LoRaAP
📡 Project Overview
LoRaAP was designed as a portable, low-level LoRa protocol analyzer that could capture, decode, and visualize LoRa radio transmissions in real-time. The project combined custom hardware (RFM95 radio module + ESP8266) with an Android smartphone interface to create a field-deployable tool for LoRa network analysis and debugging.
🔧 Hardware Architecture
Core Components
- RFM95 LoRa Module - Semtech SX1276/77/78/79 based transceiver breakout board
- ESP8266 WiFi Module - Microcontroller handling radio control and data processing
- USB OTG Interface - Direct connection to Android smartphone
- Custom PCB - Breakout board integrating all components
📱 Software Features
Android GUI Application
A custom Android application provided the user interface for:
- Real-time packet capture and display
- LoRa parameter configuration (frequency, SF, bandwidth, coding rate)
- Signal strength (RSSI) monitoring
- Packet logging and export
- Visual spectrum display
- Protocol decoding (LoRaWAN analysis)
ESP8266 Firmware
The embedded firmware handled:
- SPI communication with RFM95 module
- LoRa packet reception and transmission
- Serial protocol for Android communication
- Parameter configuration and storage
- Low-level radio diagnostics
🎯 Use Cases
- Network Debugging - Capture and analyze LoRaWAN traffic for troubleshooting
- Coverage Testing - Field measurements of signal strength and packet reception
- Protocol Analysis - Deep inspection of LoRa physical layer parameters
- Education - Learning tool for understanding LoRa modulation and protocols
- Security Research - Analysis of LoRa network security implementations
� Project Images
LoRa Receiver Hardware
RFM95 + ESP8266 breakout board with antenna
Complete hardware assembly with antenna and USB connection
Hardware Detail View
Board with ESP8266, RFM95 module, and antenna - source code printout visible in background
Detailed view showing ESP8266 + RFM95 integration with source code printout
🔄 Future Development
🚀 Planned Refactor: Tanmatsu Platform
The project is planned to be modernized and ported to the Tanmatsu hardware platform, which offers improved capabilities and a more integrated design.
Tanmatsu is based on the ESP32-P4 SoC with a 400MHz dual-core RISC-V processor, 32MB PSRAM, and includes ESP32-C6 for WiFi/BLE, plus a built-in LoRa module (Ra-01S/Ra-01SH). It features an 800x480 MIPI DSI display, QWERTY keyboard, and extensive expansion capabilities.
Planned Improvements
- Modern hardware platform with better performance
- Enhanced UI with improved visualization
- Support for additional LoRa frequency bands
- Multi-channel simultaneous monitoring
- Extended protocol support (Meshtastic, TTN, etc.)
- Cloud integration for remote monitoring
- Battery-powered portable operation
📚 Technical Background
LoRa Technology
LoRa (Long Range) is a spread spectrum modulation technique derived from chirp spread spectrum (CSS) technology. It provides long-range communication (up to several kilometers) with low power consumption, making it ideal for IoT applications.
Key Parameters
Spreading Factor (SF)- Tradeoff between data rate and range (SF7 = fast/short, SF12 = slow/long)Bandwidth (BW)- Radio channel width (125 kHz, 250 kHz, 500 kHz)Coding Rate (CR)- Forward error correction (4/5, 4/6, 4/7, 4/8)Frequency- Carrier frequency (868 MHz in EU, 915 MHz in US)
🛠️ Development Challenges
The project presented several interesting technical challenges:
- Timing-critical SPI communication on resource-constrained ESP8266
- Efficient packet buffering and serial communication protocol
- Android USB OTG serial driver compatibility
- Real-time visualization of high-speed data streams
- Power management for portable operation
- PCB layout for RF sensitivity
💡 Lessons Learned
This project provided valuable experience in:
- RF hardware design and PCB layout considerations
- Low-level radio protocol implementation
- Android native development and USB communication
- Embedded systems with real-time constraints
- Hardware-software co-design
- Field testing and practical usability concerns
🔗 Project Resources
Source Code & Documentation
The complete source code, hardware schematics, firmware, and Android app are available on GitHub:
📦 GitHub Repository: ReinVelt/loraap →
Includes: ESP8266 firmware, Android app source, PCB designs, and full documentation
"Listening to the radio spectrum, one packet at a time." 📡