[New Device] MAD Dog GK850W Keyboard

Name of device:

MAD Dog GK850W Keyboard also recognized as "BY Tech GK850"

Link to manufacturer's product page:

https://maddog.pl/produkty/klawiatury/100,klawiatura-mad-dog-gk850w

Please select what type of device/interface the device uses:

ID information:

Bus 003 Device 002: ID 258a:0049 BY Tech GK850

All testing was done with the keyboard connected through USB i haven't tried the wireless USB dongle

This keyboard also has a wired variant.

Please attach screen shots of the device's official control application here:

Lightning modes (translated from polish)

<tc_kb_led1>Stały kolor (still color)</tc_kb_led1>

<tc_kb_led2>Oddech (breathing)</tc_kb_led2>

<tc_kb_led3>Przejście(transition) (</tc_kb_led3>

<tc_kb_led4>Podświetl linię(illuminate line)</tc_kb_led4>

<tc_kb_led5>Deszcz(rain)</tc_kb_led5>

<tc_kb_led6>Podwójne przejście(double transition)</tc_kb_led6>

<tc_kb_led7>Kropla wody(water drop)</tc_kb_led7>

<tc_kb_led8>Migające gwiazdy(flashing stars</tc_kb_led8>

<tc_kb_led9>Cień(shadow)</tc_kb_led9>

<tc_kb_led10>Wąż(snake)</tc_kb_led10>

<tc_kb_led11>Neonowa fala(Neon Wave)</tc_kb_led11>

<tc_kb_led12>Ślad(mark)</tc_kb_led12>

<tc_kb_led13>Sinusoida(sine wave)</tc_kb_led13>

<tc_kb_led14>Skanowanie(scanning)</tc_kb_led14>

<tc_kb_led15>Karuzela(carousel)</tc_kb_led15>

<tc_kb_led16>Wodospad(water fall)</tc_kb_led16>

<tc_kb_led17>Pulsowanie(pulsing)</tc_kb_led17>

<tc_kb_led18>Eksplozja(explosion)</tc_kb_led18>

<tc_kb_led19>Kolizja(collision)</tc_kb_led19>

<tc_kb_led20>Błysk(Flash)</tc_kb_led20>

<tc_kb_led21>Tryb gry(Game mode)</tc_kb_led21> #game mode allows to address leds

<tc_kb_led22>Wyłączone(Off)</tc_kb_led22

Please attach device captures here:

Started App.pcapng.gz

Set whole keyboard to red.pcapng.gz

keyboard Blue.pcapng.gz

keyboard Green.pcapng.gz

keyboard off.pcapng

unplug and replug.pcapng

keyboard white changing brightness.pcapng

game mode adressable .pcapng (Game mode allows for addressing individual leds from the app)

all modes.pcapng

speeds neon wave red.pcapng

I'm also attaching some additional files from the app which may be useful:

All pcap files have comments.

Thanks for creating this software!

Checklist for Step2

Name of device
A link to the vendors product page has been included
The transport bus has been identified and the appropriate label added to the issue.
The device ID's have been included for USB or PCI
Screen shots of the OEM Application are included
There is either, appropriate code examples linked or suitable device captures attached

Edited Sep 28, 2025 by v