Nucleo WBA55CG

✅ Hubble Compatible - This board is fully compatible with Hubble Network

Overview

The Nucleo WBA55CG is STMicroelectronics’ development board for the STM32WBA55 wireless microcontroller. Built on the Arm Cortex-M33 core with TrustZone security, it is the successor to the Nucleo WB55RG and represents ST’s current-generation BLE platform. The single-core architecture simplifies firmware development compared to the WB55’s dual-core design — you no longer need to flash a separate wireless coprocessor binary before Bluetooth works.

Quick Specifications

Specification	Details
Manufacturer	STMicroelectronics
SoC	STM32WBA55CG
CPU	ARM Cortex-M33 @ 100 MHz with TrustZone, MPU, DSP, FPU
RAM	128 KB SRAM (64 KB with parity check)
Flash	1 MB with ECC
Bluetooth	BLE 5.3, IEEE 802.15.4 (Thread, Zigbee, Matter)
Zephyr Board ID	`nucleo_wba55cg`

Key Features

Arm Cortex-M33 with TrustZone for hardware-enforced security (SESIP3 / PSA L3 capable)
Bluetooth Low Energy 5.3 with extended advertising and direction finding
IEEE 802.15.4 radio (Thread, Zigbee, Matter)
Single-core architecture with integrated BLE stack (no separate M0+ coprocessor binary required)
On-board ST-LINK/V3 debugger/programmer
USB Micro-B connector for power and debugging
Arduino Uno R3 compatible headers and ST morpho headers
3 user LEDs and 3 user buttons
Ultra-low-power modes (down to 140 nA standby)
Integrated balun to reduce BOM for RF design
RX sensitivity: -96 dBm at 1 Mbps BLE
Programmable TX power: up to +10 dBm in 1 dB steps

Upgrading from Nucleo WB55RG

If you’re currently using the Nucleo WB55RG, the WBA55CG offers several advantages:

Feature	Nucleo WB55RG	Nucleo WBA55CG
Core	Cortex-M4 @ 64 MHz + Cortex-M0+	Cortex-M33 @ 100 MHz
BLE Version	5.0	5.3
Security	Software-based	Hardware TrustZone
Architecture	Dual-core (requires separate M0+ binary)	Single-core (integrated BLE stack)
Protocols	BLE, 802.15.4	BLE, 802.15.4, Matter
Debugger	ST-LINK/V2-1	ST-LINK/V3
Standby current	600 nA	140 nA

Getting Started with Hubble

Prerequisites

Before you begin, ensure you have:

Nucleo WBA55CG board
USB Micro-B cable (data-capable)
Zephyr development environment installed
Hubble Network account

Important: BLE and IEEE 802.15.4 support require binary blobs from the STM32 HAL. Run west blobs fetch hal_stm32 before building BLE applications.

Build and Flash

Follow the Hubble Zephyr Quick Start Guide to integrate Hubble Network into your project.

Once your environment is configured, build and flash the Hubble BLE Network sample:

# Fetch required BLE binary blobs
west blobs fetch hal_stm32

# Build for Nucleo WBA55CG
cd ~/hubblenetwork-workspace/
west build -p -b nucleo_wba55cg modules/lib/hubblenetwork-sdk/samples/zephyr/ble-network

# Flash to board (uses STM32CubeProgrammer by default)
west flash

Verify Connection

Connect to the serial console to verify your board is communicating with Hubble:

# Linux/macOS
minicom -D /dev/ttyACM0 -b 115200

# Windows (use PuTTY or similar)
# Connect to COMx at 115200 baud

You should see output indicating successful Hubble Network initialization.

Pinout Reference

LEDs

LD1: PB4

Buttons

USER_PB: PC13

UART Console (USART1)

TX: PB12 (connected to ST-LINK VCP)
RX: PA8 (connected to ST-LINK VCP)
Baud Rate: 115200

I2C

I2C1_SCL: PB2
I2C1_SDA: PB1

SPI (Arduino header)

SPI1_NSS: PA12
SPI1_SCK: PB4
SPI1_MISO: PB3
SPI1_MOSI: PA15

Power Considerations

The Nucleo WBA55CG provides multiple power options:

USB Power: Connect via USB Micro-B (most common for development)
External 5V: E5V pin
External 3.3V: 3V3 pin

Power Consumption (from datasheet):

Standby: 140 nA (16 wake-up pins)
Standby with RTC: 200 nA
Standby with 64 KB SRAM: 2.4 µA
Stop mode with 64 KB SRAM: 16.3 µA
Run mode: 45 µA/MHz at 3.3 V
Radio RX: 7.4 mA
Radio TX at 0 dBm: 10.6 mA

The STM32WBA55 supports both LDO and SMPS power regulation. The Nucleo WBA55CG uses the SMPS variant for improved power efficiency.

Troubleshooting

Board not detected

Ensure USB cable supports data (not charging-only)
Try a different USB port
Update ST-LINK firmware using STM32CubeProgrammer

Flash errors

Press the black RESET button and try again
Check that no other debugger software (STM32CubeIDE) is running
STM32CubeProgrammer is the default flash runner; OpenOCD also supported via west flash --runner openocd

Bluetooth not working

Ensure you have fetched BLE binary blobs: west blobs fetch hal_stm32
Unlike the WB55RG, the WBA55CG does not require a separate wireless coprocessor binary
Verify your Zephyr build includes BLE support (CONFIG_BT=y in prj.conf)

Serial output issues

Verify baud rate is set to 115200
ST-LINK Virtual COM Port should appear as /dev/ttyACM0
Install ST-LINK USB drivers if needed

Resources

Official Documentation

Zephyr Documentation

Hubble Network

Purchase

Next Steps

Nucleo WB55RG

Previous-generation ST BLE board

Guides

BLE tutorials and best practices

Hubble Docs

Complete API reference

Nucleo WB55RG