This project implements a KISS (Keep It Simple Stupid) modem for LoRa radios, targeting widely available commercial development boards (e.g., Heltec, RAK, Seeed, ESP32, nRF52840). It bridges a KISS serial interface to a LoRa radio, enabling packet radio applications over long-range wireless links.

Features

KISS TNC protocol over UART/USB serial
LoRa radio support (Semtech LR11xx and compatible)
Zephyr RTOS-based for portability and reliability
No dynamic memory allocation (static stack/heap usage)
Designed for low-power, embedded use

Hardware Requirements

Supported LoRa development board (e.g., Heltec, RAK, Seeed, ESP32, nRF52840)
LoRa radio module (LR11xx or compatible)
USB or UART connection to host

Building the Firmware

Prerequisites

Zephyr SDK
west (Zephyr meta-tool)
Board support package for your target board

Steps

Initialize Zephyr workspace (if not already):

west init -l .
west update
west zephyr-export

Build for your board: Replace <board> with your board's Zephyr name (e.g., heltec_wifi_lora32_v2).
```
west build -b <board> .
```
Example:
```
west build -b heltec_wifi_lora32_v2 .
```

Flashing the Firmware

Connect your board via USB.
Flash using west:
```
west flash
```
(You may need to specify --runner or additional options depending on your board.)

Serial Interface

Default baud rate: 115200
KISS protocol framing
Connect to /dev/ttyUSBx or equivalent on your host

Directory Structure

app/ – Zephyr application code
drivers/ – LoRa radio drivers (e.g., LR11xx)
boards/ – Board overlays and configuration
dts/ – Device tree sources
zephyr/ – Zephyr RTOS (west workspace)

License

See LICENSE file for details.

README.md Unescape Escape

LoRa KISS Modem