mMPLR-SX127x: LoRa Protocol Stack

Overview

A custom LoRa protocol implementation over SX127x transceivers, featuring a multi-node MAC layer and power-aware transmission scheduling.

This project explores low-level RF communication patterns for IoT applications with severe power and bandwidth constraints.

Technical Implementation

MAC Protocol Layer

• Custom TDMA-inspired slot allocation
• Collision avoidance for multi-node networks
• Acknowledgment and retry mechanisms

Power Optimization

• Sleep scheduling between transmission windows
• Adaptive spreading factor selection
• Duty cycle management for regulatory compliance

Packet Handling

• Fragmentation for payloads exceeding LoRa MTU
• CRC verification and error detection
• Sequence numbering for out-of-order handling

Hardware Setup

• Transceiver: Semtech SX127x (SX1276/SX1278)
• Controller: Raspberry Pi or Arduino
• Interface: SPI communication

Code Structure

mMPLR-SX127x/
├── driver/          # SX127x register-level driver
├── mac/             # MAC protocol implementation
├── packet/          # Packet formatting and parsing
└── examples/        # Multi-node communication demos

Performance Characteristics

• Range: 2+ km line-of-sight
• Data rate: Configurable SF7-SF12
• Power: Optimized for battery operation

Applications

This protocol stack is designed for:

• Environmental sensor networks
• Agricultural monitoring
• Asset tracking systems
• Research deployments

Related Work

This implementation informed the communication layer design for the Niriksana ecological monitoring project.