lora-modules

Goal: Establish long-range, low-power radio communication using Semtech LoRa transceivers (SX1276/SX1278, RFM95, SX1262) via SPI.

1. Hardware Interface

LoRa chips communicate via SPI and use a few extra interrupt pins to notify the MCU when a packet is received.

• SCK, MISO, MOSI -> Hardware SPI.
• NSS (Chip Select).
• RST (Reset pin).
• DIO0, DIO1 (Data Input/Output interrupts).

Logic Level: Strictly 3.3V.

2. Point-to-Point vs LoRaWAN

• LoRa (Physical Layer): Two nodes talking directly to each other using the RadioHead (RH_RF95) or LoRa library. No network joining, no encryption by default.
• LoRaWAN (MAC Layer): Connecting an edge node to public networks like The Things Network (TTN) or Helium. Requires the LMIC (LoRaMAC-in-C) library. Uses AES-128 encryption and requires AppSKey/NwkSKey provisioning.