Firmware Engineer
2 months
2025
2025
LD2420-ESP Integration
Radar sensor integration for precision measurement
ESP32SensorsC++Radar
L
Overview
This project integrates the LD2420 radar sensor with ESP32 for precise human presence detection and distance measurement. The LD2420 uses 24GHz FMCW radar technology, and this implementation provides a clean API for accessing its capabilities.
The Challenge
The LD2420 radar sensor uses a proprietary serial protocol that requires precise timing and frame parsing. Documentation was limited, and integrating real-time radar data with other ESP32 operations required careful task scheduling to avoid data loss.
The Solution
Developed a comprehensive driver library with UART interrupt handling, circular buffer for frame storage, and a state machine for protocol parsing. Implemented calibration routines and sensitivity adjustment APIs for different use cases.
Technology Stack
🔌ESP32
📡Sensors
⚙️C++
📻Radar
Development Process
Step 1
Protocol Analysis
Reverse-engineered the communication protocol by analyzing serial traffic patterns.
Step 2
Driver Development
Built interrupt-driven UART handler with circular buffer for lossless data capture.
Step 3
API Design
Created intuitive callback-based API for presence detection and distance readings.
Step 4
Calibration
Developed auto-calibration routines for different mounting configurations.
Code Highlights
C++
Results & Impact
0m
Max Range
0cm
Resolution
0ms
Response Time
0
Months Dev Time
Key Learnings
- 1
FMCW radar principles and signal processing basics
- 2
Efficient UART handling with DMA on ESP32
- 3
State machine design for protocol parsing
- 4
Hardware abstraction layer patterns in C++