IoT WiFi module > UART/SPI module > RAK421

Low Power WiFi Module RAK421

RAK421 has low power consumption, both small size and low cost characteristics, rich expansion capabilities, and support for high-speed SPI bidirectional data transfer, easy to use, it can achieve efficient development of IoT.

  • ☼ Small package size: 20.5mm×15.6mm;
  • ☼ Low Power: Standby low to 3mA in the network, the depth of the lowest dormant 1.5uA;
  • ☼ EasyConfig: patent protection, one-key to network connection;
  • ☼ Four-wire SPI interface, support SPI data interrupt pin, Interface actual throughput up to 2Mbps;
  • ☼ Support TCP, UDP protocols, with maximum 8 UDP/TCP connections;
  • ☼ Stable transmission: a single 10MBytes packet is not lost bytes;

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Shenzhen Headquarters

  • Room 1007, Hangsheng Technology Building, South Four Road, Science and Technology Park, Nanshan District, Shenzhen
  • TEL: 0755-86108311
  • Fax: 0755-86152201

Shanghai R&D Center

  • B205 Lvliang Technology Pioneer Park, 2588 Hongmei South Road, Minhang District, Shanghai
  • TEL: 021-61553990
  • Fax: 021-54721038

Beijing Office

  • Tencent Zhongchang Zone, Huilongguan, Changping District, Beijing
Introduction Specifications Application Specifications


RRAK421 module is aWi-Fi module that fully compliant with IEEE 802.11b/g/n wireless standards, with internally integrated TCP / IP protocol stack, supporting numerous protocols such as ARP, IP, ICMP, TCP, UDP, DHCP CLIENT, DHCP SERVER, DNS and other etc. It supports AP mode, Station mode and Ad-hoc and mode. Users can easily and quickly use it to networking and data transmission. Through SPI interface, the module’s maximum transmission rate is up to 2Mbps.

RAK421 supportsstoring parameters, and by the customer commands it determines whether to enable automaticnetworking to realize easy networking and reduce time for system to networking. The module has built-in WEB server, supporting wireless network parametersconfiguration, supporting wireless firmwareupgrade. It also supports WPS and EasyConfig one-key networking, significantly reducing software development effort.

RAK421 has four power management modes, among which the minimum standby power consumption is 2uA, fully meet customer’s requirement for lowpower design.


  • ☼ Support IEEE 802.11b/g/n wireless standards
  • ☼ Support four-wire SPI interface
  • ☼ Support SPI Clock up to Maximum 16Mhz
  • ☼ Minimalist hardware peripheral circuit design
  • ☼ Support Station, Ad-hoc and AP modes
  • ☼ Support OPEN, WEP, WPA-PSK, WPA2-PSK and WPS encryptions
  • ☼ Support TCP, UDP protocols, with maximum 8 UDP/TCP connections
  • ☼ Support webpage-based parameter configuration
  • ☼ Support WPS and EasyConfig one-key to network connection/li>
  • ☼ Support parameter storage, customer orders loading after boot
  • ☼ Support parameters store in Deep Sleep State, with connection time as fastest as 300ms
  • ☼ Support wireless upgrade firmware
  • ☼ On-board ceramic antenna or U.FL antenna connector
  • ☼ Operating voltage: 3.3V
  • ☼ 4 kinds power working modes, with minimum power consumption as1-2uA
  • ☼ Small package size: 20.5mm×15.5mm(curved needle: height 6.4mm; vertical needle: height 8.7mm)
  • ☼ FCC, RoHS and CE compliant


  • ☼ Portable products;
  • ☼ Home appliances and electricalappliances;
  • ☼ Industrial sensors;
  • ☼ Sales terminals;
  • ☼ Buildings automation;
  • ☼ Logistics and freight management;
  • ☼ Home security and automation;
  • ☼ Medical applications, such as patient monitoring, medical diagnostics;
  • ☼ Metering (stop timing, measuring instruments, meters, etc.);


Hardware Information
WIFI Chip Qualcomm AR6K
MCU Nuvoton NANO
RF Parameter
Wireless standard 802.11 b/g/n
Frequency Range 2.412GHz-2.484GHz
Transmitting Power 802.11b: +17 dBm (Max.)
802.11g: +17 dBm (Max.)
802.11n: +17 dBm (Max.)
Receiving Sensitivity 802.11b: -97dBm
802.11g: -91dBm
802.11n: -89dBm
Transmission Speed 802.11b:11 Mbps
802.11g:54 Mbps
802.11n:54 Mbps
Antenna On-board ceramic antenna、External Antenna IPEX
Transmission Distance External maximum 120m (open sight, 2dBI antenna)
Maximum 80 meters onboard antenna (open line of sight)
WIFI Parameter
Wireless network type STA / AP / Ad-hoc Mode
Security Mechanism WEP / WPA-PSK / WPA2-PSK / WAPI
Encryption Type WEP64 / WEP128 / TKIP / AES
Networking Protocol TCP / UDP / ARP / ICMP / DHCP / DNS / HTTP
Maximum number of TCP connections 8
AP maximum number of connections 1
Speed Networking Around 220ms
Communication Interface SPI
Work Pattern Driver source code,SPI
Interface parameters Max 16Mbps, can be configured.
Interface Standard SPI ,3.3V
Electrical Parameters
Working Voltage 3.3V (3.14~3.46)
Working Temperature -40℃~ 85℃(Technical Grade)
Storage Temperature -65℃~ 135℃,5 ~ 95% RH(No Condensation)
Size 20.5mm×15.6mm
Configuration Tools Web configuration, SPI driver library, App key configuration, WPS configuration
Customer Application Provide Android, iOS and SDK on the PC development kit
Provide customer application platform SDK driver source
Hardware reference design
Defects Liability Period 1 Years


Model The maximum
rate of data transfer
TCP/IP Provide
SDK library
Whether to encapsulate
API function
Whether to
port a driver
Whether to
occupy master
control space
How difficult the
programming is
Web WPS EasyConfig
RAK439 8Mb/s Yes Yes Yes Yes Yes More difficult No Yes Yes
RAK411 2Mb/s Yes Yes No Yes Yes Easier Yes Yes Yes
RAK421 2Mb/s Yes Yes No Yes Yes Easier Yes Yes Yes