WR4 Module Datasheet

Last Updated on : 2020-09-29 02:16:28download

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.


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

  • WEP,WPA/WPA2,PSK(AES) 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

Pin Symbol I/O Type Functions
1 NC / NC, not connected
2 ADC AI ADC interface, with the maximum output power of 5 V
3 EN I/O The pin function is disabled by firmware, user can choose not to connect.
4 A_19 I/O GPIOA_19
5 A_12 I/O GPIOA_12
6 A_0 I/O GPIOA_0, which cannot be pulled up during power-on and can be configured after power-on
7 A_5 I/O GPIOA_5
8 3.3 V P Module power supply pin (3.3 V)
9 GND P Power supply reference ground pin
10 A_23 I/O UART0_TXD (user’s serial port)
11 A_18 I/O UART0_RXD (user’s serial port)
12 A_22 I/O GPIOA_22
13 A_15 I/O GPIOA_15
14 A_14 I/O GPIOA_14
15 A_29 I/O UART_Log_RXD (used for printing of the module internal information), which can also be used as the GPIO
16 A_30 I/O UART_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

Parameters Description Minimum value Maximum value Unit
Ts Storage temperature -40 105
VDD Power supply voltage -0.3 3.6 V
Static electricity voltage (human model) TAMB-25℃ - 2 KV
Static electricity voltage (machine model) TAMB-25℃ - 0.5 KV

Electrical conditions

Table 3.2 Normal electrical conditions

Parameter Description Minimum Value Typical Value Maximum Value Unit
Ta Working temperature –20 - 85 °C
VDD Working voltage 3.0 - 3.6 V
VIL I/O low-level input –0.3 - VDD*0.25 V
VIH I/O high-level input VDD*0.75 - 3.6 V
VOL I/O low-level output - - VDD*0.1 V
VOH I/O high-level output VDD*0.8 - VDD V
Imax I/O drive current - - 16 mA
Cpad Input pin capacitor - 2 - pF

Wi-Fi TX Power Consumption

​ Table 3.3 TX power consumption during constant emission

Symbol Mode Power Typical Value Unit
IRF 11b11 Mbit/s 17 dBm 287 mA
IRF 11b11 Mbit/s 18 dBm 295 mA
IRF 11g54 Mbit/s 15 dBm 255 mA
IRF 11g54 Mbit/s 17.5 dBm 267 mA
IRF 11n BW20MCS7 13 dBm 244 mA
IRF 11n BW20MCS7 16.5 dBm 257 mA
IRF 11n BW40MCS7 13 dBm 220 mA
IRF 11n BW40MCS7 16.5 dBm 230 mA

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

Symbol Mode Typical Value Unit
IRF CPU sleep 90 mA
IRF CPU active 120 mA

Power Consumption in Operating Mode

​ Table 3.5 Module working current

Working Mode Working Status (Ta = 25°C) Typical Value Peak Value* Unit
EZ mode The module is in EZ status and the Wi-Fi indicator quickly flashes. 115 130 mA
Idle mode The module is in connected status and the Wi-Fi indicator is steady on. 50 110 mA
Operation mode The module is in connected status and the Wi-Fi indicator is steady on. 120 265 mA
Disconnection mode The module is in disconnected status and the Wi-Fi indicator is steady off. 35 90 mA

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

Parameter Description
Frequency range 2.400–2.4835 GHz
Wi-Fi standard IEEE 802.11b/g/n (channel 1–14)
Data transmitting rate 11b: 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 type External antenna connected through the U.FL RF connector

WI-FI Output Power

​ Table 4.2 TX power during constant emission

Parameter Minimum Value Typical Value Maximum Value Unit
RF average output power, 802.11b CCK mode 11M - 17.5 - dBm
RF average output power, 802.11g OFDM mode 54M - 14.5 - dBm
RF average output power, 802.11n OFDM mode MCS7 - 13.5 - dBm
Frequency error -10 - 10 ppm

WI-FI RX sensitivity

​ Table 4.3 RX Sensitivity

Parameter Minimum Value Typical Value Maximum Value Unit
PER < 8%, RX sensitivity, 802.11b CCK mode 11M - –91 - dBm
PER < 10%, RX sensitivity, 802.11g OFDM mode 54M - –75 - dBm
PER < 10%, RX sensitivity, 802.11n OFDM mode MCS7 - –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

Storage Conditions

WR4 Module Datasheet

MOQ and Packaging Information

Product number MOQ(pcs) Shipping packaging method Modules per reel (pcs) Packaging reels per box (reels)
WR4 4400 Tape reel 1100 4


FCC Caution: Any changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate this equipment.
This device complies with Part 15 of the FCC Rules.Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.
Note: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules.These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:
—Reorient or relocate the receiving antenna.
—Increase the separation between the equipment and receiver.
—Connect the equipment into an outlet on a circuit different from that to which
the receiver is connected.
—Consult the dealer or an experienced radio/TV technician for help.
Radiation Exposure Statement
This equipment complies with FCC radiation exposure limits set forth for an uncontrolled rolled environment. This equipment should be installed and operated with minimum distance 20cm between the radiator and your body.
Important Note
This radio module must not installed to co-locate and operating simultaneously with other radios in host system except in accordance with FCC multi-transmitter product procedures. Additional testing and equipment authorization may be required to operating simultaneously with other radio.
The availability of some specific channels and/or operational frequency bands are country dependent and are firmware programmed at the factory to match the intended destination. The firmware setting is not accessible by the end user.
The host product manufacturer is responsible for compliance to any other FCC rules that apply to the host not covered by the modular transmitter grant of certification. The final host product still requires Part 15 Subpart B compliance testing with the modular transmitter installed.
The end user manual shall include all required regulatory information/warning as shown in this manual, including: This product must be installed and operated with a minimum distance of 20 cm between the radiator and user body.
This device have got a FCC ID:2ANDL-WR4.The final end product must be labeled in a visible area with the following: “Contains Transmitter Module FCC ID: 2ANDL-WR4”
This device is intended only for OEM integrators under the following conditions:
1)The antenna must be installed such that 20cm is maintained between the antenna and users, and
2) The transmitter module may not be co-located with any other transmitter or antenna.
As long as 2 conditions above are met, further transmitter test will not be required. However, the OEM integrator is still responsible for testing their end-product for any additional compliance requirements required with this module installed.
Declaration of Conformity European notice
WR4 Module Datasheet
Hereby, Hangzhou Tuya Information Technology Co., Ltd declares that this module product is in compliance with essential requirements and other relevant provisions of Directive 2014/53/EU,2011/65/EU.A copy of the Declaration of conformity can be found at
WR4 Module Datasheet

This product must not be disposed of as normal household waste, in accordance with EU directive for waste electrical and electronic equipment (WEEE- 2012/19/EU). Instead,it should be disposed of by returning it to the point of sale, or to a municipal recycling collection point.

The device could be used with a separation distance of 20cm to the human body.

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