Berryton

Drive an Airton air-conditioner (most likely a TCL clone) from MQTT / Home Assistant, using an ESP32 running Tasmota wired to the A/C unit's internal serial bus, plus these Berry scripts.

The ESP talks the unit's serial protocol directly (no IR), exposes the A/C to Home Assistant over MQTT, and can either let the A/C regulate on its own sensor or run its own hysteresis thermostat on an external room-temperature source — independently per heating and cooling mode.

Original discussion: arendst/Tasmota#17328 (protocol work with pingus / pingus.org).

First published project — the code is pragmatic rather than elegant, but it has been running daily for a long time. Comments and contributions welcome.

Features

• Mode (auto / cool / dry / fan_only / heat / off), fan speed, louvre swing, temperature setpoint.
• Per-mode regulation (heat and cool configured independently): let the A/C regulate on its own sensor (with an offset), or have the ESP regulate with a hysteresis thermostat on a room temperature read from MQTT or polled over HTTP.
• Home Assistant MQTT auto-discovery — the climate entity appears by itself, no YAML to write.
• Clean HA feedback: HA always sees the user's setpoint (never the internal offset, never the 17/31 °C hysteresis extremes); the current temperature reported to HA is selectable.
• IR-remote / external-change sync: when someone uses the IR remote, the ESP reconciles its state from the A/C feedback frames instead of overwriting the change.
• A periodic Wi-Fi heartbeat keeps the Wi-Fi icon lit on the unit's display.
• A built-in web config page and a live control panel on the Tasmota main page.

Hardware

• An ESP32 (developed on an M5Stack Atom) wired to the A/C unit's serial bus.
• Serial pins (configurable in Berryton.be): RX = GPIO32, TX = GPIO26, 9600 8N1.
• The unit drives the line at 5 V → a bidirectional level shifter is recommended. (It has also run for over a year directly without one — at your own risk; opinions differ on ESP32 5 V tolerance.)

Install / deploy

1. Flash Tasmota (ESP32 build) on the ESP.
2. Upload the .be files to the Tasmota filesystem (UFS) and an autoexec.be that loads them, e.g.:

   load("Berryton.be")          # core (required)
   load("berryton_config.be")   # web config page (optional)
   load("berryton_panel.be")    # main-page control panel (optional)
   load("berryton_emul.be")     # bench emulator, no real A/C (optional)

3. Restart the device (a full Restart, not just BrRestart) so Berry recompiles with a clean heap — the core file is large and a fragmented-heap reload can run out of memory.
4. On first boot, wait ~1-2 minutes for the script to recover the A/C state before the MQTT feedback is correct.

Keep each .be file comfortably under ~30 KB — the on-device Berry compiler is memory-bound. Design notes live in NOTES.md and the observed serial frame layout in FRAMES.md.

Configuration

All settings live in a single BerrytonConfig object, persisted to flash and editable from the Berryton AC page in the Tasmota Configuration menu (provided by berryton_config.be).

Per-mode regulation

For each mode (heat_* / cool_*) you choose a source of regulation:

Source	Who regulates	Uses
ac	the A/C on its own sensor	*_offset (°C added in heat / subtracted in cool, to compensate the unit's high, enclosed sensor)
mqtt	the ESP (hysteresis) on a room temp from MQTT	*_temp_topic, *_hyst
http	the ESP (hysteresis) on a room temp polled over HTTP	*_http_url, *_http_interval, *_hyst

In hysteresis (mqtt/http) mode the ESP forces the unit to 17 °C or 31 °C to run flat-out or coast. The offset and the 17/31 values never leak to Home Assistant — HA always receives the user's real setpoint.

Other settings: a single AC MQTT name (cmnd/<name>/… + tele/<name>/… are derived from it), beep, HA device name & unique id, HA discovery on/off, full vs simplified command set, the temperature reported to HA (A/C sensor vs regulation source), debug logging, and a bench serial_emulation toggle. Saving applies immediately — no Berry restart needed. The day-to-day ionizer / sleep / eco / display flags are toggled from the main-page control panel, not here.

Web UI

A live control panel is added to the Tasmota main page (berryton_panel.be), and a per-mode Berryton AC settings page to the Configuration menu (berryton_config.be):

Control panel (main page)	Config page

Home Assistant

Everything on the web UI is also exposed to Home Assistant via MQTT auto-discovery (ha_discovery_enabled = 1, nothing to add to configuration.yaml): the climate entity, a switch per config-word flag (ionizer / sleep / eco / display / beep), a binary_sensor for the IR-remote Wi-Fi link, and a number for the timer (shows the remaining time, settable in minutes) — so anything you can toggle or see on the panel is also visible/controllable from HA and MQTT.

MQTT topics

With the default prefixes cmnd/Newclim/ and tele/Newclim/:

Direction	Topic	Payload
command	cmnd/Newclim/mode/set · fan/set · swing/set · temperature/set	the value
command	cmnd/Newclim/ionizer/set · sleep/set · eco/set · display/set · beep/set	1 / 0
command	cmnd/Newclim/timer/set	timer in minutes (0 = cancel)
feedback	tele/Newclim/mode/get · fan/get · swing/get	current value
feedback	tele/Newclim/ionizer/get · sleep/get · eco/get · display/get · beep/get	1 / 0
feedback	tele/Newclim/timer/get	remaining timer (minutes)
feedback	tele/Newclim/Actualtemp/get	current temperature shown to HA
feedback	tele/Newclim/Actualsetpoint/get	the user setpoint
feedback	tele/Newclim/remote/get	IR-remote Wi-Fi state (on/off)

Repository layout

File	Role
Berryton.be	core: serial protocol, regulation, MQTT, HA discovery, frame buffering
berryton_config.be	web config page (sections + radios)
berryton_panel.be	live control panel on the Tasmota main page
berryton_emul.be	bench emulator (fake A/C feedback frames, no real unit)
tools/bcheck.sh	compile-check .be files off-device (builds the standalone Berry interpreter)
tools/tb.sh	drive a test ESP32 over HTTP (eval, console, UFS upload)
NOTES.md	design notes & regulation glossary
FRAMES.md	observed Airton serial frame layout

Credits

Protocol work with pingus (pingus.org). Modbus CRC snippet from https://github.com/peepshow-21/ns-flash/blob/master/berry/nxpanel.be.