LoLRa project – Transmitting LoRa packets without radio using CH32V003, ESP8266, or ESP32-S2 MCU
The LoLRa project is a firmware-only LoRa transmission open-source project that works without a Semtech radio and instead relies on an I2S or SPI interface (so not exactly bit-banging) to transmit data with microcontrollers such as WCH CH32V003, or Espressif Systems ESP8266 and ESP32-S2 microcontrollers. LoRa is a proprietary protocol by Semtech, but people have been trying to reverse-engineer the LoRa PHY for years, and this culminated with a LoRa GNU Radio SDR implementation last year. But CNLohr found out you don’t even need a radio to send LoRa packets and you can instead use SPI or I2S interfaces from general-purpose microcontrollers to send packets that can be decoded by commercial off-the-shelf LoRa gateways and other chips. The current implementation is designed for the ITU Region 2 (aka The Americas) targeting the 902-928MHz frequency band, but the code could be changed for Region 1 (EU, Russia, Africa) to target 863-870MHz […]