CR2S Module Datasheet

Last Updated on : 2024-06-14 03:14:30download

CR2S is a low-power embedded Wi-Fi+Bluetooth module that Tuya has developed. Embedded with the Wi-Fi network protocol stack and rich library functions, it consists of a highly integrated RF chip (W701P-VA2-CG). With the maximum CPU clock rate of 100 MHz, CR2S also contains a low-power Real-M300 (KM4) microcontroller unit (MCU), a WLAN MAC, a 1T1R WLAN, a 4-MB pseudo-static random-access memory (PSRAM), 4-MB flash memory, and rich extensive peripherals.


CR2S is an RTOS platform that integrates all function libraries of the Wi-Fi MAC and TCP/IP. You can develop embedded Wi-Fi products as required.


  • Embedded low-power KM4 MCU, which can also function as an application processor
    Main clock rate: 100 MHz
  • Working voltage: 3.0 to 3.6 V
  • Peripherals: 6 (general-purpose input/output) GPIOs and 1 universal asynchronous receiver/transmitter (UART)
  • Wi-Fi/Bluetooth connectivity
    • 802.11 B/G/N20
    • Channels 1 to 14@2.4 GHz (CH1 to 11 for US/CA and CH1 to 13 for EU/CN)
    • Support Bluetooth (Bluetooth Low Energy) 4.2
    • Support WEP, WPA, WPA2, and WPA2 PSK (AES) security modes
    • MAX EIRP: + 20dBm output power in 802.11b mode
    • Support SmartConfig functions for Android and iOS devices
    • Onboard PCB antenna
    • Passed CE and FCC certifications
    • Working temperature: -20℃ to 85℃


  • Intelligent building
  • Smart household and home appliances
  • Smart socket and light
  • Industrial wireless control
  • Baby monitor
  • Network camera
  • Intelligent bus

Change history

Update date Updated content Version after update
2021-01-28 This is the first release. V1.0.0

Module interfaces

Dimensions and package

CR2S has 2 rows of pins with a spacing of 2 mm.

The CR2S dimensions are 15±0.35 mm (W)×18±0.35 mm (L)× 4.45±0.15 mm (H). The height of the back panel is 1.55 mm. The dimensions of CR2S are as follows:

CR2S Module Datasheet

Pin definition

The definition of interface pins is shown in the following table:

Pin number Symbol I/O type Function
1 3V3 P Power supply pin (3.3V)
2 PA17 I/O GPIOA_17, hardware PWM, IC Pin 38
3 GND P Power supply reference ground
4 PA19 I/O GPIOA_19, hardware PWM, IC Pin 40
5 RX I/O GPIOA_13, UART0_RXD (user serial interface)
6 PA18 I/O GPIOA_18, hardware PWM, IC Pin 39
7 TX I/O GPIOA_14, UART0_TXD (user serial interface)
8 PA4 I/O GPIOA_4, hardware PWM, IC Pin 20
9 PA3 I/O GPIOA_3, hardware PWM, IC Pin 19
10 EN I/O Enabling pin, active at the high level. The module has been pulled to the high level and the user can control the pin externally
11 PA2 I/O GPIOA_2, hardware PWM, IC Pin 18

Note: P indicates a power supply pin and I/O indicates an input/output pin.

Electrical parameters

Absolute electrical parameters

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

Working conditions

Parameter Description Minimum value Typical value Maximum value Unit
Ta Working temperature -20 - 85
VDD Working voltage 3.0 - 3.6 V
VIL I/O low level input - - 0.8 V
VIH I/O high level input 2.0 - - V
VOL I/O low level output - - 0.4
VOH I/O high level output 2.4 - -
Imax I/O drive current - - 16 mA
Cpad Input pin capacitance - 2 - pF

RF power consumption

TX power consumption:

Symbol Mode Power Average value Peak value (Typical value) Unit
IRF 11b 11Mbps 17 dBm 222 256 mA
IRF 11b 11Mbps 18 dBm 237 272 mA
IRF 11g 54Mbps 15 dBm 155 225 mA
IRF 11g 54Mbps 17.5 dBm 173 259 mA
IRF 11n BW20 MCS7 13 dBm 143 203 mA
IRF 11n BW20 MCS7 16.5 dBm 165 244 mA

RX power consumption:

Symbol Mode Average value Peak value (Typical value) Unit
IRF 11B 11M 62 67 mA
IRF 11G 54M 61 68 mA
IRF 11N HT20 MCS7 62 69 mA

Working power consumption

Working mode Working status, TA = 25°C Average value Peak value (Typical value) Unit
Quick network pairing state (EZ) The module is in the fast network pairing state and the Wi-Fi indicator flashes fast 77 331 mA
Idle state The module is connected to the network and the Wi-Fi indicator is always on 68 321 mA
Network connection operation state The module is connected to the network and the Wi-Fi indicator is always on 67 316 mA
Disconnected state The module is disconnected and the Wi-Fi indicator is dark 67 312 mA

RF parameters

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)
Bluetooth standard Bluetooth 4.2
Data transmission rate 11b: 1, 2, 5.5, 11 (Mbps)
Data transmission rate 11g: 6, 9, 12, 18, 24, 36, 48, 54 (Mbps)
Data transmission rate 11n: HT20 MCS0 to 7
Antenna type PCB antenna with a peak gain of 1.7 dBi

TX performance

TX performance

Parameter Minimum value Typical value Maximum value Unit
Average RF output power, 802.11b CCK Mode 1M - 17.5 - dBm
Average RF output power, 802.11g OFDM Mode 54M - 14.5 - dBm
Average RF output power, 802.11n OFDM Mode MCS7 - 13.5 - dBm
Average RF output power, Bluetooth 4.2 1M - 6.5 - dBm
Frequency error -20 - 20 ppm
EVM@802.11b CCK 11 Mbps Mode 17.5 dBm - - -10 dB
EVM@802.11g OFDM 54 Mbps Mode 14.5 dBm - - -29 dB
EVM@802.11n OFDM MCS7 Mode 13.5 dBm - - -30 dB

RX Performance

Parameter Minimum value Typical value Maximum value Unit
PER<8%, RX sensitivity, 802.11b CCK Mode 1M - -97 - dBm
PER<10%, RX sensitivity, 802.11g OFDM Mode 54M - \ -75 - dBm
PER<10%, RX sensitivity, 802.11n OFDM Mode MCS7 - \ -72 - dBm
PER<10%, RX sensitivity, Bluetooth 4.2 1M - \ -93 - dBm

Antenna information

Antenna type

CR2S uses only an onboard PCB antenna with a peak gain of 1.7 dBi.

Antenna interference reduction

To ensure the 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.

Power-on/off sequence

Power-on sequence

The W701P chip has requirements on the power-on sequence. It is recommended that the voltage rises from 0 to 3.3V within 20 ms.
CR2S Module Datasheet

Power-off sequence

CR2S Module Datasheet

Symbol Parameter Minimum value Typical value Maximum value Unit
TPRDY 3.3V ready time 0.6 - 20 ms
CHIP_EN CHIP_EN ready time 0.6 - 20 ms
VBOR BOR occurs after 3.3V is lower than this voltage 2 - - V
TRST The required time that 3.3V is lower than VBOR 1 - - ms

Packaging information and production instructions

Mechanical dimensions

The mechanical dimensions of the PCB of CR2S are 15±0.35 mm (W)×18±0.35 mm (L) ×0.8±0.1 mm (H). The following figure shows the mechanical dimensions of CR2S:

CR2S Module Datasheet

CR2S Module Datasheet

Note: The default dimensional tolerance is ±0.35 mm. If you have specific requirements on dimensions, make them clear in the module datasheet after communication.

Recommended PCB footprint

The following figure is a schematic diagram of CR2S which shows how pins correspond to each other:

CR2S Module Datasheet

The following is the diagram of the packaging of the PCB of CR2S:

CR2S Module Datasheet

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: 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 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.

CR2S Module Datasheet

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.

    CR2S Module Datasheet

    CR2S Module Datasheet

MOQ and packaging information

Product model MOQ (pcs) Shipping packaging method Modules per reel Reels per carton
CR2S 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 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-CR2S. The end product must be labelled in a visible area with the following: “Contains Transmitter Module FCC ID: 2ANDL-CR2S”.

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

CR2S 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

CR2S 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 to the human body.