Jinan USR IOT Technology USR-WIFI232-S User manual

USR-WIFI232-S/T/G2 Low Power WiFi Module User Manual http://en.usr.cn
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USR-WIFI232-S/T/G2
Low Power WiFi Module User Manual V3.1
Overview of Characteristic
Support IEEE802.11b/g/n Wireless Standards
Based on Self-developed High Performance MCU
Ultra-Low-Power Applications with Excellent Power Save
Support UART/PWM/GPIO Data Communication Interface
Support Work As STA/AP Mode
Support Smart Link Function (APP program provide)
Support USRLINK Function(Fast set SSID)
Support Wireless Upgrade Function
Support WPS Function
Support Multi-TCP Link (5 Channel) Application
Support Internal/External(I-PEX/SMA) Antenna Option
Single +3.3V Power Supply
Smallest Size:
USR-WIFI232-S 22mm x 13.5mm x 2.3mm, SMT Footprint
USR-WIFI232-T 22mm x 13.5mm x 6mm, 1x10 2mm Connector
USR-WIFI232-G2 23.1mm x 32.8mm x 2.7mm, SMT Footprint

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FCC/CE Certificated

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Catalogue
1、Quick start............................................................................................................................................................7
1.1 Hardware connect........................................................................................................................................7
1.2 Network connection..................................................................................................................................... 8
1.3 communication test......................................................................................................................................8
1.4 Application Examples................................................................................................................................ 10
1.4.1 Wireless remote control applications.................................................................................................. 10
1.4.2 Remote connectivity applications........................................................................................................ 10
1.4.3 Transparent Transmission.....................................................................................................................10
2、Product Overview......................................................................................................................................... 12
2.1 General Description...................................................................................................................................12
2.2 Device Features......................................................................................................................................... 12
2.3 Device Paremeters.................................................................................................................................... 13
2.4 Modules feature comparison................................................................................................................... 14
2.5 Key Application...........................................................................................................................................14
2.6 Package Information................................................................................................................................. 15
2.6.1 Recommended Reflow Profile..............................................................................................................15
2.6.2 Device Handling Instruction (Module IC SMT Preparation)............................................................ 15
2.6.3 Shipping Information.............................................................................................................................. 16
3、Hardware Introduction..................................................................................................................................... 17
3.1 Pins Definition.............................................................................................................................................17
3.1.1. USR-WIFI232-S Pins Definition..........................................................................................................17
3.1.2. USR-WIFI232-T Pins Definition.......................................................................................................... 19
3.1.3. USR-WIFI232-G2 Pins Definition....................................................................................................... 21
3.2 Electrical Characteristics.......................................................................................................................... 24
3.3 Mechanical Size......................................................................................................................................... 24
3.3.1 USR-WIFI232-S......................................................................................................................................24
3.3.2 USR-WIFI232-T...................................................................................................................................... 25
3.3.3 USR-WIFI232-G2................................................................................................................................... 26
3.4 Antenna........................................................................................................................................................27
3.4.1 USR-WIFI232-S......................................................................................................................................27
3.4.2 USR-WIFI232-T...................................................................................................................................... 28
3.4.3 USR-WIFI232-G2................................................................................................................................... 29
3.5 Evaluation Kit..............................................................................................................................................30
3.6 Typical Application Hardware...................................................................................................................31
3.6.1 UART Application Hardware.................................................................................................................31
3.6.2 PWM/GPIO Application Hardware.......................................................................................................31
4、Modules function description..........................................................................................................................32
4.1 Work Mode..................................................................................................................................................32
4.1.1 Throughput mode................................................................................................................................... 32
1. Throughput mode brief introduction..........................................................................................32
2. UART Frame Scheme.................................................................................................................33
4.1.2 Command Mode..................................................................................................................................... 34

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4.1.3 GPIO/PWM Mode...................................................................................................................................34
4.2 Wireless Networking..................................................................................................................................35
4.2.1 STA WI-FI Mode......................................................................................................................................36
4.2.2 AP WI-FI Mode........................................................................................................................................36
4.2.3 Encryption................................................................................................................................................36
4.3 Socket Communication.............................................................................................................................37
4.3.1 Socket A................................................................................................................................................... 37
4.3.2 Socket B...................................................................................................................................................37
4.4 Fast access Wi-Fi(usrlink)........................................................................................................................38
4.5 Searching Wi-Fi protocol & Network AT Command............................................................................. 41
4.6 Reporting MAC...........................................................................................................................................41
4.7 D2D function............................................................................................................................................... 41
4.8 HTTPD Function........................................................................................................................................ 42
4.9 RS485 Function......................................................................................................................................... 44
4.10 Parameter configuration......................................................................................................................... 44
4.11 Firmware and web upgrade................................................................................................................... 44
5、Module Parameter configuration................................................................................................................... 45
5.1 Web.............................................................................................................................................................. 45
5.1.1 Web Brief Description............................................................................................................................ 45
5.1.2 Open Web Management Interface...................................................................................................... 45
5.1.3 Fast Set SSID Page(usrlink).................................................................................................................46
5.1.4 System Page........................................................................................................................................... 47
5.1.5 STA Setting Page................................................................................................................................... 47
5.1.6 AP Setting Page......................................................................................................................................48
5.1.7 Network Setting Page............................................................................................................................ 49
5.1.8 UART Setting Page................................................................................................................................ 49
5.1.9 Account Management Page................................................................................................................. 49
5.1.10 Upgrade Software Page......................................................................................................................50
5.1.11 Restart Page..........................................................................................................................................50
5.1.12 Restore Page........................................................................................................................................ 51
5.2 AT command............................................................................................................................................... 51
5.2.1 Switch to Command Mode....................................................................................................................52
5.2.2 AT command Overview..........................................................................................................................53
5.2.3 AT command introduction......................................................................................................................54
1) AT+E.......................................................................................................................................................56
2) AT+WMODE......................................................................................................................................... 57
3) AT+ENTM..............................................................................................................................................57
4) AT+TMODE...........................................................................................................................................57
5) AT+MID.................................................................................................................................................. 57
6) AT+RELD...............................................................................................................................................58
7) AT+Z.......................................................................................................................................................58
8) AT+H...................................................................................................................................................... 58
9) AT+CFGTF............................................................................................................................................ 58
10) AT+UART............................................................................................................................................ 58

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11) AT+UARTF.......................................................................................................................................... 59
12) AT+UARTFT....................................................................................................................................... 59
13) AT+UARTFL........................................................................................................................................59
14) AT+UARTTE....................................................................................................................................... 59
15) AT+PING............................................................................................................................................. 60
16) AT+SEND............................................................................................................................................60
17) AT+RECV............................................................................................................................................60
18) AT+NETP............................................................................................................................................ 60
19) AT+MAXSK......................................................................................................................................... 61
20) AT+TCPLK.......................................................................................................................................... 61
21) AT+TCPTO..........................................................................................................................................62
22) AT+TCPDIS........................................................................................................................................ 62
23) AT+SOCKB......................................................................................................................................... 62
24) AT+TCPDISB......................................................................................................................................63
25) AT+TCPTOB.......................................................................................................................................63
26) AT+TCPLKB....................................................................................................................................... 64
27) AT+SNDB............................................................................................................................................64
28) AT+RCVB............................................................................................................................................64
29) AT+WSSSID....................................................................................................................................... 64
30) AT+WSKEY.........................................................................................................................................64
31) AT+WANN........................................................................................................................................... 65
32) AT+WSMAC........................................................................................................................................65
33) AT+WSLK............................................................................................................................................66
34) AT+WSLQ........................................................................................................................................... 66
35) AT+WSCAN........................................................................................................................................ 66
36) AT+WSDNS........................................................................................................................................ 66
37) AT+LANN............................................................................................................................................ 67
38) AT+WAP.............................................................................................................................................. 67
39) AT+WAKEY.........................................................................................................................................67
40) AT+WAMAC........................................................................................................................................68
41) AT+WADHCP..................................................................................................................................... 68
42) AT+WALK............................................................................................................................................68
43) AT+WALKIND.....................................................................................................................................68
44) AT+PLANG......................................................................................................................................... 69
45) AT+WEBU........................................................................................................................................... 69
46) AT+NTPRF..........................................................................................................................................69
47) AT+NTPEN......................................................................................................................................... 70
48) AT+NTPTM......................................................................................................................................... 70
49) AT+DTDDIS........................................................................................................................................ 70
50) AT+DTDID...........................................................................................................................................70
51) AT+HTPEN......................................................................................................................................... 71
52) AT+HTPTP..........................................................................................................................................71
53) AT+HTPSV..........................................................................................................................................71
54) AT+HTPHD......................................................................................................................................... 72

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55) AT+HTPURL....................................................................................................................................... 72
56) AT+HTPTO..........................................................................................................................................72
57) AT+HTPFT.......................................................................................................................................... 73
58) AT+WRMID......................................................................................................................................... 73
59) AT+ASWD........................................................................................................................................... 73
60) AT+MDCH........................................................................................................................................... 73
61) AT+TXPWR.........................................................................................................................................74
62) AT+WPS..............................................................................................................................................74
63) AT+WPSBTNEN................................................................................................................................ 74
64) AT+SMTLK..........................................................................................................................................74
65) AT+LPTIO........................................................................................................................................... 75
66) AT+USERVER....................................................................................................................................75
67) AT+CUSTOMER................................................................................................................................ 75
68) AT+RPTMAC...................................................................................................................................... 75
69) AT+WRRPTMAC............................................................................................................................... 76
70) AT+WIFI...............................................................................................................................................76
71) AT+WIFICHK...................................................................................................................................... 76
72) AT+CHKTIME..................................................................................................................................... 76
73) AT+RSEN............................................................................................................................................77
Appendix A: HW Reference Design...................................................................................................................... 78
USR-WIFI232-S Evaluation Kit Schematic.................................................................................................. 78
USR-WIFI232-T Evaluation Kit Schematic...................................................................................................79
USR-WIFI232-G2 Evaluation Kit Schematic................................................................................................80
Appendix B: GPIO/PWM CONTROL WITH NETWORK COMMANDS.......................................................... 81
Appendix C: Contact Information.....................................................................................................................86
Appendix D: Disclaimer........................................................................................................................................... 86
Appendix E: Update History....................................................................................................................................86

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1、Quick start
USR-WIFI232 series product is used to transmit data between RS232 and WIFI
TCPIP transparently, user can update the product to WIFI control without knowing the
WIFI and TCPIP detail. All the convert work is done by the module. For users, the
RS232 side is only as a serial device,the WIFI side is TCPIP Socket data. User can
setup the work detail by sample settings which can setup via inside web pages or
RS232 port. The setup work only need do once, then it will save the setting forever.
This chapter is a user guide for USR-WIFI232 series products. We suggest users
follow the guide to test module at first, and will have a good understanding of the
modules. Users can also choose the chapter which you are interested in to read. For
specific details and instructions, please refer to the following chapters.
Support：http://h.usriot.com
1.1 Hardware connect
In order to test WIFI module, we need connect module RS232 to PC and also
WIFI to PC.
In order to test the communication between serial and WIFI network, we need to
connect the serial port to PC, and also connect WIFI networks to PC. Due to the
special need both WIFI and serial, we use PC which add USB WIFI network Card
such as the following picture.
RS232
WIFI
Figure 1 hardware connection diagram
About the serial connection, because the module RS232 is 3.3V TTL level, the
computer can not connect to module directly, the user needs to have a TTL to RS232
adapter cable and then connect to the computer. in order to facilitate the test, we
provide USR-WIFI232-S/T/G2 evaluation board for users to choose.

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1.2 Network connection
The following is the USR-WIFI232-T module example, except SSID, other
modules are the same to USR-WIFI232-T. Open Wi-Fi, search network, as shown in
below, USR-WIFI232-T is the default network name (SSID) of the module.
Figure 2 WIFI Search
Join the network, choose to automatically obtain IP, WIFI module supports DHCP
Server feature and is enabled by default.
Figure 3 WIFI connection
Now, nlink led of USR-WIFI232-T Evaluation Board is lighting.
1.3 communication test
Module’s default setting:
SSID: USR-WIFI232-T;

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Encryption mode: open,none;
UART: 115200,8,1,None;
Network parameters: TCP,Server,8899,10.10.100.254;
IP: DHCP,0.0.0.0,0.0.0.0,0.0.0.0
We just need to follow the parameters of the corresponding set of network
communication parameters, you can make serial <--> WIFI communication, the steps
are as follows:
1. Open test software USR-TCP232-Test;
2. COM Settings area (left):
Choose COM port witch has connect the module, there is COM3, choose
band rate to 115200, this is the default band rate of WIFI module, Click Open
COM port.
3. Net Settings area (right):
Choose TCP client mode, Server IP write 10.10.100.254, it is the WIFI default
IP address, Server port to 8899, It is the default Port the WIFI module listen,
Click Connect to link to the module.
Now, you can test send data between RS232 and WIFI.
COM port to WIFI: PC RS232 -> Module RS232 -> Module WIFI -> PC WIFI,
WIFI to COM port: PC WIFI -> Module WIFI -> Module RS232 -> PC RS232.
Figure 4 serial / network parameter settings and transmission test

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1.4 Application Examples
1.4.1 Wireless remote control applications
Figure 5 Wireless remote control applications
In the wireless remote control applications, USR-WIFI232 module works in AP
mode. USR-WIFI232 module’s serial connect user’s devices. Control client (such as
smartphones) can controll the user equipment via wireless network.
1.4.2 Remote connectivity applications
Figure 6 Remote connectivity applications
In remote connection applications, USR-WIFI232 module works in the STA mode,
connect to internet through internet gateway. Module is set to TCP Client, connected
to the internet TCP server. User devices connected to USR-WIFI232 module through
the serial port.
This application can collect data from the user device and send it to the server for
processing and storage, the internet server can also send commands to control the
user device for control. Users can use smartphone or PC to control the user device via
LAN, and also can control the user device via WAN by communicate to internet
server.
1.4.3 Transparent Transmission
In this application, two USR-WIFI232 modules connecet by Wi-Fi as shown below,

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this application is to build a transparent serial channel between two user devices.
The following figure is set as follows:
Left of the USR-WIFI232 module is set to AP mode, SSID and IP address are
default, network protocol is set to TCP / Server mode, protocol port is 8899 by
defaults.
Right of the USR-WIFI232 module is set to STA mode, SSID is set to the AP's
SSID which will be connected to (eg USR-WIFI232-T), the IP address is
DHCP by default, network protocol is set to TCP / Client mode, protocol port
8899, Target IP address is set to the left of the module, i.e. 10.10.100.254.
When the right side module startup will find AP (SSID: USR-WIFI232-T), and then
automatically connect to the left side TCP server as client. All connections can
compelet automatically, both sides of the UART can transparently transmit data.
Figure 7 Transparent serial

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2、Product Overview
2.1 General Description
USR-WIFI232-S/T/G2 is a fully self-contained small form-factor, single stream,
802.11b/g/n Wi-Fi module, which provide a wireless interface to any equipment with a
Serial interface for data transfer.
USR-WIFI232-S/T/G2 integrate MAC, baseband processor, RF transceiver with
power amplifier in hardware and all Wi-Fi protocol and configuration functionality and
networking stack, in embedded firmware to make a fully self-contained 802.11b/g/n
Wi-Fi solution for a variety of applications.
USR-WIFI232-S/T/G2 adopts the world's lowest power consumption embedded
architecture. It has been optimized for all kinds of client applications in the home
automation, smart grid, handheld device, personal medical application and industrial
control that have lower data rates, and transmit or receive basis data at low rate.
USR-WIFI232-S/T/G2 integrates all Wi-Fi functionality into a low-profile, small
module package that can be easily mounted on main PCB with application specific
circuits. Also, module provides built-in antenna, external antenna option. The following
is the size of module.
USR-WIFI232-S 22mm x 13.5mm x 2.3mm, SMT Footprint
USR-WIFI232-T 22mm x 13.5mm x 6mm, 1x10 2mm Connector
USR-WIFI232-G2 23.1mm x 32.8mm x 2.7mm, SMT Footprint
2.2 Device Features
Support IEEE802.11b/g/n Wireless Standards
Support WIF[email protected] GHz, support WEP, WPA/WPA2 security mode.
Based on Self-developed High Performance MCU
Ultra-Low-Power for Battery Applications with Excellent Power Save Scheme
Support UART/PWM/GPIO Data Communication Interface
Support Work As STA/AP Mode
Support SmartLink Function (APP program provide)
Support usrlink Function(Fast set SSID)
Support Wireless Upgrade Function
Support WPS Function
Support Multi-TCP Link (5 Channel) Apllication
Support Internal/External(I-PEX/SMA) Antenna Option
Single +3.3V Power Supply
Smallest Size
FCC/CE Certificated

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2.3 Device Paremeters
Table 1 USR-WIFI232-S/T/G2 Module Technical Specifications
Class
Item
Parameters
Wireless
Parameters
Certification
FCC/CE
Wireless
standard
802.11 b/g/n
Frequency range
2.412GHz-2.484GHz
Transmit Power
802.11b: +16 +/-2dBm (@11Mbps)
802.11g: +14 +/-2dBm (@54Mbps)
802.11n: +13 +/-2dBm (@HT20, MCS7)
Receiver
Sensitivity
802.11b: -93 dBm (@11Mbps ,CCK)
802.11g: -85 dBm (@54Mbps, OFDM)
802.11n: -82 dBm (@HT20, MCS7)
Antenna Option
External：I-PEX connector（WIFI232-T/G2）
SMA connector （WIFI232-S）
Internal：On-board PCB antenna
（WIFI232-S/G2）
Hardware
Parameters
Data Interface
UART
PWM/GPIO
SPI(Reserved)
Operating
Voltage
3.0~3.6V
Operating
Current
Peak [Continuous TX]: ~200mA
Average. ~12mA, Peak: 200mA
Standby [WiFi Shutdown]: <200uA(Reserved)
Operating Temp.
-40℃- 85℃
Storage Temp.
-45℃- 125℃
Dimensions and
Size
22mm x 13.5mm x 2.3mm（WIFI232-S）
22mm x 13.5mm x 6mm（WIFI232-T）
23.1mm x 32.8mm x 2.7mm（WIFI232-G2）
Footprint
1x10, 2mm connector（WIFI232-T）
SMT（WIFI232-S/G2）
Software
Parameters
Network Type
STA/AP/STA+AP
Security
Mechanisms
WEP/WPA-PSK/WPA2-PSK
Encryption
WEP64/WEP128/TKIP/AES
Update
Firmware
Local Wireless
Customization
Web Page Upgrade
Network Protocol
IPv4, TCP/UDP/HTTP
User
AT+command

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Configuration
Website (except WIFI232-S)
Android/iOS APP,
Smart Link APP tools
2.4 Modules feature comparison
Listed below are the basic functions of USR-WIFI232 low-power series:
Table 2 USR-WIFI232-S/T/G2Modules feature comparison
Feature
USR-WIFI232-S
USR-
WIFI23
2-T
USR-WIFI232-G2
-Sa
-Sb
-G2a
-G2b
WIFI
AP
√
√
√
√
√
STA
√
√
√
√
√
Socket
SocketA
√
√
√
√
√
SocketB
√
√
√
√
√
UART-WIFI
Transparent
transmission
√
√
√
√
√
Embedded Web
No
No
√
√
√
AT+command
√
√
√
√
√
UART hardware
flow control
√
√
No
√
√
Smartlink
√
√
√
√
√
Audio Network
Configuration
No
No
No
No
No
WPS
√
√
√
√
√
PWM
No
No
3
4
4
GPIO
1
1
3
6
6
Antenna Option
On-boar
d PCB
antenna
SMA
connecto
r
I-PEX
connect
or
On-boar
d PCB
antenna
I-PEX
connecto
r
Note：
WIFI232-T/G2’s PWM/GPIO pin is multiplexed pin.
2.5 Key Application
Remote equipment monitoring
Industrial sensors and controls
Asset tracking and telemetry
Home automation
Medical devices

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2.6 Package Information
2.6.1 Recommended Reflow Profile
Figure 8 Reflow Soldering Profile
Table 3 Reflow Soldering Parameter
Note:
1. Recommend to supply N2 for reflow oven.
2. N2 atmosphere during reflow (O2<300ppm).
2.6.2 Device Handling Instruction (Module IC SMT Preparation)
Shelf life in sealed bag: 12 months, at <30℃and <60% relative humidity
(RH)
After bag is opened, devices that will be re-baked required after last
baked with window time 168 hours.
Recommend to oven bake with N2 supplied.
Baked required with 24 hours at 125±5℃before rework process for two
modules, one is new module and two is board with module.
Recommend to store at ≦10% RH with vacuum packing.
If SMT process needs twice reflow:
(1) Top side SMT and reflow (2) Bottom side SMT and reflow
Case 1: Wifi module mounted on top side. Need to bake when bottom
side process over 168 hours window time, no need to bake within
168 hours.
Case 2: Wifi module mounted on bottom side, follow normal bake rule
before process.
Note:
Window time means from last bake end to next reflow start that has 168
hours space.
NO.
Item
Temperature (Degree)
Time(Sec)
1
Reflow Time
Time of above 220℃
35~55 sec
2
Peak-Temp
260℃max

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2.6.3 Shipping Information
Figure 9 Shipping Information
TRAY Size: 420*245*34 mm
Note:
1 tray = 5*20 pcs = 100 pcs
1 box = 2 trays = 2*100 pcs = 200pcs
1 carton = 4 boxes = 4*200 pcs = 800pcs

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3、Hardware Introduction
3.1 Pins Definition
3.1.1. USR-WIFI232-S Pins Definition
Figure 10 USR-WIFI232-S View
Figure 11 USR-WIFI232-S Pins Map
Table 4 USR-WIFI232-S Pins Definition
Pin
Describtion
Net Name
Signal
Type
Comments
1
SPI Data Out
SPI_MOSI
0
SPI Interface（Reserved)
2
SPI Clock
SPI_CLK
I/O
3
SPI Data Out
SPI_MISO
I
4
SPI CS
SPI_CS
I/O
5
UART0
UART0_TX
O
UART Interface
6
UART0
UART0_RX
I
7
UART0
UART0_CTS
I/O
8
UART0
UART0_RTS
I/O
9
GPIO
GPIO
I/O
GPIO23，No connect if not use
10
Module Reset
nReset
I
Low effective reset input. Pull-up
if not use.
11
Module Boot Up
nReady
O
0 – Boot-up OK;

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Indicator
1 – Boot-up No OK;
No connect if not use.
12
Module Recovery
nReload
I
Low effective reset input. Pull-up
if not use.
Can be set to Smart Link Pin
13
Wi-Fi Status
nLink
O
0- Wi-Fi Link.
1- No WIFI Link.
No connect if not use.
14
WPS
WPS
I
WPS Function Pin.
Pull-up if not use.
15
+3.3V Power
DVDD
Power
16
Ground
GND
Power
17
2.4GHz antenna
PAD
ANT_2.4G
O
Must be 50ohm impedance
< Explanation >:
I—IN; O—OUT; PU—PULL-UP; I/O—IN/OUT GPIO;
< The main pin function description>
nReset:
Module reset pin, input GPIO, low effective.
Module nReset need pull-up when module works. If MCU module needs to do a reset
operation, pull low for at least 10ms and then pull up.
nReload:
Module recover factory settings pin, input GPIO, low effective.
1) After module is powered up, short press this button (Low < 3s) to make the module
go into “Smart Link” config mode, waiting for APP to set password and other
information.
2) After module is powered up, long press this button (Low > 3s) to make the module
recover to factory setting.
Note：
1.When designing the circuit, please use the stable connection, such as light touch
switches, and increase the appropriate filter circuit, or module can't restore factory
settings stably.
2.nReset and nReload need 5 kohm ~ 10 kohm pull-up resistor
nLink:
Wi-Fi link status indicator pin, output GPIO,low effective. USR strongly suggest customer
connect out this pin to LED.
1) At “Smart Link” config mode, this LED used to indicate APP to finish setting.
2) At normal mode, it’s Wi-Fi link status indicator
nReady:
Module startup success indicator pin, output GPIO, low effective. Can be connected out
to led.
WPS:
WPS function start pin, input GPIO, low effective. Can be connected to key.
UART0_TX/RX/CTS/RTS:

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UART pin
GPIO n:
GPIO which can be controlled by network cammands, n is control index number.
3.1.2. USR-WIFI232-T Pins Definition
Figure 12 USR-WIFI232-T view
Figure 13 USR-WIFI232-T pin map
Table 5 USR-WIFI232-T Pins Definition
Pin
Describtion
Net Name
Signal Type
Comments
1
Ground
GND
Power
2
+3.3V Power
DVDD
Power
3.3V@250mA
3
Module
Recovery
nReload
I
Low effective reset input.
Pull-up if not use.
Can be set to Smart Link Pin
4
Module Reset
nReset
I
Low effective reset input.
Pull-up if not use.
5
UART
UART_RX
I
No connect if not use.
6
UART
UART_TX
O
No connect if not use.
7
Power soft
switch
PWR_SW
I,PU
“0” – Power Down Mode
“1” – Normal mode
(Function is reserved)
8
PWM/WPS
PWM_3
I/O
Default WPS function,
Can be set to PWM/GPIO18.
No connect if not use.
9
PWM/nReady
PWM_2
I/O
Default nReady function,
Can be set to PWM/GPIO12.

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No connect if not use.
10
PWM/nLink
PWM_1
I/O
Default nLink function,
Can be set to PWM/GPIO11.
No connect if not use.
< Explanation >:
I—IN;O—OUT; PU—PULL-UP; I/O—IN/OUT GPIO;
< The main pin function description>
nReset:
Module reset pin, input GPIO, low effective.
Module nReset need pull-up when module works. If MCU module needs to do a reset
operation, pull low for at least 10ms and then pull up.
nReload:
Module recovery factory settings pin, input GPIO, low effective.
1) After module is powered up, short press this button (Low < 3s) to make the module
go into “Smart Link” config mode, waiting for APP to set password and other
information.
2) After module is powered up, long press this button (Low > 3s) to make the module
recover to factory setting.
Note：
1.When designing the circuit, please use the stable connection, such as light touch
switches, and increase the appropriate filter circuit, or module can't restore factory
settings stably.
2.nReset and nReload need 5 kohm ~ 10 kohm pull-up resistor
nLink:
Wi-Fi link status indicator pin, output GPIO,low effective. USR strongly suggest customer
connect out this pin to LED.
1) At “Smart Link” config mode, this LED used to indicate APP to finish setting.
2) At normal mode, it’s Wi-Fi link status indicator.
nReady:
Module startup success indicator pin, output GPIO, low effective. Can be connected out
to led.
WPS:
WPS function start pin, input GPIO, low effective. Can be connected to key.
UART0_TX/RX/CTS/RTS：
UART pin
GPIO n:
GPIO which can be controlled by network commands, n is control index number.
PWM_N:
Module PWM signal output pin. Can also be configured as GPIO pin. Can switch
PWM_1 function to nLink, PWM_2 function to nReady, PWM_3 function to WPS
keys, by AT command "AT + LPTIO = on". "AT + LPTIO = off" is the opposite.