Home Assistant Custom Component for controlling Cambridge Audio CXA 61/81 amplifiers

This component allows you to control your Cambridge Audio CXA amplifier through Home Assistant. It now supports both direct serial connections and network connections via WiFi-to-serial converters like the USR-W610.

Features

• Power on/off control
• Input source selection
• Mute control
• Speaker output selection (A, AB, B)
• Volume control (only when used with Cambridge CXN - see limitations below)
• NEW: Network connection support via USR-W610 WiFi-to-serial converter
• NEW: GUI-based configuration (no more YAML editing!)

Important: RS232 Protocol Limitations

The official Cambridge Audio RS232 protocol for CXA amplifiers does NOT support:

• Volume control (no commands to set, query, or adjust volume)
• Volume status queries
• Bass/Treble control
• Balance control

These limitations are part of the Cambridge Audio design - the RS232 interface is primarily for basic control and source switching. For full control including volume, you must either:

1. Configure a Cambridge CXN streamer IP address in the integration settings (CXN provides network control of CXA volume)
2. Use the physical remote control or front panel controls

Installation

HACS Installation (Recommended)

1. Add custom repository jlxq0/cambridge_cxa_network to HACS
2. Install the "Cambridge Audio CXA Network" integration
3. Restart Home Assistant
4. Go to Settings → Devices & Services → Add Integration
5. Search for "Cambridge CXA Network" and follow the configuration wizard

Manual Installation

1. Copy the cambridge_cxa_network folder to your custom_components directory
2. Restart Home Assistant
3. Go to Settings → Devices & Services → Add Integration
4. Search for "Cambridge CXA Network" and follow the configuration wizard

Configuration

This integration now uses the Home Assistant UI for configuration. When you add the integration, you'll be guided through a setup wizard that will:

1. Ask whether you're using a network or serial connection
2. Configure the connection details
3. Test the connection
4. Select your amplifier model (CXA61 or CXA81)
5. Optionally configure CXN IP for volume control

Network Connection Setup (USR-W610)

To use this integration with a USR-W610 WiFi-to-serial converter:

USR-W610 Configuration

1. Connect to your USR-W610's web interface
2. Configure the following settings:
   • Work Mode: TCP Server
   • TCP Server Port: 8899 (default)
   • Serial Port Settings:
     • Baud Rate: 9600
     • Data Bits: 8
     • Stop Bits: 1
     • Parity: None
   • WiFi Settings: Connect to your network

Wiring

Connect your USR-W610 to your Cambridge CXA amplifier:

• USR-W610 TX → CXA RS232 RX (pin 2)
• USR-W610 RX → CXA RS232 TX (pin 3)
• USR-W610 GND → CXA RS232 GND (pin 5)

Use a straight-through RS232 cable (not a null modem cable).

Direct Serial Connection Setup

If you have a direct serial connection between your Home Assistant instance and your Cambridge CXA:

1. Connect your USB-to-serial adapter or serial cable
2. The integration will automatically detect available serial ports
3. Select the correct port from the dropdown during setup

Remote Serial Connection (Legacy Method)

If you need to use ser2net/socat for a remote serial connection, you can still follow the original setup instructions below. However, we recommend using the USR-W610 for a simpler network setup.

ser2net Configuration

For ser2net version 3.x, add to /etc/ser2net.conf:

5000:raw:600:/dev/serial/by-id/<insert id of USB to serial device here>:9600 8DATABITS NONE 1STOPBIT

For ser2net version 4.x, add to /etc/ser2net.yaml:

connection: &cambridge
    accepter: tcp,5000
    enable: on
    options:
      kickolduser: true
      telnet-brk-on-sync: true
    connector: serialdev,
              /dev/serial/by-id/<insert id of USB to serial device here>,
              9600n81,local

socat Configuration

Create /etc/default/socat.conf:

OPTIONS="pty,link=/dev/ttyCXA,raw,ignoreeof,echo=0 tcp:<IP address of the Raspberry Pi>:5000"

Then set up the systemd service as described in the original documentation.

Usage

Once configured, your Cambridge CXA will appear as a media player entity in Home Assistant. You can:

• Turn it on/off
• Select input sources
• Mute/unmute
• Select speaker outputs (A, AB, or B)
• Control volume (if CXN IP is configured)

Troubleshooting

Connection Issues

• Network: Ensure your USR-W610 is on the same network and the IP/port are correct
• Serial: Check that the serial port permissions are correct and no other process is using it

No Response

• Verify your RS232 cable is straight-through (not null modem)
• Check TX/RX connections are not reversed
• Ensure the amplifier is powered on

Enable Debug Logging

Add to your configuration.yaml:

logger:
  default: info
  logs:
    custom_components.cambridge_cxa: debug

Version History

• v2.0.0: Added network support via USR-W610, GUI configuration, async implementation
• v0.5: Original serial-only implementation

Credits

• Original implementation by @lievencoghe
• Network support and GUI configuration by @jlxq0

Support

For issues and feature requests, please use the GitHub issue tracker.