Wi-Fi & Bluetooth LE ST (G07) (WBRU) Board

This multifunctional development board comes with a WBRU Wi-Fi and Bluetooth Low Energy (LE) combo module and an STM32G070 microcontroller (MCU) from STMicroelectronics. It can work with circuit modules or boards to help you prototype ideas and evaluate solutions.

Applications

• This development board applies to most custom solutions developed with the MCU SDK. You can use it to build Wi-Fi projects where the network modules communicate with the MCU through the serial protocol.
• Develop with the board to build your IoT projects easily and fast.
• You can use this board for different development purposes.
  • Embedded program development and debugging
  • App development and debugging
  • Creating connected devices that can be controlled with a mobile phone
  • Getting started with IoT development and learning how the Wi-Fi-based control system works

Components

The development board is integrated with Tuya’s proprietary high-performance WBRU Wi-Fi and Bluetooth LE combo module and STM32G070 MCU from STMicroelectronics. It has onboard MCU reset buttons, LED, power port, and a USB-to-serial chip.
For more information, see the WBRU Module Datasheet.
For more information, see Wi-Fi General Solution.

I/O port and pin description

• 1: Micro-USB: Input 5V DC voltage and provide one extended serial port.

• 2: Button (RST): Reset the STM32G070 MCU. Press the button to output low level signals.

• 3: LED indicator: Indicate the power state when the board is powered via the micro-USB connection.

• 4: Power selection jumper: Use a jumper cap to switch the power supply between the USB connection and external power supply.

• 5: USB to UART jumper: Use a jumper cap on PA9 and PA10 to connect to the USB-to-serial chip.

• 6: UART selection jumper: Use a jumper cap on PA2 and PA3 to connect the MCU to the WBRU module.

• 7: LED indicator: When PC6 outputs high, the LED is on.

• 8: External battery pin header: Connect a button cell to the positive (+) and negative (-) terminals for verifying low power mode.

  Pin description

  No.	Symbol	Description	Alternate functions
  1	NC	Leave it floating.	-
  2	NC	Leave it floating.	-
  3	RST	Reset the STM32G070 MCU. Active low.	-
  4	3.3V	3.3V power pin.	-
  5	5V	5V power pin.	-
  6	GND	Ground pin.	-
  7	GND	Ground pin.	-
  8	NC	Leave it floating.	-
  9	PA0	I/O	SPI2_SCK, USART2_CTS, USART4_TX, ADC_IN0, TAMP_IN2, and WKUP1
  10	PA1	I/O	SPI1_SCK/I2S1_CK, USART2_RTS_DE_CK, USART4_RX, TIM15_CH1N, I2C1_SMBA, EVENTOUT, and ADC_IN1
  11	PA4	I/O	SPI1_NSS/I2S1_WS, SPI2_MOSI, TIM14_CH1, EVENTOUT, ADC_IN4, and RTC_OUT2
  12	PA5	I/O	SPI1_SCK/I2S1_CK, USART3_TX, EVENTOUT, and ADC_IN5
  13	PA6	I/O	SPI1_MISO/I2S1_MCK, TIM3_CH1, TIM1_BKIN, USART3_CTS, TIM16_CH1, and ADC_IN6
  14	PA7	I/O	SPI1_MOSI/I2S1_SD, TIM3_CH2, TIM1_CH1N, TIM14_CH1, IM17_CH1, and ADC_IN7
  15	PB11	I/O	SPI2_MOSI, USART3_RX, I2C2_SDA, and ADC_IN15
  16	PB10	I/O	USART3_TX, SPI2_SCK, I2C2_SCL, and ADC_IN11
  17	PC13	I/O	TIM1_BKIN, TAMP_IN1,RTC_TS, RTC_OUT1, and WKUP2
  18	PB9	I/O	IR_OUT, TIM17_CH1, USART3_RX, SPI2_NSS, I2C1_SDA, and EVENTOUT
  19	PA15	I/O	SPI1_NSS/I2S1_WS, USART2_RX, USART4_RTS_DE_CK, USART3_RTS_DE_CK, and EVENTOUT
  20	PD2	I/O	USART3_RTS_DE_CK, TIM3_ETR, and TIM1_CH1N
  21	PB5	I/O	SPI1_MOSI/I2S1_SD, TIM3_CH2, TIM16_BKIN, I2C1_SMBA, and WKUP6
  22	PA8	I/O	MCO, SPI2_NSS, TIM1_CH1, and EVENTOUT
  23	PA11	I/O	SPI1_MISO/I2S1_MCK, USART1_CTS, TIM1_CH4, TIM1_BKIN2, and I2C2_SCL
  24	PA12	I/O	SPI1_MOSI/I2S1_SD, USART1_RTS_DE_CK, TIM1_ETR, I2S_CKIN, and I2C2_SDA
  25	PB12	I/O	SPI2_NSS, TIM1_BKIN, TIM15_BKIN, EVENTOUT, and ADC_IN16
  26	PB15	I/O	SPI2_MOSI, TIM1_CH3N, TIM15_CH1N, TIM15_CH2, EVENTOUT, and RTC_REFIN
  27	PB14	I/O	SPI2_MISO, TIM1_CH2N, USART3_RTS_DE_CK, TIM15_CH1, I2C2_SDA, and EVENTOUT
  28	PB13	I/O	SPI2_SCK, TIM1_CH1N, USART3_CTS, TIM15_CH1N, I2C2_SCL, and EVENTOUT
  29	GND	Ground pin.	-
  30	VCCA	ADC power ground.	-
  31	PB7	I/O	USART1_RX, SPI2_MOSI, TIM17_CH1N, USART4_CTS, I2C1_SDA, and EVENTOUT
  32	PB6	I/O	USART1_TX, TIM1_CH3, TIM16_CH1N, SPI2_MISO, I2C1_SCL, and EVENTOUT

• STM32G070 MCU debugging pins

  No.	Symbol	Description	Alternate functions
  1	3.3V	3.3V power pin.	-
  2	GND	Ground pin.	-
  3	SWC	The serial wire debug port (SW-DP), SWCLK	PA14, BOOT0, USART2_TX, and EVENTOUT
  4	SWD	The serial wire debug port (SW-DP), SWDIO	PA13, IR_OUT, and EVENTOUT

• WBRU module debugging pins

  No.	Symbol	Description	Alternate functions
  1	LRX	I/O	GPIOA_15, which can be used as the UART_Log_RXD pin to receive logs.
  2	LTX	I/O	GPIOA_16, which can be used as the UART_Log_TXD pin to send logs.
  3	MA0	I/O	GPIOA_0. Pull-up will trigger the testing mode. It is not recommended to add an external pull-up resistor for this pin.
  4	MEN	The reset pin. Active low.	-
  5	GND	Ground pin.	-
  6	MVC	3.3V power pin on the module.	-

Load-carrying capacity

• When micro-USB inputs 5V DC voltage, the board can supply power to external components.

  Power pin	Rated voltage/maximum current
  VDD	5V/0.4A
  VCC	3.3V/0.4A

  The micro-USB input port is connected to a 5V/0.5A resettable fuse in series. The total supply current and output current of the development board cannot exceed 0.5A.

• Characteristics of the output voltage of 3.3V

  Output current	0A	0.15A	0.3A	0.45A
  Output voltage	3.34V	3.36V	3.37V	3.37V

  We tested the voltage under the condition that there is no output voltage on the micro-USB (CN1) terminal.

Schematic diagram and PCB

• The schematic diagram of the board:

  

• The PCB board:

  

Jumper settings

• The board has a built-in USB-to-serial chip. You can use a jumper cap on PA9 and PA10 to connect the MCU to the USB-to-serial chip.

  Pin connection description

  Silkscreen	P2	P3
  MCU pin	PA10	PA9
  USB-to-serial chip	USB-TXD	USB-RXD

• You can use a jumper cap on PA2 and PA3 to connect the MCU to the WBRU module.

  Pin connection description

  Silkscreen	P5	P7
  MCU pin	PA3	PA2
  WBRU module	TX	RX

• You can use a jumper cap to switch the power supply between the USB connection and external power supply. The following table provides the description of pin header P4.

  Silkscreen	Description
  BAT	Place a jumper cap on BAT and 3.3V to supply power via battery.
  3.3V	3.3V power output pin.
  USB	Place a jumper cap on USB and 3.3V to supply power via USB connection.

  The + and - pin headers are used to connect to a CR2450 battery.

Module connection for flashing

For flashing license and firmware, connect pins following the table and figure shown below.

USB-to-serial chip driver

Download the USB-to-serial chip driver for your operating system.

• For Windows
• For Linux

Things to note

• The board has a built-in micro-USB port, so the additional power board is not necessary.
• If you connect the board to a power board, do not use the micro-USB port for voltage input.