Trådfri control¶

Musium can run a command before starting playback and after a period of inactivity. In combination with Ikea Trådfri wireless control outlets, this is a nice way to turn speakers on and off.

Controlling outlets with libcoap¶

We can send Constrained Application Protocol (CoAP) messages to the Trådfri gateway using coap-client, part of libcoap. You will need the ip address of the gateway, and the security code on the back of the device.

This excellent guide to Trådfri’s CoAP implementation explains how to authenticate, and interact with the gateway. You can also use Pytradfri for a nicer interface to browsing your devices, and to find the id of your outlets. In this example, we want to control device 65539.

To turn an outlet on, we need to send a message with the following payload:

{"3312": [{"5850": 1}]}

A value of 0 instead of 1 turns the outlet off again. Putting everything together, the following command will turn the outlet on:

$ coap-client -u musium -k «redacted»    \
  coaps://192.168.1.100:5684/15001/65539 \
  -m put -e '{"3312": [{"5850": 1}]}'

Note: In my case, the gateway is at 192.168.1.100. I also authenticated previously and created the musium user as described here.

Device groups¶

If you have multiple outlets in a group — for example, one per speaker — and you want to turn the entire group on and off, the paths are different. Instead of 15001 to address a single device, we use 15004 to address a group. Furthermore, the 5850 property that toggles the group is not nested in the 3312 property like with individual outlets. Putting that together, the following command will turn group 131078 on:

$ coap-client -u musium -k «redacted»     \
  coaps://192.168.1.100:5684/15004/131078 \
  -m put -e '{"5850": 1}'

Pre-playback and post-idle scripts¶

To call coap-client before and after playback, we need to create a pre-playback and post-idle script, that we can use with the exec_pre_playback_path setting. Create pre_playback.sh, with the following contents:

#!/bin/sh
# Turn the outlet for the speaker on.
coap-client -u musium -k ...

and replace the coap-client command with the one for your outlet, as shown in the previous section. Create a similar post_idle.sh script, with the payload to turn the outlets off again, and make both scripts executable with chmod +x. Now edit your config file to point to these scripts:

exec_pre_playback_path = /path/to/pre_playback.sh
exec_post_idle_path = /path/to/post_playback.sh
idle_timeout_seconds = 180

Make sure to restart Musium to pick up the new configuration.