ESP32-S3 Autopilot System - Complete Setup Guide

1. Introduction

This guide provides a step-by-step approach to building, programming, and operating an autopilot system based on ESP32-S3 for actuator control and ESP32-2432S028R (CYD - Cheap Yellow Display) for user interaction. The system allows for automated heading correction using a compass, GPS, and actuator while enabling manual overrides and remote control through a WiFi network.

2. System Overview

The autopilot system consists of two main modules:

• ESP32-S3 Module (Autopilot Core):

  • Controls the actuator (linear drive motor) using PWM signals via the IBT-2 motor driver.
  • Reads heading data from a QMC5883L digital compass.
  • Receives GPS data from a Beitian BN-880 GPS module.
  • Implements an algorithm for automatic heading correction.
  • Communicates with the CYD via UDP and serial interface.

• ESP32-2432S028R (CYD - Cheap Yellow Display):

  • Functions as a touchscreen interface.
  • Creates a WiFi network to receive external bearing commands from a phone or PC.
  • Displays real-time heading, error, and autopilot status.
  • Allows modification of parameters such as speed limits and error thresholds.
  • Sends control commands to the ESP32-S3 via UDP packets.

3. Hardware Components

Main Components:

• ESP32-S3 (Autopilot control)
• ESP32-2432S028R (CYD) (2.8-inch TFT Touchscreen Display)
• QMC5883L Compass Sensor (Heading data)
• Beitian BN-880 GPS Module (Positioning and GPS-based heading)
• IBT-2 Motor Driver (Controls actuator motion)
• 12V Linear Actuator (Physically adjusts boat heading)
• Power Supply: 5V for CYD, 12V for the actuator
• Wiring & Connectors: Jumpers, power cables, resistors as needed

4. Wiring and Assembly

ESP32-S3 Wiring:

• Compass (QMC5883L):

  • SCL → GPIO 8
  • SDA → GPIO 9
  • VCC → 3.3V
  • GND → GND QMC sensori is included in Beitan 880, just wire.

• GPS (BN-880): (Beitan 220 is a cheap alternative, but it isn's provided a compass sensor)

  • TX → GPIO 16
  • RX → GPIO 17
  • VCC → 3.3V
  • GND → GND

• Motor Driver (IBT-2):

  • RPWM → GPIO 3
  • LPWM → GPIO 46
  • 12V Power → External power supply

ESP32-2432S028R (CYD) Wiring:

• Power: Connect CYD to a 5V power source.
• Communication: Connect CYD via WiFi to ESP32-S3.
• Touchscreen Inputs: Handled by CYD internally.

5. Software Setup

Step 1: Install Required Software

• Install Arduino IDE
• Install ESP32 board support package (via Boards Manager)
• Install required libraries:
  • Wire.h (I2C communication)
  • EEPROM.h (Memory storage)
  • QMC5883LCompass.h (Compass handling)
  • TinyGPS++.h (GPS handling)
  • WiFi.h & WiFiUDP.h (Network communication)
  • TFT_eSPI.h (Display control)

Step 2: Upload Code

• Load "ESP32-S3_autopilot.ino" onto ESP32-S3 (Handles actuator and heading corrections)
• Load "ESP32_YellowDisplay.ino" onto CYD (Manages touchscreen UI and WiFi communication)

6. System Functionalities

Autopilot Algorithm

• Reads heading from the compass and GPS.
• Computes the error between the current heading and the desired heading.
• Adjusts the actuator's speed proportionally to the error.
• Implements error tolerance and smooth braking to prevent oscillations.

Manual Control

• +1° / -1° Buttons: Moves the actuator manually in small increments.
• +10° / -10° Buttons: Makes larger adjustments.
• Toggle Button: Turns autopilot ON/OFF.

Parameter Configuration

• Speed settings: Adjusts minimum and maximum PWM power.
• Error threshold: Defines when corrections should start.
• Tolerance: Prevents unnecessary micro-adjustments.
• Calibration Mode: Corrects compass offsets, stored in EEPROM.

WiFi & External Bearing

• CYD creates a WiFi AP ("ESP32_AP", "password").
• External devices (smartphone, tablet) can send a bearing via UDP.
• CYD forwards the external bearing to ESP32-S3 for correction.

7. User Guide

Powering the System

1. Connect 12V power to actuator and IBT-2.
2. Connect 5V power to CYD and ESP32-S3.
3. Wait for the display to initialize.

Connecting via WiFi

1. Connect your device to the "ESP32_AP" WiFi network.
2. Open a UDP client app (e.g., "UDP Sender").
3. Send commands to 192.168.4.1, port 4210.

Sending Commands

• ACTION:-1 → Adjust heading by -1°
• ACTION:+1 → Adjust heading by +1°
• ACTION:-10 → Adjust heading by -10°
• ACTION:+10 → Adjust heading by +10°
• ACTION:TOGGLE → Toggle autopilot on/off
• ACTION:CAL → Start compass calibration
• SET:V_max=200 → Change maximum actuator speed
• SET:E_tol=2 → Adjust error tolerance

Calibration Process

1. Press "CAL" on CYD.
2. Rotate the device in all directions for 30 seconds.
3. System stores compass offsets in EEPROM.

Behavior Based on Speed

• Higher speeds → Lower actuator correction.
• Lower speeds → More aggressive correction.

8. Debugging & Optimization

Common Issues & Fixes

Issue	Possible Cause	Solution
No actuator movement	Wrong wiring	Check motor driver connections
Erratic heading readings	Compass uncalibrated	Perform calibration
GPS not working	No satellite fix	Move to an open area
WiFi connection lost	Weak signal	Reduce interference

9. Conclusion

This guide provides everything needed to build, program, and operate the ESP32 autopilot system. With the ability to accept external bearings, manually override controls, and fine-tune navigation parameters, this system is versatile and highly customizable for different use cases.