There is a room at the top of my house which was originally earmarked for storage (the loft is full of insulation rather than being a useful option). Then I remembered I still had my pico projector and it ended up as a cinema room as well. The pico projector needs really low light conditions with a long throw, so the fact the room only has a single small window is a plus.

Basic Cinema

I bought an “N34” mini PC to act as a media player - I already had a spare DVB-T2 stick to Freeview enable things, and the Kodi box downstairs has all my DVDs stored on it for easy streaming. It’s a Celeron N3450 based box with 4G RAM and a 32GB internal eMMC (though I’m currently running off an SD card because that’s what I initially used to set it up and I haven’t bothered to copy it onto the internal device yet). My device came from Amazon and is branded “Kodlix” (whose website no longer works) but it appears to be the same thing as the Beelink AP34.

Getting Linux onto it turned out to be a hassle. GRUB does not want to play with the EFI BIOS; it can be operated sometimes if manually called from the EFI Shell, but it does not work as the default EFI image to load. Various forum posts recommended the use of rEFInd, which mostly works fine.

Other than that Debian Stretch worked without problems. I had to pull in a backports kernel in order to make the DVB-T2 stick work properly, but the hardware on the N34 itself was all supported out of the box.

The other issue was trying to get Wake-on-Lan to work. The room isn’t used day to day so I want to be able to tie various pieces together with home automation such that I can have everything off by default and a scene configured to set things up ready for use. The BIOS has an entry for Wake-on-Lan, ethtool reported Supports Wake-on: g which should mean MagicPacket wakeup was enabled, but no joy. Looking at /proc/acpi/wakeup gave:

/proc/acpi/wakeup contents 
Device  S-state   Status   Sysfs node
HDAS      S3    *disabled  pci:0000:00:0e.0
XHC       S3    *enabled   pci:0000:00:15.0
XDCI      S4    *disabled
BRCM      S0    *disabled
RP01      S4    *disabled
PXSX      S4    *disabled
RP02      S4    *disabled
PXSX      S4    *disabled
RP03      S4    *disabled  pci:0000:00:13.0
PXSX      S4    *disabled  pci:0000:01:00.0
RP04      S4    *disabled
PXSX      S4    *disabled
RP05      S4    *disabled
PXSX      S4    *disabled
RP06      S4    *disabled  pci:0000:00:13.3
PXSX      S4    *disabled  pci:0000:02:00.0
PWRK      S4    *enabled   platform:PNP0C0C:00

pci:0000:01:00.0 is the network card:

01:00.0 Ethernet controller [0200]: Realtek […] Ethernet Controller [10ec:8168] (rev 0c)

I need this configured to allow wakeups which apparently is done via sysfs these days:

echo enabled > /sys/bus/pci/devices/0000\:01\:00.0/power/wakeup

This has to be done every boot so I just tied it into /etc/network/interfaces.

All of this then enables Home Assistant to control the Kodi box:

Home Assistant Kodi WoL configuration 
wake_on_lan:

media_player:
  - platform: kodi
    name: Kodi (Cinema)
    host: kodi-cinema.here
    port: 8000
    username: kodi
    password: !secret kodi_cinema_pass
    enable_websocket: false
    turn_on_action:
      service: wake_on_lan.send_magic_packet
      data:
        mac: 84:39:be:11:22:33
        broadcast_address: 192.168.0.2
    turn_off_action:
      service: media_player.kodi_call_method
      data:
        entity_id: media_player.kodi_cinema
        method: System.Shutdown

My Home Assistant container sits on a different subnet to the media box, and I found that the N34 wouldn’t respond to a Wake-on-Lan packet to the broadcast MAC address. So I’ve configured the broadcast_address for Home Assistant to be the actual IP of the media box, allowed UDP port 9 (discard) through on the firewall and statically nailed the ARP address of the media box on the router, so it transmits the packet with the correct destination MAC:

ip neigh change 192.168.0.2 lladdr 84:39:be:11:22:33 nud permanent dev eth0

I’ve still got some other bits to glue together (like putting the pico projector on a SonOff), but this gets me started on that process.

(And yes, the room is a bit cosier these days than when that photograph was taken.)