NoeticMaze

NoeticMaze is the embedded control and navigation project used for the NUCLEO-F446RE demonstration. The system integrates lidar, IMU, wheel encoders, differential-drive motor control, ICP-based localisation, grid mapping, A* path planning, path following, Bluetooth telemetry, and FreeRTOS task scheduling.

This ZIP contains the source code, header files, generated STM32 configuration files, CMake build files, linker/startup files, and supporting resources required to compile and run the demonstrated system on the NUCLEO-F446RE.

STM32.slam._P2_._compressed_h264_under_10MB.mp4

Target Platform

• Board: NUCLEO-F446RE
• MCU: STM32F446RE / Cortex-M4F
• RTOS: FreeRTOS with CMSIS-RTOS v2 API
• Main build target: NoeticMaze
• Main output files after build: NoeticMaze.elf, NoeticMaze.hex, NoeticMaze.bin

Project Folder Structure

NoeticMaze/
├── App/                         # User application modules
│   ├── algorithmBrain/           # ICP, SLAM/mapping bridge, localisation and re-planning logic
│   ├── global/                   # Shared robot state, global configuration and runtime parameters
│   ├── imu/                      # MPU6500 IMU driver and attitude/yaw processing
│   ├── lidar/                    # Lidar DMA reception, frame decoding and point-cloud buffering
│   ├── motor/                    # Encoder reading, PWM output, motor PID and motion control
│   ├── Planner/                  # 10 cm grid map, A* planner, priority queue and path smoothing
│   └── printf/                   # Debug print, Bluetooth protocol and telemetry support
├── Core/                         # STM32CubeMX generated startup, peripheral init and FreeRTOS tasks
│   ├── Inc/
│   └── Src/
├── Drivers/                      # STM32 HAL, CMSIS and CMSIS-DSP sources/headers
├── Middlewares/                  # FreeRTOS middleware
├── cmake/                        # ARM GCC toolchain and STM32CubeMX CMake integration
├── asset/                        # Wiring image, utility scripts, test resources and demo assets
├── CMakeLists.txt                # Root CMake file for CLion/CMake build
├── CMakePresets.json             # Debug/Release/RelWithDebInfo/MinSizeRel CMake presets
├── NoeticMaze.ioc                # STM32CubeMX project configuration
├── STM32F446XX_FLASH.ld          # Linker script
└── startup_stm32f446xx.s         # STM32 startup assembly file

The root CMakeLists.txt recursively includes all source/header files under App/, links the STM32CubeMX generated code from cmake/stm32cubemx, enables the Cortex-M4F hard-float options, links selected CMSIS-DSP sources, and generates .hex and .bin files after the ELF build.

Custom Modules and Hardware Abstraction Components

• App/lidar: implements UART DMA based lidar byte reception, protocol parsing, 360-degree LidarMap_t construction, kinematic frame filtering, and a FreeRTOS queue-based zero-copy buffer pool.
• App/imu: contains the MPU6500 related driver code and DMP/attitude support used to update yaw and yaw-rate state.
• App/motor: abstracts PWM, encoder feedback, motor PID, yaw-rate control, normal stop and emergency stop behaviour for the differential-drive chassis.
• App/global: provides shared robot-state snapshots, map-to-odom transform state, trimmed-path state, unit conversion helpers, and central configuration constants.
• App/algorithmBrain: converts lidar polar scans into Cartesian point clouds, performs ICP/localisation, maintains the high-resolution map, and triggers planner requests when goals, obstacles, or robot pose drift require re-planning.
• App/Planner: maintains the lower-resolution planner map, runs A* search, applies obstacle/cost handling, smooths the path, and publishes the latest safe path through a global snapshot and FreeRTOS event flag.
• App/printf: provides debug output, Bluetooth packet/protocol support, and telemetry transmission helpers.
• Core and cmake/stm32cubemx: provide the STM32 HAL abstraction for GPIO, DMA, SPI, UART, timers, interrupts, and FreeRTOS task creation.

CLion Build and Flash Configuration

This project is built and flashed from CLion using CMake/Ninja and an ARM embedded GCC toolchain.

Recommended CLion CMake profile:

• Profile: Debug or Release
• Generator: Ninja
• Toolchain: ARM GCC / gcc-arm-none-eabi
• Toolchain file: cmake/gcc-arm-none-eabi.cmake
• Build target: NoeticMaze
• Build directory: cmake-build-debug or the directory selected by the active CMake preset

The repository also includes CMakePresets.json with Debug, Release, RelWithDebInfo, and MinSizeRel presets. In CLion, open the project root, reload CMake, select the required preset/profile, and build the NoeticMaze target.

Recommended CLion download/debug configuration:

• Configuration type: OpenOCD Download & Run
• Name: NoeticMaze
• Target: NoeticMaze
• Executable binary: NoeticMaze
• Debugger: bundled GDB multiarch
• Board config file: board/st_nucleo_f4.cfg
• GDB port: 3333
• Telnet port: 4444
• Download: If updated
• Reset: Init
• Before launch: Build

ST-LINK debug server settings used on the development machine:

• Transport interface: SWD
• Initial speed: 8000 kHz
• ST-LINK GDB server executable: D:\program files2\STM32CubeCLT_1.21.0\STLink-gdb-server\bin\ST-LINK_gdbserver.exe
• STM32CubeProgrammer path: D:\program files2\STM32CubeCLT_1.21.0\STM32CubeProgrammer\bin

Hardware Connections

The wiring reference image is stored at asset/img.png.

IMU

Module pin	NUCLEO-F446RE pin	Function
VCC	3.3V	Power
GND	GND	Ground
SCL	PB13	SPI SCK
SDA	PC1	SPI MOSI
AD0	PC2	SPI MISO
NCS / CS	PC0	SPI chip select

Lidar

Module wire	NUCLEO-F446RE pin	Function
VCC	5V	Power
GND	GND	Ground
TX, yellow	PA10	Board RX
RX, green	PA9	Board TX

Motors and Encoders

Signal	NUCLEO-F446RE pins
TIM2 CH1/CH2, left wheel PWM/control	PA0, PA1
TIM2 CH3/CH4, right wheel PWM/control	PB2, PB10
TIM3, left encoder	PA6, PA7
TIM4, right encoder	PB6, PB7

Bluetooth

Module pin	NUCLEO-F446RE pin	Function
VCC	3.3V	Power
GND	GND	Ground
TXD	PC5	Board RX
RXD	PC10	Board TX

Build Output Notes

After a successful CLion build, CMake runs objcopy to generate:

• NoeticMaze.hex
• NoeticMaze.bin

These files are generated from the ELF image in the active build directory and correspond to the firmware demonstrated in the Product Quality Video.

Known Issues

• A* path planning may occasionally be triggered at unexpected times, which can cause oscillation in the robot motion. This is especially common when the map contains unknown prior regions or U-shaped turnbacks, and is pending follow-up fixes.