How to Use STM32WB55RG: Examples, Pinouts, and Specs

The STM32WB55RG is a dual-core microcontroller developed by STMicroelectronics. It features an Arm Cortex-M4 core for high-performance application processing and an Arm Cortex-M0+ core dedicated to managing low-power tasks. This microcontroller is designed for IoT applications, offering integrated Bluetooth 5.0 connectivity, advanced security features, and a wide range of peripherals. Its versatility makes it suitable for applications such as smart home devices, wearable technology, industrial automation, and medical devices.

The STM32WB55RG microcontroller is packed with features that make it a powerful and flexible choice for embedded systems. Below are its key technical specifications:

• Core Architecture: Dual-core (Arm Cortex-M4 @ 64 MHz and Arm Cortex-M0+ @ 32 MHz)
• Flash Memory: 1 MB
• RAM: 256 KB
• Bluetooth Version: Bluetooth 5.0 (LE)
• Operating Voltage: 1.71 V to 3.6 V
• Operating Temperature: -40°C to +85°C
• Package: LQFP64 (64-pin)

• Communication Interfaces:
  • 1x USB 2.0 Full-Speed
  • 2x SPI/I2S
  • 3x I2C
  • 1x CAN
  • 1x USART and 2x UART
• Timers:
  • 1x Advanced Timer
  • 4x General-Purpose Timers
  • 2x Low-Power Timers
• Analog:
  • 1x 12-bit ADC (up to 16 channels)
  • 1x 12-bit DAC
• GPIOs: Up to 46 configurable GPIO pins
• Security Features:
  • Secure firmware update
  • Hardware encryption (AES, RSA, SHA)
  • True Random Number Generator (TRNG)

The STM32WB55RG comes in a 64-pin LQFP package. Below is a table summarizing the key pin functions:

For the complete pinout, refer to the STM32WB55RG datasheet.

1. Power Supply: Ensure the microcontroller is powered within its operating voltage range (1.71 V to 3.6 V). Use decoupling capacitors (e.g., 0.1 µF) close to the VDD and VSS pins to stabilize the power supply.
2. Clock Configuration: The STM32WB55RG supports internal and external clock sources. For precise timing, connect an external crystal oscillator to the HSE pins.
3. Programming: Use the SWD (Serial Wire Debug) interface for programming and debugging. Tools like ST-Link or J-Link are commonly used.
4. Bluetooth Configuration: The integrated Bluetooth 5.0 stack can be configured using the STM32CubeWB software package. Ensure the RF antenna is properly connected to the RF pin for optimal performance.
5. Peripheral Setup: Configure the desired peripherals (e.g., UART, SPI, I2C) using STM32CubeMX or directly in your firmware.

• Power Management: Utilize the low-power modes (e.g., Stop, Standby) of the Cortex-M0+ core to optimize energy consumption in battery-powered applications.
• GPIO Configuration: Set unused GPIO pins to analog mode to reduce power leakage.
• Firmware Updates: Use the secure firmware update feature to ensure the integrity of your application.

Below is an example of using the STM32WB55RG to send data to an Arduino UNO via UART:

// STM32WB55RG UART Example
// This code configures UART2 on the STM32WB55RG to send "Hello, Arduino!" 
// to an Arduino UNO. Ensure the TX pin of STM32WB55RG is connected to the 
// RX pin of the Arduino UNO.

#include "stm32wbxx_hal.h"

UART_HandleTypeDef huart2;

void SystemClock_Config(void);
void MX_USART2_UART_Init(void);

int main(void) {
    HAL_Init(); // Initialize the HAL Library
    SystemClock_Config(); // Configure the system clock
    MX_USART2_UART_Init(); // Initialize UART2

    char message[] = "Hello, Arduino!\r\n";

    while (1) {
        HAL_UART_Transmit(&huart2, (uint8_t *)message, sizeof(message) - 1, HAL_MAX_DELAY);
        HAL_Delay(1000); // Send message every 1 second
    }
}

void MX_USART2_UART_Init(void) {
    huart2.Instance = USART2;
    huart2.Init.BaudRate = 9600;
    huart2.Init.WordLength = UART_WORDLENGTH_8B;
    huart2.Init.StopBits = UART_STOPBITS_1;
    huart2.Init.Parity = UART_PARITY_NONE;
    huart2.Init.Mode = UART_MODE_TX_RX;
    huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
    huart2.Init.OverSampling = UART_OVERSAMPLING_16;
    HAL_UART_Init(&huart2);
}

// Add SystemClock_Config() function here as per your clock setup

1. Microcontroller Not Responding:

   • Cause: Incorrect power supply or missing decoupling capacitors.
   • Solution: Verify the power supply voltage and add decoupling capacitors near the VDD pins.

2. Bluetooth Connectivity Issues:

   • Cause: Improper antenna connection or incorrect Bluetooth stack configuration.
   • Solution: Check the RF antenna connection and ensure the Bluetooth stack is properly initialized in the firmware.

3. Programming Failure:

   • Cause: Faulty SWD connection or incorrect programming tool settings.
   • Solution: Verify the SWD connections and ensure the programming tool is configured for the STM32WB55RG.

1. Can I use the STM32WB55RG without Bluetooth?

   • Yes, the Bluetooth functionality is optional. You can use the microcontroller for general-purpose applications without enabling Bluetooth.

2. What development tools are recommended?

   • Use STM32CubeIDE for development and STM32CubeMX for peripheral configuration. For debugging, ST-Link or J-Link is recommended.

3. How do I update the firmware securely?

   • Use the secure firmware update feature provided by STMicroelectronics. Refer to the STM32WB55RG reference manual for detailed instructions.

By following this documentation, you can effectively integrate the STM32WB55RG into your projects and troubleshoot common issues. For more details, consult the official datasheet and reference manual from STMicroelectronics.