Onkyo-mqtt

Controls an Onkyo A-9010 amplifier over MQTT using an ESP8266 dev board. Commands are sent over the amplifier's RI port.

• Onkyo-mqtt
  • Setup
  • Usage
  • Home Assistant
  • How does it work

Setup

1. Download this library to ~/Documents/Arduino/libraries/OnkyoRI
2. Fill in the required constants in onkyo-mqtt.ino
3. Flash onkyo-mqtt.ino to an ESP8266 dev board
4. Create a cable that has a 3.5mm mono audio jack at one end, and header pins at the other
5. Connect the ground of the 3.5mm jack to any GND on the dev board, connect the data to any of the GPIO pins
   • The labeling of the GPIO pins on the NodeMCU board is a bit weird
   • Change the ONKYO_PIN constant in onkyo-mqtt.ino to the desired pin. By default it's set to 5, which on the NodeMCU board is D1
6. Plug the 3.5mm jack in the amp's RI port
7. Depending on which sources you want to use (analogue or digital), change the RI-related switches at the back of the amp (see next section)

Usage

To send commands to the amplifier, publish the following messages to the home/livingroom/amp/commands topic:

{
    "state": "on"
}

{
    "state": "off"
}

To turn the amp on and off. Both commands are idempotent, sending on to an amp that's already on doesn't do anything.

{
    "volume": "up"
}

{
    "volume": "down"
}

To change the volume.

{
    "source": "dock"
}

{
    "source": "cd"
}

To change the source. The actual sources that are targeted with these generic names can be chosen by switches at the back of the amp. CD is either line 1 or digital 1. Dock is either line 2 or digital 2. More information is available on page 8 of the user manual. Both of the source commands are idempotent.

Commands that change some state of the amplifier will also result in a message being published to either home/livingroom/amp/state or home/livingroom/amp/source topics. This is required to create a switch in Home Assistant. However, since there's no way to read the current state over RI, it is possible that what's on the topic is out of sync with the actual state of the amp (e.g. using the remote to change sources).

Finally there's a bit of logging information being written to the home/livingroom/amp/logs topic to help debugging.

Home Assistant

To make your amp available in Home assistant, put the following in configuration.yaml:

switch:
  - platform: mqtt
    name: "Amp"
    state_topic: "home/livingroom/amp/state"
    command_topic: "home/livingroom/amp/commands"
    payload_on: '{"state":"on"}'
    payload_off: '{"state":"off"}'
    icon: 'mdi:speaker'

How does it work

More information on how the RI protocol actually works can be found on the library's repository. However, the commands that are listed there are not valid for the A-9010. It seems like the RI implementation varies wildly between devices.

I slightly modified the testing tool that's in the library's repository to scan through the entire command space to use MQTT. This modified version can be found in onkyo-mqtt-test.ino. It will loop over all commands, publishing the current one that's been sent to home/livingroom/amp/live. Controlling the process can be done by sending messages to the home/livingroom/amp topic:

• p to pause/resume the scan
• Anything else will be parsed as a hex string and sent to the amp (e.g. sending 2 will turn up the volume).

Going through all the commands, I've found the following for the A-9010:

Command	Action
0x002	Volume up
0x003	Volume down
0x004	On/off toggle
0x005	Muting toggle
0x020	Change source to CD
0x02f	Turn on
0x0d5	Next input
0x0d6	Previous input
0x0da	Turn off
0x0e3	Line in
0x170	Change source to Dock
0x503	Muting toggle