WR4 Module Datasheet

Last Updated on : 2021-09-11 06:46:44download

WR4 is a low power-consumption built-in Wi-Fi module developed by Tuya. It consists of a highly integrated RF chip (RTL8710BN) and an external flash chip, with a built-in Wi-Fi network protocol stack and rich library functions.


WR4 also contains a low power-consumption ARM CM4F, a WLAN MAC, a 1T1R WLAN, a basic frequency of up to 125 MHz, 256-KB SRAM, 1-MB flash memory, and rich 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

  • Operating voltage:3 V to 3.6 V

  • Peripherals: 9 GPIOs, 1 UART, and 1 ADC

  • Wi-Fi connectivity

    • 802.11 B/G/N20/N40

    • Channel 1–14@2.4 GHz

    • WEP, WPA, WPA2, and WPA2 PSK (AES) security modes 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

    • Operating 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 has two lines of pins (2 x 8) with a distance of 1.5 mm between every two pins.

WR4 dimensions: 13.8±0.35 mm (W)×15.5±0.35 mm (L) ×3.4±0.15 mm (H)

WR4 Module Datasheet

Pin definition

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.

Electrical parameters

Absolute electrical parameters

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

Working conditions

Parameter Description Minimum value Typical value Maximum value Unit
Ta Operating temperature –20 - 85 °C
VDD Operating 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

Working status Mode Rate Transmit power/Receive Average value Peak value (Typical value) Unit
Transmit 11b 11Mbps +17dBm 287 367 mA
Transmit 11b 11Mbps +18dBm 295 382 mA
Transmit 11g 54Mbps +15dBm 255 406 mA
Transmit 11g 54Mbps +17.5dBm 267 428 mA
Transmit 11n-HT20 MCS7 13dBm 244 395 mA
Transmit 11n-HT20 MCS7 16.5dBm 257 422 mA
Transmit 11n-HT40 MCS7 13dBm 220 393 mA
Transmit 11n-HT40 MCS7 16.5dBm 230 420 mA

Wi-Fi RX power consumption

Symbol Mode Typical value Unit
Receive CPU sleep 90 mA
Receive CPU active 120 mA

Power consumption in operating mode

Woking mode Working status, Ta=25℃ Average value Peak value (Typical 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 value lasts for about 5 µs.

The preceding parameters vary with firmware functions.

RF features

Basic RF features

Parameter Description
Frequency range 2.400 to 2.4835 GHz
Wi-Fi standard IEEE 802.11b/g/n (channels 1 to 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

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

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. The following figure 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

WR4 Module Datasheet

Packaging information and production instructions

Mechanical dimensions

WR4 Module Datasheet

Recommended PCB encapsulation

WR4 Module Datasheet

Production instructions

  • The stamp-hole module must be mounted by the SMT machine. After being unpacked, it must be soldered within 24 hours. Otherwise, it must be put into the drying cupboard where the RH is not greater than 10%, or it needs to be packaged under vacuum again and the exposure time needs to be recorded (the total exposure time cannot exceed 168 hours).

    • SMT equipment:
      • Mounter
      • SPI
      • Reflow soldering machine
      • Oven temperature tester
      • Automated optical inspection (AOI) equipment
    • Baking equipment:
      • Cabinet oven
      • Anti-static heat-resistant pallets
      • Anti-static heat-resistant gloves
  • Storage conditions for a delivered module are as follows:

    • The moisture-proof bag must be placed in an environment where the temperature is below 40°C and the relative humidity is lower than 90%.
    • The shelf life of a dry-packaged product is 12 months from the date when the product is packaged and sealed.
    • The package contains a humidity indicator card (HIC).
      WR4 Module Datasheet
  • The module needs to be baked in the following cases:

    • Vacuum packing bag was found to be damaged before being unpacked.
    • There is no humidity indicator card (HIC) in the vacuum packing bag.
    • After being unpacked, 10% and above circles on the HIC become pink.
    • The total exposure time has been more than 168 hours since unpacking.
    • More than 12 months have passed since the sealing date of the bag.
  • Baking settings:

    • Temperature: 60°C and ≤ 5%RH for reelizing and 125°C and ≤5%RH for palletizing (please use heat-resistant pallet rather than plastic pallet)
    • Time: 48 hours for reelizing and 12 hours for palletizing
    • Alarm temperature: 65°C for reelizing and 135°C for palletizing
    • Production ready temperature after natural cooling: < 36°C
    • The number of drying times: 1
    • Re-baking condition: If a module remains unused for 168 hours after being unpacked, it must be baked again.

      Important: If this batch of modules is not baked within 168 hours, do not use the wave soldering to solder them. Because these modules are 3-level moisture-sensitive components, they are very likely to get damp when exposed outside. In this case, if they are soldered at high temperatures, it may result in component failure or poor soldering.

  • In the whole production process, take electrostatic discharge (ESD) protective measures.

  • To guarantee the passing rate, it is recommended that you use the SPI and AOI to monitor the quality of solder paste printing and mounting.

Recommended oven temperature curve

Perform mounting with the SMT based on the following reflow oven temperature curve. The highest temperature is 245°C. The reflow temperature curve is as below:

WR4 Module Datasheet

  • A: Temperature axis

  • B: Time axis

  • C: Liquidus temperature: 217 to 220°C

  • D: Ramp-up slope: 1 to 3°C/s

  • E: Duration of constant temperature: 60 to 120s; the range of constant temperature: 150 to 200°C

  • F: Duration above the liquidus: 50 to 70s

  • G: Peak temperature: 235 to 245°C

  • H: Ramp-down slope: 1 to 4°C/s

    Note: The above curve is just an example of the solder paste SAC305. For more details about other solder pastes, please refer to Recommended oven temperature curve in the solder paste specifications.

Storage conditions

WR4 Module Datasheet

MOQ and packaging information

Product model MOQ(pcs) Packing method Modules per reel Reels per carton
WR4 4400 Tape reel 1100 4

Appendix: Statement

FCC Caution: Any changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate this device.

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 device has been tested and found to comply with the limits for a Class B digital device, according to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This device generates, uses, and can radiate radio frequency energy and, if not installed and used following 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 device does cause harmful interference to radio or television reception, which can be determined by turning the device 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 device and receiver.
  • Connect the device 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 device complies with FCC radiation exposure limits set forth for an uncontrolled rolled environment. This device should be installed and operated with a minimum distance of 20cm between the radiator and your body.

Important Note

This radio module must not be installed to co-locate and operating simultaneously with other radios in the host system except following FCC multi-transmitter product procedures. Additional testing and device authorization may be required to operate simultaneously with other radios.

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 with 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/warnings 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 has got an FCC ID: 2ANDL-WR4. The 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:

The antenna must be installed such that 20cm is maintained between the antenna and users, and the transmitter module may not be co-located with any other transmitter or antenna.

As long as the 2 conditions above are met, further transmitter tests 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 https://www.tuya.com.

WR4 Module Datasheet

This product must not be disposed of as normal household waste, in accordance with the 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.