Summary
Linux Input 0.18.2-Community shows Nomad [E] now-playing over Bluetooth (mp.write_info works) but album art does not. The same board shows art over USB-C.
Input already has a BLE artwork pacer (768-byte chunks, 120ms gap, retries). On Linux BLE it never runs, because discovery marks the hidraw node as USB.
Environment
- Ubuntu 22.04, GNOME on X11
- Input 0.18.2-Community
- Nomad [E] v1 firmware v0.9.0
- Connection: Bluetooth (
HID_ID=0005:0000303A:00008294, hidraw)
What happens
mp.write_info succeeds every ~1s — title/artist/elapsed show on the widget.mp.write_artwork returns {bytes_written:3072} a few times (~6.5s each), then:
WLDeviceError: Request timed out
RPC operation failed: { code: 'TIMEOUT', message: 'Request timed out' }
JSON-RPC timeout in @worklouder/wl-device-kit is 10s. CHUNK_RAW_BYTE_SIZE is 3072 (base64 cap 4096). That is the USB path.
Root cause
WLDeviceDiscovery.filterWLDevices:
const isUsb = (device.release & 3) === 0;
Firmware encodes USB vs BLE in the low bits of HID bcdDevice / release. On Windows/macOS that bit is trustworthy.
On Linux, BLE keyboards arrive as uhid hidraw (/sys/devices/virtual/misc/uhid/...). node-hid / hidapi reports release = 0 because there is no USB descriptor. (0 & 3) === 0 is treated as USB.
writeArtworkToDevice then calls writeMediaArtwork (3072-byte chunks) instead of the BLE pacer (768-byte chunks). 0.18 already says "album-art transfers are paced over Bluetooth" — that pacer is gated on isUsbConnection === false.
Fix
On Linux, read /sys/class/hidraw/<node>/device/uevent HID_ID bus field:
3 = USB → isUsbConnection = true5 = Bluetooth → isUsbConnection = false- otherwise keep the
release & 3 bit-test
After this override we logged discovered /dev/hidraw2 release=0 isUsb=false, artwork went out as 768-byte chunks with a final 524-byte chunk, zero write_artwork timeouts, and album art appeared on the board.
The kit file that needs the change is unpacked:
resources/app.asar.unpacked/node_modules/@worklouder/wl-device-kit/dist/index.js
(source: src/wl_device_discovery/wl_device_discovery.ts)
Summary
Linux Input 0.18.2-Community shows Nomad [E] now-playing over Bluetooth (
mp.write_infoworks) but album art does not. The same board shows art over USB-C.Input already has a BLE artwork pacer (768-byte chunks, 120ms gap, retries). On Linux BLE it never runs, because discovery marks the hidraw node as USB.
Environment
HID_ID=0005:0000303A:00008294, hidraw)What happens
mp.write_infosucceeds every ~1s — title/artist/elapsed show on the widget.mp.write_artworkreturns{bytes_written:3072}a few times (~6.5s each), then:JSON-RPC timeout in
@worklouder/wl-device-kitis 10s.CHUNK_RAW_BYTE_SIZEis 3072 (base64 cap 4096). That is the USB path.Root cause
WLDeviceDiscovery.filterWLDevices:Firmware encodes USB vs BLE in the low bits of HID
bcdDevice/release. On Windows/macOS that bit is trustworthy.On Linux, BLE keyboards arrive as
uhidhidraw (/sys/devices/virtual/misc/uhid/...). node-hid / hidapi reportsrelease = 0because there is no USB descriptor.(0 & 3) === 0is treated as USB.writeArtworkToDevicethen callswriteMediaArtwork(3072-byte chunks) instead of the BLE pacer (768-byte chunks). 0.18 already says "album-art transfers are paced over Bluetooth" — that pacer is gated onisUsbConnection === false.Fix
On Linux, read
/sys/class/hidraw/<node>/device/ueventHID_IDbus field:3= USB →isUsbConnection = true5= Bluetooth →isUsbConnection = falserelease & 3bit-testAfter this override we logged
discovered /dev/hidraw2 release=0 isUsb=false, artwork went out as 768-byte chunks with a final 524-byte chunk, zerowrite_artworktimeouts, and album art appeared on the board.The kit file that needs the change is unpacked:
resources/app.asar.unpacked/node_modules/@worklouder/wl-device-kit/dist/index.js(source:
src/wl_device_discovery/wl_device_discovery.ts)