WR4 Module Datasheet

Last Updated on2020-04-25 06:50:52

Product Overview

​ WR4 is a low power-consuming built-in Wi-Fi module developed by Hangzhou Tuya Information Technology Co., Ltd. It consists of a highly integrated wireless radio chip (RTL8710BN) and an external flash chip, with a built-in Wi-Fi network protocol stack and robust library functions. WR4 also contains a low power-consuming ARM CM4F, a WLAN MAC, a 1T1R WLAN, a basic frequency of up to 125 MHz, a 256 KB SRAM, a 1 MB flash, and various peripheral resources.

​ WR4 is an RTOS platform that integrates all the function libraries of the Wi-Fi MAC and TCP/IP protocols. You can develop built-in Wi-Fi products as required.

​ Figure 1.1 shows the architecture of WR4.

WR4 Module Datasheet


Built-in low power-consuming 32-bit CPU, which can also be used as an application processor

  • Basic frequency: 125 MHz

Working voltage:3 V to 3.6 V

Peripherals: nine GPIOs, one UART, and one ADC

Wi-Fi connectivity

  • 802.11 B/G/N20/N40

  • Channel 1–14@2.4 GHz

  • WPA/WPA2 security mode supported

  • +20 dBm output power in 802.11b mode

  • SmartConfig function supported (for Android and iOS devices)

  • IPEX connector for external antennas

  • Certified by CE, FCC, and SRRC

  • Working temperature: –40°C to +85°C

  • AES 128/256-based hardware encryption

Major Application Fields

  • Intelligent building
  • Intelligent home and household applications
  • Health care
  • Industrial wireless control
  • Baby monitor
  • Network camera
  • Intelligent bus

Module Interfaces

Dimensions and Footprint

​ WR4 provides two rows of pins (2 x 8) with the distance of 1.5 mm between every two pins.

​ WR4 dimensions: 13.8 mm (W) x 15.5 mm (L) x 3.3 mm (H) (see figure 2.1)

Figure 2.1 WR4 dimensions WR4 Module Datasheet

Pin Definition

Table 2.1 describes the common pins. ​ Table 2.1 WR4 pins

PinSymbolI/O TypeFunctions
1NC/NC, not connected
2ADCAIADC interface, with the maximum output power of 5 V
3ENI/OThe pin function is disabled by firmware, user can choose not to connect.
6A_0I/OGPIOA_0, which cannot be pulled up during power-on and can be configured after power-on
83.3 VPModule power supply pin (3.3 V)
9GNDPPower supply reference ground pin
10A_23I/OUART0_TXD (user's serial port)
11A_18I/OUART0_RXD (user's serial port)
15A_29I/OUART_Log_RXD (used for printing of the module internal information), which can also be used as the GPIO
16A_30I/OUART_Log_TXD (used for printing of the module internal information), which can also be used as the GPIO

Note: P indicates power-supply pins, I/O indicates input/output pins, and AI indicates analog input pins.


Absolute Electrical Characteristics

​ Table 3.1 Absolute electrical characteristics

ParametersDescriptionMinimum valueMaximum valueUnit
TsStorage temperature-40105
VDDPower supply voltage-0.33.6V
Static electricity voltage (human model)TAMB-25℃-2KV
Static electricity voltage (machine model)TAMB-25℃-0.5KV

Electrical conditions

Table 3.2 Normal electrical conditions

ParameterDescriptionMinimum ValueTypical ValueMaximum ValueUnit
TaWorking temperature–20-85°C
VDDWorking voltage3.0-3.6V
VILI/O low-level input–0.3-VDD*0.25V
VIHI/O high-level inputVDD*0.75-3.6V
VOLI/O low-level output--VDD*0.1V
VOHI/O high-level outputVDD*0.8-VDDV
ImaxI/O drive current--16mA
CpadInput pin capacitor-2-pF

Wi-Fi TX Power Consumption

​ Table 3.3 TX power consumption during constant emission

SymbolModePowerTypical ValueUnit
IRF11b11 Mbit/s17 dBm287mA
IRF11b11 Mbit/s18 dBm295mA
IRF11g54 Mbit/s15 dBm255mA
IRF11g54 Mbit/s17.5 dBm267mA
IRF11n BW20MCS713 dBm244mA
IRF11n BW20MCS716.5 dBm257mA
IRF11n BW40MCS713 dBm220mA
IRF11n BW40MCS716.5 dBm230mA

Note: When the preceding data is used for testing, the amount of constantly emitted data (duty cycle) is 100%.

Wi-Fi RX Power Consumption

​ Table 3.4 RX power consumption during constant emission

SymbolModeTypical ValueUnit
IRFCPU sleep90mA
IRFCPU active120mA

Power Consumption in Operating Mode

​ Table 3.5 Module working current

Working ModeWorking Status (Ta = 25°C)Typical ValuePeak Value*Unit
EZ modeThe module is in EZ status and the Wi-Fi indicator quickly flashes.115130mA
Idle modeThe module is in connected status and the Wi-Fi indicator is steady on.50110mA
Operation modeThe module is in connected status and the Wi-Fi indicator is steady on.120265mA
Disconnection modeThe module is in disconnected status and the Wi-Fi indicator is steady off.3590mA

Note: The peak duration is about 5 µs. ​ The preceding parameter values vary depending on the firmware functions.

RF Features

Basic RF Features

​ Table 4.1,Basic RF features

Frequency range2.400–2.4835 GHz
Wi-Fi standardIEEE 802.11b/g/n (channel 1–14)
Data transmitting rate11b: 1, 2, 5.5, 11 (Mbit/s)11g: 6, 9, 12, 18, 24, 36, 48, 54 (Mbit/s)11n: HT20 MCS0–MCS711n: HT40 MCS0–MCS7
Antenna typeExternal antenna connected through the U.FL RF connector

WI-FI Output Power

​ Table 4.2 TX power during constant emission

Parameter Minimum ValueTypical ValueMaximum ValueUnit
RF average output power, 802.11b CCK mode11M-17.5-dBm
RF average output power, 802.11g OFDM mode54M-14.5-dBm
RF average output power, 802.11n OFDM modeMCS7-13.5-dBm
Frequency error -10-10ppm

WI-FI RX sensitivity

​ Table 4.3 RX Sensitivity

Parameter Minimum ValueTypical ValueMaximum ValueUnit
PER < 8%, RX sensitivity, 802.11b CCK mode11M-–91-dBm
PER < 10%, RX sensitivity, 802.11g OFDM mode54M-–75-dBm
PER < 10%, RX sensitivity, 802.11n OFDM modeMCS7-–72-dBm

Antenna Information

Antenna types

​ The FPC antenna is recommended. Figure 5.1 shows the recommended antenna connection method and the dimensions. You can also select standard antennas based on the product assembly method.

WR4 Module Datasheet

Antenna Interference Reduction

​ To ensure optimal Wi-Fi performance when the Wi-Fi module uses the onboard PCB antenna, it is recommended that there be a space of at least 15 mm between the module antenna and other metal parts.

U.FL RF connector

Figure 5.2 shows the U.FL RF connector parameters. WR4 Module Datasheet

Packaging Information and Poduction Instructions

Mechanical Dimensions

WR4 Module Datasheet

Recommended PCB Encapsulation

WR4 Module Datasheet

Production Instructions

Storage conditions of a delivered module are as follows:

  1. The anti-moisture bag is placed in an environment where the temperature is under 30°C and the relative humidity is under 85%.
  2. The shelf life of a dry-packaged product is six months from the date when the product is packaged and sealed.


  1. Throughout the production process, each involved operator must wear an electrostatic ring.
  2. During the operation, strictly protect the module from water and strains.

Recommended Oven Temperature Profile

WR4 Module Datasheet

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