SNR, please pay attention to the hardware design of
PA, DC booster, DC/DC circuit and the module power circuit to avoid
influencing module.
10.Note：
A．The signal strength is depending on the environment of Bluetooth
application, such as wood and metal will block the transmission signal to
get the shorter transmission distance.
B．Because of metal will block the signal transmission, it is recommend
not to using the metal housing.
C．PCB layout guideline: no any copper existed in the antenna area of the
module is the PCB antenna, the metal will weaken the function of the
antenna when the antenna module to the module board, following
prohibited paving and walk the line.
D. If the module antenna next to the battery、 metal, liquid crystal screen, loudspeaker,
at least keep them away from antenna distance 15mm
E. When layout the power supply line recommended star line, and to ensure that the
Bluetooth module Power supply lines is better , and BT should be with the amplifier,
power amplifier, MCU, separately, and the underside of the BT has no other
interference.