WR3L Module Datasheet

Last Updated on : 2022-08-23 10:32:15download

WR3L is a low power built-in Wi-Fi module developed by Hangzhou Tuya Information Technology Co., Ltd. It consists of a highly integrated radio frequency chip (RTL8710BX) and an external flash chip, with a built-in Wi-Fi network protocol stack and robust library functions. WR3L also contains a low power-consuming ARM CM4F, a WLAN MAC, a 1T1R WLAN, and the maximum basic frequency of 125 MHz, and is embedded with a 256 KB SRAM, a 2 MB flash, and robust peripheral resources.


WR3L 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 schematic diagram of WR3L.

WR3L Module Datasheet


Built-in low power-consuming 32-bit CPU functioning as an application processor

  • Basic frequency: 125 MHz
  • Operating voltage: 3 V to 3.6 V
  • Peripherals: 7 GPIOs, 2 UARTs, and 1 ADC
  • Wi-Fi connectivity
  • 802.11 b/g/n20/n40
  • Channels 1 to 14@2.4 GHz
  • WEP/WPA/WPA2/WPA2 PSK (AES) security mode
  • Up to +20 dBm output power in 802.11b mode
  • SmartConfig mode (for Android and iOS devices)
  • Passed the CE, FCC, and SRRC certifications
  • Operating temperature: –20°C to +105°C


  • Intelligent building
  • Intelligent home and household appliances
  • Healthcare
  • Industrial wireless control
  • Baby monitor
  • Network camera
  • Intelligent bus

Module interfaces

Dimensions and pin layout

WR3L provides two lines of pins (2 x 8) with a distance of 2 mm between every two pins.

WR3L dimensions: 16±0.35 mm (W)×24±0.35 mm (L) ×3.4±0.15 mm (H) (see the following figure)

WR3L Module Datasheet

Pin Definition

​ Table 2.1 describes the common pins.

No. Symbol I/O Type Function
1 NC / Disconnected to be compatible with other modules
3 CHIP_EN I/O The pin function is disabled by firmware. The user can choose not to connect.
5 GPIOA_14 I/O GPIOA_14, used for hardware PWM
6 GPIOA_15 I/O GPIOA_15, used for hardware PWM
7 GPIOA_0 I/O GPIOA_0, which cannot be pulled up during power-on and can be configured after power-on. It is used for hardware PWM.
8 VD33 P Module power supply pin (3.3 V)
9 GND P Power supply reference ground pin
10 ADC AI ADC port, with the maximum input voltage of 5 V
11 GPIOA_29 I/O UART_Log_RXD (used for printing the internal information of the module)
12 GPIOA_30 I/O UART_Log_TXD (used for printing the internal information of the module)
13 GPIOA_5 I/O GPIOA_5, used for hardware PWM
14 GPIOA_12 I/O GPIOA_12, used for hardware PWM
15 RXD I/O UART0_RXD (user’s serial port)
16 TXD I/O UART0_TXD (user’s serial port)

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

Electrical parameters

Absolute electrical parameters

​ Table 3.1 Absolute parameters

Parameter Description Minimum value Maximum value Unit
Ts Storage temperature –40 125 °C
VDD Power-supply voltage –0.3 3.6 V
ESD voltage (human body model) TAMB – 25°C - 2 kV
ESD voltage (machine model) TAMB – 25°C - 0.5 kV

Electrical conditions

​ Table 3.2 Normal electrical conditions

Parameter Description Minimum value Typical value Maximum value Unit
Ta Operating temperature –20 - 105 °C
VDD Operating voltage 3.0 - 3.6 V
VIL I/O low-level input –0.3 - VDD x 0.25 V
VIH I/O high-level input VDD x 0.75 - 3.6 V
VOL I/O low-level output - - VDD x 0.1 V
VOH I/O high-level output VDD x 0.8 - VDD V
Imax I/O drive current - - 16 mA
Cpad Input pin capacitance - 2 - pF

Wi-Fi TX power consumption

​ Table 3.3 TX power during constant emission

Symbol Mode Rate Typical value Unit
IRF 11b 11 Mbit/s 17 dBm 287 mA
IRF 11b 11 Mbit/s 18 dBm 295 mA
IRF 11g 54 Mbit/s 15 dBm 255 mA
IRF 11g 54 Mbit/s 17.5 dBm 267 mA
IRF 11n BW20 MCS7 13 dBm 244 mA
IRF 11n BW20 MCS7 16.5 dBm 257 mA
IRF 11n BW40 MCS7 13 dBm 220 mA
IRF 11n BW40 MCS7 16.5 dBm 230 mA

Wi-Fi RX power consumption

​ Table 3.4 RX power during constant receiving

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

Power consumption in working mode

​ Table 3.5 Operating current

Working mode Working status (Ta = 25°C) Typical value Maximum value Unit
EZ mode The module is in the EZ state and the Wi-Fi indicator fast flashes. 115 125 mA
Idle mode The module is in the connected state and the Wi-Fi indicator is steady on. 60 209 mA
Working mode The module is in the connected state and the Wi-Fi indicator is steady on. 118 198 mA
Disconnection mode The module is in the disconnected state and the Wi-Fi indicator is steady off. 34 192 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 band 2.400 GHz to 2.4835 GHz
Wi-Fi standard IEEE 802.11b/g/n (channels 1 to 14)
Data transmission rate 11b: 1, 2, 5.5, 11 (Mbit/s)
11g: 6, 9, 12, 18, 24, 36, 48, 54 (Mbit/s)
11n: HT20 MCS0 to MCS7
11n: HT40 MCS0 to MCS7
Antenna type Onboard PCB antenna

Wi-Fi output performance

​ Table 4.2 TX power during constant emission

Parameter Minimum value Typical value Maximum value Unit
RF average output power, 802.11b CCK mode 11 Mbit/s - 17.5 - dBm
RF average output power, 802.11g OFDM mode 54 Mbit/s - 14.5 - dBm
RF average output power, 802.11n OFDM mode MCS7 - 13.5 - dBm
Frequency error –20 - 20 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 11 Mbit/s - –91 - dBm
PER < 10%, RX sensitivity, 802.11g OFDM mode 54 Mbit/s - –75 - dBm
PER < 10%, RX sensitivity, 802.11n OFDM mode MCS7 - –72 - dBm

Antenna information

Antenna types

​ Only the onboard PCB antenna is used.

Antenna Interference Reduction

​ When using an onboard PCB antenna on a Wi-Fi module, make sure that the antenna on the module is at least 15 mm away from other metal parts to ensure optimal wireless performance.

Packaging information and production instructions

Mechanical dimensions

WR3L Module Datasheet

Recommended PCB encapsulation

Figure 6.3 Pin mapping
WR3L Module Datasheet

Figure 6.4 Module PBC Encapsulation

WR3L Module Datasheet

Pin header specifications

​ WR3L provides models with and without pin headers, respectively, which can be used as required.

The following figure shows the pin header dimensions and recommended layout (unit: mm).
WR3L Module Datasheet

Production instructions

  1. For the modules that can be packaged with the SMT or in an in-line way, you can select either of them according to the PCB design solutions of customers. If a PCB is designed to be SMT-packaged, package the module with the SMT. If a PCB is designed to be in-line-packaged, package the module in an in-line way. After being unpacked, the module must be soldered within 24 hours. Otherwise, it needs to be put into the drying cupboard where the relative humidity is not greater than 10%; or it needs to be packaged again under vacuum and the exposure time needs to be recorded (the total exposure time cannot exceed 168 hours).
    • (SMT process) SMT devices:
      • Mounter
      • SPI
      • Reflow soldering machine
      • Thermal profiler
      • Automated optical inspection (AOI) equipment
    • (Wave soldering process) Wave soldering devices
      • Wave soldering equipment
      • Wave soldering fixture
      • Constant-temperature soldering iron
      • Tin bar, tin wire and flux
      • Thermal profiler
    • Baking devices:
      • Cabinet oven
      • Anti-electrostatic and heat-resistant trays
      • Anti-electrostatic and heat-resistant gloves
  2. Storage conditions for a delivered module:
    • The moisture-proof bag must be placed in an environment in which 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.

    • There is a humidity indicator card (HIC) in the packaging bag.

      WR3L Module Datasheet

  3. The module needs to be baked in the following cases:
    • The packaging bag is damaged before unpacking.
    • There is no humidity indicator card (HIC) in the packaging bag.
    • After unpacking, circles of 10% and above on the HIC become pink.
    • The total exposure time has lasted for over 168 hours since unpacking.
    • More than 12 months have passed since the sealing of the bag.
  4. Baking settings:
    • Temperature: 60°C and ≤ 5% RH for reel package and 125°C and ≤5% RH for tray package (please use the heat-resistant tray rather than plastic container)
    • Time: 48 hours for reel package and 12 hours for tray package
    • Alarm temperature: 65°C for reel package and 135°C for tray package
    • Production-ready temperature after natural cooling: < 36°C
    • Re-baking situation: If a module remains unused for over 168 hours after being baked, it needs to be baked again.
    • If a batch of modules is not baked within 168 hours, do not use the reflow soldering or wave soldering to solder them. Because these modules are Level-3 moisture-sensitive devices, they are very likely to get damp when exposed beyond the allowable time. In this case, if they are soldered at high temperatures, it may result in device failure or poor soldering.
  5. In the whole production process, take electrostatic discharge (ESD) protective measures.
  6. 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

Select a proper soldering manner according to the process. For the SMT process, please refer to the recommended oven temperature curve of reflow soldering. For the wave soldering process, please refer to the recommended oven temperature curve of wave soldering. There are some differences between the set temperatures and the actual temperatures. All the temperatures shown in this module datasheet are obtained through actual measurements.

Manner 1: SMT process (Recommended oven temperature curve of reflow soldering)

Set oven temperatures according to the following curve.

WR3L 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.

Manner 2: Wave soldering process (Oven temperature curve of wave soldering)

Set oven temperatures according to the following temperature curve of wave soldering. The peak temperature is 260°C±5°C.

WR3L Module Datasheet
Suggestions on oven temperature curve of wave soldering Suggestions on manual soldering temperature
Preheat temperature 80 to 130 °C Soldering temperature 360±20°C
Preheat time 75 to 100s Soldering time <3s/point
Peak contact time 3 to 5s NA NA
Temperature of tin cylinder 260±5°C NA NA
Ramp-up slope ≤2°C/s NA NA
Ramp-down slope ≤6°C/s NA NA

Storage conditions

WR3L Module Datasheet

MOQ and packaging information

Product Number MOQ (pcs) Shipping packaging method The number of modules per reel (pcs) The number of reels per carton (reel)
WR3L 3600 Tape reel 900 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 to 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 operate 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-WR3L. The end product must be labeled in a visible area with the following: “Contains Transmitter Module FCC ID: 2ANDL-WR3L”.

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

WR3L Module Datasheet

Hereby, Hangzhou Tuya Information Technology Co., Ltd declares that this module product complies 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.

WR3L Module Datasheet

This product must not be disposed of as normal household waste, following 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 a municipal recycling collection point.

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