ShinxSU7

This project involves the design and development of a STM32-based smart vehicle that can be controlled manually or autonomously using Bluetooth communication. The vehicle is equipped with ultrasonic sensors for obstacle detection, and it can navigate various paths using Waypoint and Auto modes. The project is based on an innovative communication protocol, system control codes, and advanced sensor calibration to ensure optimal performance.

The vehicle supports various motion tasks and can be controlled in different operational modes: Manual, Waypoint, Auto, and Race.

Contributors

Name	Contributions
IskXCr	Vehicle-side autopilot and calibration design and implementation
ShadowStorm	Driver migration, protocol design and framework implementation
Chanbengz	Controller- and vehicle-side Bluetooth interaction, documentation
GuTaoZi	Controller-side design, implementation and protocol definition

Key Features:

• Bluetooth control for manual and autonomous driving
• Auto obstacle detection using ultrasonic sensors
• Waypoint navigation and Auto mode with obstacle avoidance
• Advanced calibration algorithms for improved motion accuracy

System Functionality

Feat 1: Controller and Vehicle Connection

Bluetooth Communication: Connects the remote controller (LeiJun) and vehicle (SU7). If the handshake times out, an error message is displayed.

Vehicle Movements: The vehicle can move forward, backward, rotate, and stop in multiple directions.

Feat 2: Obstacle Detection

Real-time Distance Display: The vehicle detects obstacles using ultrasonic sensors, displaying distance readings on the screen.

Feat 3: Waypoint Mode

Grid-Based Navigation: The ground is divided into a 4x4 grid, where obstacles are set manually. The vehicle follows predefined waypoints.

Route Setting: Users can set, modify, and send routes to the vehicle.

Feat 4: Auto Mode

Obstacle Detection in Auto Mode: The vehicle autonomously detects obstacles and selects the optimal route to reach the destination using a breadth-first search algorithm.

Feat 5: Race Mode

Line Tracking: The vehicle can track guide lines using grayscale sensors for autonomous movement in Race mode.

Communication Protocol Design

The Bluetooth communication between the controller (LeiJun) and the vehicle (SU7) follows a cyclic protocol where control codes are sent from LeiJun, SU7 responds with acknowledgment codes, data can be sent in both directions.

The controller sends greeting messages every ⅛ second, consuming the message buffer of the vehicle.

A typical communication workflow:

1. The controller sends a control code to the vehicle;
2. The vehicle responds an ACK code;
   • if no data transmission needed, enter the next cycle.
3. Data transmission between the controller and the vehicle;
4. The vehicle sends another ACK, communication completed.

Control Code	Descriptions	Data Length
0x00	Greeting, check if any data needs to be fetched	0 byte
0x01	Set to control mode	0 byte
0x02	Set to waypoint mode	0 byte
0x03	Set to autopilot mode	0 byte
0x04	Set to auto race mode	0 byte
0x05	Set mode start	0 byte
0x06	Set mode STOP	0 byte
0x10	Set all wheel control	4 bytes (4 * uint8_t)
0x11	Set left1 wheel control	1 byte (uint8_t)
0x12	Set left2 wheel control	1 byte (uint8_t)
0x13	Set right1 wheel control	1 byte (uint8_t)
0x14	Set right2 wheel control	1 byte (uint8_t)
0x20	Set a route with $n$ waypoints	$n+1$ bytes, end with 0xFF
0x30	Set autopilot starting and ending point	2 bytes (2 * uint8_t)
0x80	Get obstacle distance	4 bytes (float)
0x81	Get obstacle position	1 byte (uint8_t)
0x90	Get SU7 position	1 byte (2 padding | 2 facing direction | 4 position)
0x9x	Get SU7 state	Reserved

ACK Code	Descriptions
0x00	ACK OK
0x80~0xEF	Sent by the vehicle, notifying the controller to fetch data from the vehicle by echo this code
0xF0~0xFF	Error codes
0xF0	Out of range
0xF1	set mode failed, wait for end or STOP
0xFF	NACK

Usage

Requirements

STM32F103RCT6-based vehicle (SU7), Bluetooth module, ultrasonic sensors, and a controller (LeiJun), compiled using STM32Cube IDE v.1.17.0.

Running the Vehicle

1. Controller Setup:
   • Power on the vehicle and controller.
   • Ensure Bluetooth communication is established.
   • Switch to the desired operational mode (Manual, Waypoint, Auto, or Race) using wake up key.
2. Manual Mode:
   • Press the buttons on the touch panel of the controller to drive the vehicle in all directions.
3. Waypoint Mode:
   • Set obstacles on the grid and define waypoints. Click "Go" to start the vehicle.
4. Auto Mode:
   • Set the start and end location. The vehicle will autonomously navigate the grid, avoiding obstacles.
5. Race Mode:
   • Switch to Race mode to enable line-following behavior for the vehicle.

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For more details, please refer to the doc/ directory and the source code repository.