Wi-Fi Module Introduction — WR3L

1. Product Overview

​ WR3L is a low power-consuming 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.

1.1 Features

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

  • Basic frequency: 125 MHz

Working voltage: 3 V to 3.6 V

Peripherals: seven GPIOs, two UARTs, and one ADC

Wi-Fi connectivity

  • 802.11 b/g/n20/n40
  • Channels 1 to 14@2.4 GHz
  • WPA/WPA2 security mode
  • Up to +20 dBm output power in 802.11b mode
  • SmartConfig mode (for Android and iOS devices)
  • Passing the CE, FCC, and SRRC certification
  • Working temperature: –20°C to +105°C

1.2 Major Application Fields

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

2. Module Interfaces

2.1 Dimensions and Pin Layout

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

WR3L dimensions: 16 mm (W) x 24 mm (L) x 3.3 mm (H) (see figure 2.1)

2.2 Pin Definition

​ Table 2.1 describes the common pins.

No. Symbol I/O Type Function
1 NC / Disconnected to be compatible with other modules
2 GPIOA_22 I/O GPIOA_22
3 CHIP_EN I/O External enablement reset pin (valid at low level)
4 GPIOA_19 I/O GPIOA_19
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.

3. Electrical Parameters

3.1 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
Static electricity voltage (human model) TAMB – 25°C - 2 kV
Static electricity voltage (machine model) TAMB – 25°C - 0.5 kV

3.2 Electrical Conditions

​ Table 3.2 Normal electrical conditions

Parameter Description Minimum Value Typical Value Maximum Value Unit
Ta Working temperature –20 - 105 °C
VDD Working 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

3.3 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

3.4 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

###3.5 Power Consumption in Working Mode

​ Table 3.5 Module working 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.

4. RF Features

4.1 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

4.2 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

4.3 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

5. Antenna Information

5.1 Antenna Types

​ Only the onboard PCB antenna is used.

5.2 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.

6. Packaging Information and Production Instructions

6.1 Mechanical Dimensions

​ Figure 6.1 Module dimensions

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6.3 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).

6.4 Production Instructions

Storage conditions of a delivered module are as follows:

  1. The anti-moisture bag must be 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.

Note:

  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.

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Consult

400-881-8611