WR2 Module Datasheet

WR2 is a low-power embedded Wi-Fi module that Tuya has developed. It consists of a highly integrated wireless RF chip (RTL8710BN) and an external flash chip, with an embedded Wi-Fi network protocol stack and varied library functions.

Overview

With the maximum CPU clock rate of 125 MHz, WR2 also contains a low-power ARM CM4F, a WLAN MAC, a 1T1R WLAN module, 256-KB static random-access memory (SRAM), 2-MB flash memory, and extensive peripherals.

WR2 is an RTOS platform that integrates all function libraries of the Wi-Fi MAC and TCP/IP protocols. You can develop embedded Wi-Fi products as required. The structural diagram of WR2 is shown in the following figure:

Features

• Embedded low-power 32-bit CPU, which can also function as an application processor
• Main clock rate: 125 MHz
• Operating voltage: 3.0 to 3.6 V
• Peripherals: 5 GPIOs, 1 universal asynchronous receiver/transmitters (UART), and 1 analog to digital converter (ADC)
• Wi-Fi connectivity
• 802.11 B/G/N20/N40
  • Channels 1 to 14 at 2.4 GHz
  • Support WEP/WPA/WPA2/WPA2 PSK (AES) security mode
  • Output power of +20 dBm in 802.11b mode
  • Support SmartConfig functions for Android and iOS devices
  • Onboard PCB antenna
  • Passed CE, FCC, and SRRC certification
  • Operating temperature: -20℃ to 85℃

Applications

• Intelligent building
• Smart household and home appliances
• Medical health care
• Industrial wireless control
• Baby monitor
• Network camera
• Intelligent bus

Module interfaces

Dimensions and footprint

WR2 has two lines of pins with a 2.0mm pin spacing. Each row has 9 pins.

The dimensions of WR2 are 15±0.35 mm (W)×18 ±0.35 mm (L) ×4.9±0.15 mm (H). (In the bottom view, the height of the device is 1.5 mm). The diagram of dimensions of WR2:

Pin definition

Definitions of common pins are shown in the following table:

Pin number	Symbol	I/O type	Function
1	VD33	P	Power supply pin (3.3V)
2	GPIOA_12	I/O	GPIOA_12, a universal GPIO, hardware PWM, IC Pin 17
3	GND	P	Power supply reference ground
4	GPIOA_0	I/O	GPIOA_0, which cannot be pulled high when powered on, and which can be configured with any level after being enabled, hardware PWM, IC Pin 16
5	GPIOA_18	I/O	UART0_RXD (user-side serial interface)
6	GPIOA_5	I/O	GPIOA_5, a universal GPIO, hardware PWM, IC Pin 28
7	GPIOA_23	I/O	UART0_TXD (user-side serial interface)
8	ADC	AI	ADC port, the maximum input voltage is 5V
9	GPIOA_14	I/O	GPIOA_14, a universal GPIO, hardware PWM, IC Pin 13
10	CHIP_EN	I/O	When software disables the function, connection by a user fails
11	GPIOA_15	I/O	GPIOA_15, a universal GPIO, hardware PWM, IC Pin 14

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

Electrical parameters

Absolute electrical parameters

Absolute parameters:

Parameter	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

Normal working conditions:

Parameter	Description	Minimum value	Typical Value	Maximum Value	Unit
Ta	Operating temperature	-20	-	85	℃
VDD	Operating voltage	3.0	-	3.6	V
VIL	IO low level input	-0.3	-	VDD*0.25	V
VIH	IO high level input	VDD*0.75	-	3.6	V
VOL	IO low level output	-	-	VDD*0.1	V
VOH	IO high level output	VDD*0.8	-	VDD	V
Imax	IO drive current	-	-	16	mA
Cpad	Input pin capacitance	-	2	-	pF

Wi-Fi transmission power consumption

TX power consumption:

Working status	Mode	Rate	Transmit power/Receive	Average value	Peak value (Typical value)	Unit
Transmit	11 b	11 Mbps	+17 dBm	287	367	mA
Transmit	11 b	11 Mbps	+18 dBm	295	382	mA
Transmit	11 g	54 Mbps	+15 dBm	255	406	mA
Transmit	11 g	54 Mbps	+17.5 dBm	267	428	mA
Transmit	11n-HT20	MCS 7	13 dBm	244	395	mA
Transmit	11n-HT20	MCS 7	16.5 dBm	257	422	mA
Transmit	11n-HT40	MCS 7	13 dBm	220	393	mA
Transmit	11n-HT40	MCS 7	16.5 dBm	230	420	mA

Wi-Fi receiving power consumption

RX power consumption:

Symbol	Mode	Typical value	Unit
IRF	CPU Sleep	90	mA
IRF	CPU Active	120	mA

Power consumption in working mode

Operating current of the module:

Working mode	Working status, Ta = 25°C	Average value	Peak value (Typical value)	Unit
Quick connection network state	The module is in the fast network connection state and the Wi-Fi indicator always flashes	115	376	mA
Hotspot network configuration state	The module is in the hotspot network configuration state and the Wi-Fi indicator always flashes slowly	60	386	mA
Network connection operation state	The module is connected to the network and the Wi-Fi indicator is always on	105	389	mA
Disconnected state	The module is disconnected and the Wi-Fi indicator is dark	45	381	mA

Note: The peak value lasts about 5μs.

The above parameters may vary with different firmware functions.

RF features

Basic RF features

Basic RF features:

Parameter	Description
Frequency range	2.400 to 2.4835 GHz
Wi-Fi standard	IEEE 802.11 b/g/n (channels 1 to 14)
Data transmission rate	11b: 1, 2, 5.5, 11 (Mbps) 11g: 6, 9, 12, 18, 24, 36, 48, 54 (Mbps) 11n: HT20 MCS 0 to 7
Antenna type	Onboard PCB antenna

Wi-Fi output power

TX power:

Parameter	Minimum value	Typical value	Maximum value	Unit
Average RF output power, 802.11b CCK Mode	11M	-	17.5	-
Average RF output power, 802.11g OFDM Mode 54M	-	14.5	-	dBm
Average RF output power, 802.11n OFDM Mode	MCS7	-	13.5	-
Frequency error		-10	-	10

Wi-Fi receiving sensitivity

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

Antenna type

WB8P uses only an onboard PCB antenna.

Antenna interference reduction

To ensure optimal Wi-Fi performance when the Wi-Fi module uses an onboard PCB antenna, it is recommended that the antenna be at least 15 mm away from other metal parts.

Packaging information and production instructions

Mechanical dimensions

The mechanical dimensions of the PCB of WR2 are 15±0.35 mm (W)×18±0.35 mm (L) ×0.8±0.1 mm (H).

The diagram of mechanical dimensions of WR2:

Recommended PCB layout

The schematic diagram of WR2 shows how pins correspond to each other:

Production instructions

1. For the Tuya in-line module, wave soldering is most preferred and manual soldering is less preferred. After being unpacked, the module 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 record the exposure time (the total exposure time cannot exceed 168 hours).

2. Wave soldering devices and materials:

   • Wave soldering equipment
   • Wave soldering fixture
   • Constant-temperature soldering iron
   • Tin bar, tin wire, and flux
   • Thermal profiler

3. Baking devices:

   • Cabinet oven
   • Anti-electrostatic and heat-resistant trays
   • Anti-electrostatic and heat-resistant gloves

4. 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.

5. Baking settings:

   • Temperature: 40°C and ≤ 5% RH for reel package and 125°C and ≤5% RH for tray package (please use the heat-resistant tray rather than a plastic container)
   • Time: 168 hours for reel package and 12 hours for tray package
   • Alarm temperature: 50°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 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.

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

7. To guarantee the quality of products, you must pay attention to the following items: The amount of soldering flux, the height of the wave peak, whether the tin slag and copper content in the wave soldering tank exceed standards, whether the window and thickness of the wave soldering fixture are appropriate, and whether the wave soldering oven temperature curve is appropriate.

Recommended oven temperature curve and temperature

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

Recommended soldering temperature:

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

Storage conditions for a delivered module:

• The moisture-proof bag is 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.

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

  

  

MOQ and packaging information

Product model	MOQ (pcs)	Shipping packaging method	The number of modules per reel	The number of reels per carton
WR2	2800	Tape reel	700	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-WR2. The end product must be labeled in a visible area with the following: “Contains Transmitter Module FCC ID: 2ANDL-WR2”.

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

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.

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.