Data Sheet

-
13 -
No. of
module
pins
No. of
QFN32
p
ackage
pins
Pin signal Direc
tion
Pin specifica
tion
8 31 PD1
I/O
GPIO
9 30 PD2
I/O
GPIO
10 21 PA4
I/O
GPIO
1
1
20 PA3
I/O
GPIO
12 17 PA0
I/O
GPIO
13 15 PB1
I/O
GPIO
14 5 PC4
I/O
GPIO
15 18 PA1
IO GPIO;
SWCLK
16 6
PC5 IO
GPIO
17 19 PA2
IO GPIO; SWDI
O
18
11，0
GND I GND
19 9 RESET
I
RESET
3.4 Antenna Specification
3.4.1 On B
oard PCB Antenna
REX3B has
an on board PCB antenna. Notes for using PCB antenna:
 Avoid placing module in a metal shell.
 Keep metal object from the PCB antenna (at least 1cm above, 2.7cm plus recommend).
 Do not keep module nearby the devices with electromagnetic radiation source, such as
transformers.
The design of a user's PCB should prevent the module’s PCB antenna from the interference of its
components, traces and bottom. The basic principles are:
 No traces, bottom around the PCB antenna with no other components placed
 The PCB antenna shall be out of PCB board