Power Interface; Modules Function Description; User Configuration Process - Jinan USR IOT Technology USR-WIFI232-A2 User Manual

USR-WIFI232-A2 User Manual http://www.usriot.com
User can add RS-232 chipset on user board and convert the signal to RS-232 voltage to
communicate with outside equipment or sensors. USR-WIFI232-A2 modules UART interface
include 4 general signals: TXD/RXD/RTS/CTS. The hardware reference design with RS-232
chipset as following:
Figure 10 UART Interface Reference Design
Figure 14
Notes: TXD pin is also hardware configuration pin internal module. So this pin MUST pull-down
during module power up. USR-WIFI232-A2 modules provide internal pull-down resister, user can't
add pull-up/pull-down resister on user board, which may cause module can't work.

3.5.4 Power Interface

USR-WIFI232-A2 module support single +3.3V power supply. The peak current shall about
350mA and normal WiFi working current shall about 200mA. The power save (WiFi OFF) mode
will about 100mA
Decoupling at power pin suggested, At least one 100uF and one 10uF capacitor required at user
board and put near module power input pin will increase the reliability and performance.

4 Modules Function Description

4.1 User configuration process

After USR-WIFI232-A2 module electric starter, based on user pre-set parameters, automatically
connect to wireless networks and servers, and enter the working mode is set to open in
accordance with the default serial port parameters.
The parameters which need to configure include:
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