Overview

ramses_rf is a client library/CLI utility used to interface with some Honeywell-compatible HVAC & CH/DHW systems that use 868MHz RF, such as:

• (Heat) evohome, Sundial, Hometronic, Chronotherm
• (HVAC) Itho, Orcon, Nuaire

It requires a USB-to-RF device, either a Honeywell HGI80 (somewhat rare, expensive) or something running the evofw3 firmware, such as the one from here.

It does three things:

• decodes RAMSES II-compatible packets and converts them into useful JSON
• builds a picture (schema, config & state) of evohome-compatible CH/DHW systems - either passively (by eavesdropping), or actively (probing)
• allows you to send commands to CH/DHW and HVAC systems, or monitor for state changes
• allows you to emulate some hardware devices

For CH/DHW, the simplest way to know if it will work with your system is to identify the box connected to your boiler/HVAC appliance as one of:

• R8810A: OpenTherm Bridge
• BDR91A: Wireless Relay (also BDR91T)
• HC60NG: Wireless Relay (older hardware)

Other systems may well work, such as some Itho Dallderop HVAC systems, use this protocol, YMMV.

It includes a CLI and can be used as a standalone tool, but also is used as a client library by:

• ramses_cc, a Home Assistant integration
• evohome-Listener, an MQTT gateway

Installation

git clone https://github.com/zxdavb/ramses_rf
cd ramses_rf
pip install -r requirements.txt

The CLI is called client.py:

python client.py monitor /dev/ttyUSB0 -o packet.log