An Indigo Domotics plugin for the RAMSES-ESP USB gateway, providing local radio control of Honeywell Evohome heating systems via the RAMSES-II protocol — no cloud dependency.
The RAMSES-ESP is an ESP32-S3 + CC1101 RF USB dongle that bridges the Honeywell Evohome 868 MHz radio network to MQTT. This plugin connects to that MQTT stream and creates native Indigo thermostat devices for each Evohome zone — giving you live temperatures, setpoint control, and zone mode tracking entirely locally.
Why local? The Honeywell EU cloud has let us down often enough to stop trusting it. This plugin skips the cloud altogether — if your RAMSES-ESP gateway can hear the TRVs, the plugin works.
- Auto-discovery — Gateway ID and zone thermostats discovered automatically from the radio message stream
- 12-zone support — All Evohome zones created as native Indigo thermostat devices
- Live temperatures — Updated from 30C9 broadcasts (every few minutes)
- Setpoint control — Set heat setpoints via Indigo UI, action groups, schedules, or scripts
- Zone modes — Tracks schedule vs permanent override (from 2349 messages)
- Zone names — Auto-renames devices from Evohome controller (opcode 0004)
- RAMSES folder — All zone devices created inside a dedicated Indigo device folder
- Robust MQTT — Reconnects on its own when the broker restarts, and every device goes offline cleanly when the link drops
- Power-cycle watchdog — If the gateway stays offline, the plugin can cycle the smart plug that powers it (the ramses_esp firmware stops retrying WiFi after a failed reconnect, so only a power cycle recovers it)
- No cloud — Wholly local over MQTT, so it keeps working when the Honeywell EU servers are down
- Bundled paho — paho-mqtt 2.1.0 ships with the plugin, so there is nothing else to install
| Requirement | Details |
|---|---|
| Indigo | 2025.2 or later (API v3.4+) |
| Python | 3.13 (bundled with Indigo 2025.2) |
| Hardware | RAMSES-ESP USB gateway |
| MQTT broker | Any (e.g. Mosquitto running locally) |
| Heating system | Honeywell Evohome with RAMSES-II TRVs |
This plugin, like every CliveS Indigo plugin, reads sensitive values from one shared master file:
/Library/Application Support/Perceptive Automation/IndigoSecrets.py
| File | Purpose | Real data? | Committed to GitHub? |
|---|---|---|---|
IndigoSecrets.py |
Working file the plugin reads at runtime. Keep a backup in a password manager. | YES | NO — listed in .gitignore |
IndigoSecrets_example.py |
Template only — empty placeholders. Shipped in the plugin bundle. | NO | YES |
If you don't have IndigoSecrets.py, copy IndigoSecrets_example.py out of
the plugin bundle into /Library/Application Support/Perceptive Automation/,
rename it to IndigoSecrets.py, and fill in your values. Or skip the file
altogether and type the values into the plugin's configuration dialog — where
both are set, IndigoSecrets.py wins.
If neither source supplies a value the plugin needs, it logs an ERROR naming
the key and telling you to either fill in the matching field or add the key to
IndigoSecrets.py.
- Go to the Releases page and download
RAMSES_ESP.indigoPlugin.zip - Unzip — you will get
RAMSES_ESP.indigoPlugin - Double-click
RAMSES_ESP.indigoPlugin— Indigo will install it automatically - In Indigo: Plugins → Manage Plugins — enable RAMSES ESP
- Open Plugin Config and enter your MQTT broker details
| Setting | Description | Default |
|---|---|---|
| Broker Host | IP address of your MQTT broker | 192.168.1.x |
| Broker Port | MQTT port | 1883 |
| Username | MQTT username (if required) | — |
| Password | MQTT password (if required) | — |
| Gateway ID | Auto-filled on first connection | (auto) |
| Debug Logging | Verbose protocol logging | Off |
Leave Gateway ID blank — the plugin discovers it automatically from the RAMSES/GATEWAY/+/info topic within seconds of connecting.
Evohome TRVs → 868 MHz radio → RAMSES-ESP dongle → MQTT → Plugin → Indigo devices
The plugin subscribes to RAMSES/GATEWAY/<gw_id>/rx and processes four opcodes:
| Opcode | Meaning | Action |
|---|---|---|
30C9 |
Zone current temperature | Updates temperatureInput1 state |
2309 |
Zone setpoint | Updates setpointHeat state |
2349 |
Zone mode / override | Updates zoneMode state |
0004 |
Zone name | Renames the Indigo device |
Setpoint commands are published to RAMSES/GATEWAY/<gw_id>/tx as W 2349 permanent-override RAMSES-II packets, so the Evohome schedule and EU cloud cannot cancel them at the next period boundary.
Each zone device exposes these states:
| State | Type | Description |
|---|---|---|
temperatureInput1 |
Float | Current zone temperature (degC) — shown in device list |
setpointHeat |
Float | Current heat setpoint (degC) |
zoneMode |
String | schedule or permanent override |
zoneControllerId |
String | Evohome controller address e.g. 01:091567 |
zoneName |
String | Zone name from Evohome controller |
lastSeen |
String | Timestamp of most recent message |
online |
String | true / false (MQTT connectivity) |
Use Indigo's native Set Heat Setpoint thermostat action — no custom action needed.
From a Python script:
dev = indigo.devices[963505712] # Zone device ID
indigo.thermostat.setHeatSetpoint(dev, value=21.0)Or directly via the plugin:
plugin = indigo.server.getPlugin("uk.co.clives.ramses.esp")
plugin.executeAction("requestZoneUpdate", deviceId=dev.id)The gateway must be configured to connect to your MQTT broker. Via USB serial (115200 baud):
mqtt user <username>
mqtt password <password>
mqtt broker mqtt://<broker_ip>:1883
reset
Note: Use the
mqtt://URL prefix — bare IP addresses cause a connection failure.
Every log line carries a millisecond timestamp [HH:MM:SS.mmm], so you can
line events up precisely against the other CliveS plugins — Device Activity
Monitor uses the same format.
To turn the prefix off, or back on, at any time:
Plugins → RAMSES ESP → Toggle Timestamps in Log (on/off)
The plugin stores the setting in pluginPrefs (timestampEnabled) and it
survives a restart. It defaults to ON.
| Version | Date | Changes |
|---|---|---|
| 1.5.0 | 27-Jul-2026 | Moved to paho-mqtt 2.1.0, the current release of the MQTT library. Version 2 requires the callback API version to be stated when the client is built and changes the shape of the connect and disconnect callbacks, so all three moved together — leave any one of them behind and the gateway simply never connects, which on this plugin means twelve heating zones quietly stop updating. Connection failures now report the broker's own wording ("Not authorized") instead of a number looked up in a table that version 2 had made unreachable. Fourteen new tests cover the change, taking the suite to 48. If you are upgrading by hand rather than through the release, delete Contents/Packages/paho* first: pip leaves the old copy in place alongside the new one, and the mixture can load the wrong code. |
| 1.4.1 | 21-Jul-2026 | Housekeeping — a refresh of the shared utility module, with no change to how the plugin behaves. Calling the log timestamp filter twice no longer double-stamps every line, a log call with a mismatched placeholder now shows its arguments instead of dropping them, and the module imports cleanly outside Indigo. |
| 1.4.0 | 26-Jun-2026 | A thorough multi-agent code review and the plugin's first proper test suite (34 tests covering the protocol decoders, the setpoint encoder, the gateway-id sanitiser and the watchdog). The headline fix is the power-cycle watchdog, which now does its off-and-on inside a single tick with a guaranteed restore, so a plugin reload or a crash mid-cycle can no longer leave the gateway switched off and the heating dead. A gateway that was already offline when the plugin restarts is now correctly seen as offline rather than being read as online, which used to quietly stop the watchdog ever arming. Alongside that, stray RAMSES domain codes no longer create phantom zone devices, an unknown setpoint no longer wipes a good one to zero, a zone marked offline no longer shows as actively heating in HomeKit, and the setpoint floor moved from 5 to 8 degC to match what the Evohome controller actually applies. Plenty of smaller tidying came along for the ride. |
| 1.3.0 | 12-Jun-2026 | Gateway power-cycle watchdog. If the gateway stays offline beyond a configurable threshold (default 15 minutes), the plugin switches off the Indigo smart plug that powers it, waits a few seconds, and switches it back on. Repeat cycles are spaced a full threshold apart and capped per day (default 3), with Pushover notes on every cycle and a final "needs a human" alert when the cap is reached. Configure it under Plugins -> RAMSES ESP -> Configure. Born of a real incident: a WiFi config change knocked the gateway off the network and the firmware never tried to rejoin (upstream ramses_esp issue #27), so heating data was silently absent for ten days. Also guarded the broker-port preference against non-numeric values. |
| 1.2.11 | 10-Jun-2026 | Housekeeping — lint clean-up and a continuous-integration check added as part of a fleet-wide audit. No change in behaviour. |
| 1.2.10 | 25-May-2026 | Housekeeping — the plugin no longer cycles a zone device's communication every time it writes that device's own properties. Zones are discovered from the radio traffic, so a restart had nothing new to pick up. No change in behaviour. |
| 1.2.9 | 23-May-2026 | Millisecond timestamp [HH:MM:SS.mmm] prefix on every self.logger line via plugin_utils.install_timestamp_filter(); new "Toggle Timestamps in Log" menu item. |
| 1.2.8 | 13-May-2026 | Breaking. The four custom zone states were renamed from zone_mode, zone_controller_id, zone_name and last_seen to zoneMode, zoneControllerId, zoneName and lastSeen, because Indigo state IDs have to be camel case. Any trigger, control page or script reading the old names has to be updated, and the stored history on existing zone devices is lost. |
| 1.2.7 | 10-May-2026 | Plugin version is now read dynamically from Info.plist (self.pluginVersion) — no separate Python constant. Added bundled plugin_utils.py with log_startup_banner() invoked in __init__, plus MenuItems.xml with a Show Plugin Info menu callback. Hardcoded broker IP fallback removed; PluginConfig default cleared. _read_prefs now logs ERROR if no broker host is configured in either IndigoSecrets.py or PluginConfig. IndigoSecrets.py imports split into per-key try/except so a missing single key doesn't blank the rest. PluginConfig version note refreshed (was stuck at 1.1.8). |
| 1.2.6 | 05-May-2026 | Add 5-minute delay before sending "gateway offline" Pushover notification — prevents spurious alerts on brief gateway hiccups. Restored alert is only sent if the offline alert actually fired. |
| 1.2.5 | 08-Apr-2026 | Gateway offline/restored Pushover notifications via Pushover Indigo plugin. |
| 1.2.4 | 04-Apr-2026 | MQTT broker migrated from .140 to .160 after Home Assistant VM decommission; broker now runs natively on the Indigo Mac. |
| 1.1.8 | 24-Feb-2026 | Setpoint command log lines downgraded to debug-only; RAMSES ESP entries no longer interleave with EvoHome script output in event log |
| 1.1.7 | 24-Feb-2026 | Fix HomeKit showing OFF: enable SupportsHvacOperationMode + ShowCoolHeatEquipmentStateUI; re-fetch device after replacePluginPropsOnServer(); add SetHvacMode handler to lock zones to Heat |
| 1.1.6 | 24-Feb-2026 | Add hvacHeaterIsOn (flame indicator) and hvacOperationMode updates on temp refresh for HomeKit |
| 1.1.5 | 24-Feb-2026 | Seed zone_name from device name on startup for zones where 0004 has not yet been received |
| 1.1.4 | 24-Feb-2026 | Send RQ 0004 on startup to populate zone_name states |
| 1.1.3 | 23-Feb-2026 | Fix Zone 0 controller ID being wiped by direct TRV messages; fix misleading success log after publish failure |
| 1.1.2 | 23-Feb-2026 | Downgrade pre-NTP gateway timestamp log from WARNING to INFO; remove unhelpful "Check SNTP config" advice (firmware limitation) |
| 1.1.1 | 23-Feb-2026 | Fix hvacHeaterIsOn state error on new zone device creation |
| 1.1.0 | 23-Feb-2026 | Migrate zone devices to native Indigo thermostat type; add actionControlThermostat(); remove custom setpoint action |
| 1.0.5 | 22-Feb-2026 | Fix last_seen epoch timestamp when gateway NTP not synced; fix zone_mode defaulting to "unknown" |
| 1.0.4 | 22-Feb-2026 | Fix zone name auto-rename; add 0004 opcode parsing |
| 1.0.3 | 22-Feb-2026 | Zone devices created in "RAMSES" folder; last_seen shows clean local time |
| 1.0.2 | 22-Feb-2026 | Fix gateway ID corruption when pref value contained concatenated IDs |
| 1.0.1 | 21-Feb-2026 | Fix MQTT reconnection; add validatePrefsConfigUi() |
| 1.0.0 | 21-Feb-2026 | Initial release |
- RAMSES-III not supported — Honeywell's post-2025 firmware speaks a different protocol, which the ramses_rf library does not handle either
- SNTP on gateway — The RAMSES-ESP firmware accepts the
sntp servercommand but never writes it to NVS, so timestamps can read as 1970 until the firmware fixes it. The plugin works around this by using local system time - Local Override mode — If a TRV dial is turned manually, the TRV enters local override and ignores remote setpoint commands until returned to AUTO position
- Heat only — The plugin handles heat zones. It does not do hot water or cooling
- ramses_esp — The RAMSES-ESP gateway firmware
- ramses_rf — Python RAMSES-II protocol library (used by the HA integration)
- ramses_cc — Home Assistant integration using ramses_rf
- Protocol details from the ramses_rf project
- paho-mqtt 2.1.0 bundled from the Eclipse Paho project (EPL-2.0 / EDL-1.0)
Vibed into existence by CliveS, who knew what he wanted, argued until he got it, and tested it on a real house. Typed at inhuman speed by Claude (Anthropic), who mostly did as it was told.
© 2026 CliveS · MIT licence — copy it, fork it, bend it, break it, fix it, ship it. If it breaks, you get to keep both pieces.