Dobrica Pavlinušić's random unstructured stuff

Logitech K400r: Revision 5

Very lousy plastic, space bar generated clunk, clunk sound, but otherwise nice wireless keyboard if you don't care much about quality of plastic.

^ Protocol documentation

* {file: logitech_hidpp_2.0_specification_draft_2012-06-04.pdf} from http://6xq.net/git/lars/lshidpp.git/plain/doc/logitech_hidpp_2.0_specification_draft_2012-06-04.pdf

^ Linux software

* https://github.com/pwr/Solaar

.pre
dpavlin@blue:/rest/cvs/Solaar$ sudo ./bin/solaar show
Unifying Receiver
Device path : /dev/hidraw3
USB id : 046d:c52b
Serial : 656F91A9
Firmware : 12.01.B0019
Bootloader : 02.14
Has 1 paired device(s) out of a maximum of 6.
Notifications: (none)
Device activity counters: 1=2

1: Wireless Touch Keyboard K400
Codename : K400
Kind : keyboard
Wireless PID : 4024
Protocol : HID++ 2.0
Polling rate : 8 ms (125Hz)
Serial number: AC5F5069
Firmware: RQK 50.01.B0013
The power switch is located on the edge of top right corner.
Supports 22 HID++ 2.0 features:
0: ROOT {0000}
1: FEATURE SET {0001}
2: FEATURE INFO {0002}
3: DEVICE FW VERSION {0003}
4: DEVICE NAME {0005}
5: BATTERY STATUS {1000}
6: REPROG CONTROLS {1B00}
7: REPROG CONTROLS V3 {1B03}
8: WIRELESS DEVICE STATUS {1D4B}
9: unknown:1DF0 {1DF0} hidden
10: unknown:1DF3 {1DF3} internal, hidden
11: unknown:1E00 {1E00} hidden
12: VERTICAL SCROLLING {2100}
13: HI RES SCROLLING {2120}
14: MOUSE POINTER {2200}
15: FN INVERSION {40A0}
16: NEW FN INVERSION {40A2}
17: ENCRYPTION {4100}
18: KEYBOARD LAYOUT {4520}
19: TOUCHPAD FW ITEMS {6010}
20: TOUCHPAD SW ITEMS {6011}
21: TOUCHPAD WIN8 FW ITEMS {6012}
Has 18 reprogrammable keys:
0: SHOW DESKTOP => ShowDesktop is FN, reprogrammable
1: METRO APPSWITCH => MetroAppSwitch is FN, reprogrammable
2: METRO SEARCH => MetroSearch is FN, reprogrammable
3: METRO SHARE => MetroShare is FN, reprogrammable
4: METRO DEVICES => MetroDevices is FN, reprogrammable
5: METRO SETTINGS => MetroSettings is FN, reprogrammable
6: Previous => Previous is FN
7: Play/Pause => Play/Pause is FN
8: Next => Next is FN
9: Mute => Mute is FN
10: Volume Down => Volume Down is FN
11: Volume Up => Volume Up is FN
12: MEDIA PLAYER => Music nonstandard, reprogrammable
13: Lock PC => WindowsLock nonstandard, reprogrammable
14: SLEEP => Sleep nonstandard, reprogrammable
15: LEFT CLICK => LeftClick mse
16: LEFT CLICK => LeftClick mse
17: RIGHT CLICK => RightClick mse
Battery: 90%, discharging.
.pre

^ Firmware update under Linux

* https://github.com/hughsie/fwupd
* https://blogs.gnome.org/hughsie/2017/05/22/updating-logitech-hardware-on-linux/