Introduction to Wi-Fi Module--WR4
Wi-Fi module introduction–WR4
1. 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.
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
Channel 1–firstname.lastname@example.org 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
1.2 Major Application Fields
- Intelligent building
- Intelligent home and household applications
- Health care
- Industrial wireless control
- Baby monitor
- Network camera
- Intelligent bus
2. Module Interfaces
2.1 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
2.2 Pin Definition
Table 2.1 describes the common pins. Table 2.1 WR4 pins
|1||NC||/||NC, not connected|
|2||ADC||AI||ADC interface, with the maximum output power of 5 V|
|3||EN||I/O||External enabled reset pin (active low)|
|6||A_0||I/O||GPIOA_0, which cannot be pulled up during power-on and can be configured after power-on|
|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)|
|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.
3.1 Absolute Electrical Characteristics
Table 3.1 Absolute electrical characteristics
|Parameters||Description||Minimum value||Maximum value||Unit|
|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|
3.2 Electrical conditions
Table 3.2 Normal electrical conditions
|Parameter||Description||Minimum Value||Typical Value||Maximum Value||Unit|
|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|
3.3 Wi-Fi TX Power Consumption
Table 3.3 TX power consumption during constant emission
|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%.
3.4 Wi-Fi RX Power Consumption
Table 3.4 RX power consumption during constant emission
3.5 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.
4. RF Features
4.1 Basic RF Features
Table 4.1,Basic RF features
|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|
4.2 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|
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||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|
5. Antenna Information
5.1 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.
5.2 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.
5.3 U.FL RF connector
Figure 5.2 shows the U.FL RF connector parameters.
6. Packaging Information and Poduction Instructions
6.1 Mechanical Dimensions
6.2 Recommended PCB Encapsulation
6.3 Production Instructions
Storage conditions of a delivered module are as follows:
- The anti-moisture bag is placed in an environment where the temperature is under 30°C and the relative humidity is under 85%.
- The shelf life of a dry-packaged product is six months from the date when the product is packaged and sealed.
- Throughout the production process, each involved operator must wear an electrostatic ring.
- During the operation, strictly protect the module from water and strains.
6.4 Recommended Oven Temperature Profile