sony-tv-rs232

Async Python library to control Sony Bravia TVs over RS232 serial, built on serialkit (the serial-toolkit distribution on PyPI) and serialx.

Installation

pip install sony-tv-rs232

# To talk to a TV over an ESPHome serial proxy:
pip install 'sony-tv-rs232[esphome]'

Requires Python 3.14+.

Quick start

import asyncio
from sony_tv_rs232 import SonyTV, InputSource


async def main():
    tv = SonyTV("/dev/ttyUSB0")
    await tv.connect()

    await tv.enable_standby_listening()  # so power_on works from standby
    await tv.power_on()
    await tv.set_volume(20)
    await tv.select_input_source(InputSource.HDMI1)

    await tv.disconnect()


asyncio.run(main())

CLI

python -m sony_tv_rs232 /dev/ttyUSB0                 # query + print status
python -m sony_tv_rs232 socket://192.168.1.29:5000   # raw TCP bridge
python -m sony_tv_rs232 'esphome://192.168.1.29/?port_name=TTL'
python -m sony_tv_rs232 /dev/ttyUSB0 --power on
python -m sony_tv_rs232 /dev/ttyUSB0 --input HDMI1
python -m sony_tv_rs232 /dev/ttyUSB0 --diagnose      # raw wiring diagnosis

Protocol notes

Sony's consumer RS-232C protocol is effectively set-only: the TV acknowledges every Set command but most models ignore query packets, and the answer frame carries no echo of which command it answers. The library:

• updates state optimistically when a Set is acknowledged, and from query replies on the Pro Bravia displays that answer them;
• runs every command as an exclusive exchange, because answers are unaddressed — holding the wire for one send-and-read round, anchored on arrival order, is what keeps a dropped or garbled answer from being read as the next command's;
• paces commands ≥ 500 ms apart, as the Sony spec requires;
• resends the first command after an idle gap once: a TV that has slept loses the leading bytes of the frame that wakes it and answers PARSE_ERROR, so that reply is treated as "send it again";
• reconnects automatically when the serial link drops.

All of that machinery lives in serialkit; this library is the Sony command surface plus a checksum-discriminated answer framer.

Connection handling

from sony_tv_rs232 import CommandTimeoutError, ConnectionLostError, SonyCommandError

try:
    await tv.set_volume(50)
except SonyCommandError as err:  # TV returned a non-zero answer code
    ...
except CommandTimeoutError:  # no answer in time (common on set-only TVs)
    ...
except ConnectionLostError:  # serial link dropped
    ...

Subscribe to state changes; callbacks receive a TVState snapshot, or None when the connection is lost:

unsub = tv.subscribe(lambda state: print("state:", state))

Serial connection

Sony Bravia sets use 9600 baud, 8N1. The library accepts any serialx-compatible URL (/dev/ttyUSB0, socket://host:port, esphome://host/?port_name=TTL).

Development

uv run --python 3.14 pytest
uv run --python 3.14 --with mypy mypy --strict src/
uvx ruff check && uvx ruff format --check

The RS-232C protocol reference is in docs/.

License

MIT